Paleontology news

Evidence is weak for tropical rainforest 65 million years ago in Africa's low-latitudes

2010-10-22T17:37:00.002+02:00

The landscape of Central Africa 65 million years ago was a low-elevation tropical belt, but the jury is still out on whether the region's mammals browsed and hunted beneath the canopy of a lush rainforest. The scientific evidence for a tropical rainforest at that time is weak and far from convincing, says paleobotanist Bonnie F. Jacobs at Southern Methodist University in Dallas.

Fossil pollen from Central and West Africa provide no definitive evidence for communities of rainforest trees at the beginning of the Cenozoic, says Jacobs, an expert in the paleobotany of Africa soon after dinosaurs had gone extinct. It was the start of the age of mammals, and Africa was largely an island continent.

Many Cenozoic mysteries remain to be solved

The rainforest mystery is characteristic of the scientific uncertainty and unknowns surrounding Africa's ancient flora during the period called the Cenozoic. There are large gaps in the fossil record, says Jacobs, a co-author of "A Review of the Cenozoic Vegetation History of Africa." She is an associate professor in SMU's Roy M. Huffington Department of Earth Sciences.

The review, a chapter in "Cenozoic Mammals of Africa" (University of California Press, 2010), is the first of its kind since 1978 to review and interpret the Cenozoic paleobotanical record of Africa with paleogeographic maps showing paleobotanical site distributions through time. Jacobs co-authored the paper with Aaron D. Pan, a paleobotanist at the Fort Worth Museum of Science and History, and Christopher R. Scotese, in the Earth Sciences Department at the University of Texas at Arlington.

The 1008-page "Cenozoic Mammals of Africa" is the first comprehensive scientific reference of its kind since 1978, comprising 48 chapters by 64 experts. The volume summarizes and interprets the published fossil research to date of Africa's mammals, tectonics, geography, climate and flora of the past 65 million years.

Details sparse, but big picture emerges for past 65 million years

Paleobotanical data for Africa are generally meager and uneven for the Cenozoic, according to Jacobs and her co-authors.

In an original series of maps, they chart each Cenozoic Africa paleobotanical locale described in the published research to date. There are a mere 82 sites in all. Most of the sites date to 50 million years ago. Fewer date to 20 million, 30 million, 10 million and — perhaps most important — 2 million years ago, when the human family was evolving.

"Africa is disappointingly undersampled," say Jacobs and her colleagues. "This vast continent, roughly three times the area of the United States, has so far been documented by only a handful of Paleogene plant and vertebrate localities, and it has a Neogene record heavily biased toward the depositional basins of the East African Rift."

Shift from descriptive to analytic approach driven by holistic view

For a continent so important for its role in the evolution of mammals, the scarcity of plant fossil data stands in sharp contrast.

"As impressive as is the contemporary mammalian diversity of Africa, it is dwarfed by that of the Cenozoic," write the volume's editors, paleozoologist Lars Werdelin, the Swedish Museum of Natural History, and paleontologist William Joseph Sanders, the University of Michigan. Africa today represents 20 percent of the world's land mass, is the only continent to occupy both the north and south temperate zones, and is home now to more than 1,100 mammalian species, they write in the introduction.

Africa's paleobotanical record is key to a holistic understanding of ancient mammals, says H.B.S. Cooke in the preface. A mammal expert, Cooke was editor of the earlier 1978 scientific reference, "Evolution of African Mammals" (Harvard University Press).

"Most striking over the past years has been a shift in studying fossils from a largely descriptive taxonomy to a more analytical approach, including consideration of faunal associations, their distribution in time and space, and the environmental and climatic factors that prevailed and changed through time," Cooke writes in the preface to the new book. " … African prehistory has become more a study of paleobiology than mere paleontology."

To view a map or images of Cenozoic leaf fossils from Jacobs' field work in Africa go to SMU Research on flickr.

More scientific exploration needed to fill gaps

Scientific exploration to learn more about Africa's ancient vegetation is on the increase, say Jacobs and her co-authors. That should start to fill gaps in understanding, including the mystery of Africa's palms.

While palm trees are common in wet tropical forests worldwide, that's not the case in Africa today. Palm trees have not been found in abundance in Africa for the past 24 million years, regardless of whether the regional vegetation was forest, say the authors. Oddly, though, abundant palm samples have been found in some African locations dating between 65 million and 25 million years ago, including at Chilga in Ethiopia by Jacobs and Pan.

The implications of that difference are significant for the various endemic mammals of that time, many of which were absent by 23 million years ago, say the authors.

"We are fortunate that the sampling scale of most fossil localities is at the plant community level, and larger-scale changes took place one community at a time," they write. "Thus, as Africa becomes better sampled, the uneven record will ultimately become a more complete narrative of dynamic change at the community and ecosystem levels."

esciencenews.com

Britain's 'earliest hospital' discovered

2010-10-21T17:52:00.002+02:00

Radio carbon analysis of site in Winchester provides date range of AD 960-1030 – preceding Norman conquest.

Archaeologists have uncovered a site that may house Britain's earliest known hospital. Radio carbon analysis at the former Leper Hospital at St Mary Magdalen in Winchester, Hampshire, has provided a date range of AD 960-1030 for a series of burials, many exhibiting evidence of leprosy.

A number of other artefacts, pits, and postholes relate to the same time, including what appears to be a large sunken structure underneath a medieval infirmary.

Most historians and archaeologists had believed hospitals in Britain only dated from after the Norman conquest of 1066.

"This is an important archaeological development," said Dr Simon Roffey from the University of Winchester, which conducted the dig.

"Historically, it has always been assumed that hospitals were a post-conquest phenomenon, the majority founded from the late 11th century onwards.

"However, our excavations have revealed a range of buildings and, more significantly, convincing evidence for a foundation in the 10th century.

"Our excavations at St Mary Magdalen offer an intriguing insight into a little known aspect of the history of both Winchester and England. It is undoubtedly a site of national importance."

Among the earliest known hospitals in the UK is Harbledown in Canterbury, founded by Lanfranc in the 1070s, following the Norman conquest.

Professor Nicholas Orme, a leading researcher on medieval hospitals, added: "I have only studied the documentary evidence but I could not find any such evidence for a hospital before 1066 except perhaps as an activity within a monastery or minster.

"A late Anglo-Saxon hospital would surely be a first for archaeology and indeed for history."

Winchester was the capital of England throughout a large part of the Anglo-Saxon period and after the Norman conquest. The capital was moved to London from the Hampshire city in the 12th century.

guardian.co.uk

Swiss unearth 5,000-year-old door

2010-10-20T18:56:00.001+02:00

Archeologists find 'remarkable' Neolithic wooden door as old as Stonehenge at site of planned car park in Zurich.

Archaeologists in Zurich have unearthed a 5,000-year-old door that may be one of the oldest ever found in Europe.

The ancient poplar wood door is "solid and elegant" with well-preserved hinges and a "remarkable" design for holding the boards together, archaeologist Niels Bleicher said today.

Using tree rings to determine its age, Bleicher believes the door could have been made in 3,063BC, just as construction on Stonehenge began.

"The door is very remarkable because of the way the planks were held together," he told the Associated Press.

Harsh climatic conditions at the time meant people had to build solid houses that would keep out much of the cold wind that blew across Lake Zurich, and the door would have helped, Bleicher said. "It's a clever design that even looks good."

The door was part of a settlement of so-called "stilt houses" frequently found near lakes about a thousand years after agriculture and animal husbandry were first introduced to the pre-Alpine region.

It is similar to a door found in nearby Pfaeffikon, while a third – made from one solid piece of wood – is believed to be even older, possibly 3,700BC, said Bleicher.

The latest door was found at the dig for what is intended to be a new underground car park for Zurich's opera house.

Archaeologists have found traces of at least five Neolithic villages believed to have existed at the site between 3,700 and 2,500 years BC, including objects such as a flint dagger from what is now Italy and an elaborate hunting bow.

guardian.co.uk

New bony-skulled dinosaur species discovered in Texas

2010-04-20T09:07:00.002+02:00

Paleontologists have discovered a new species of dinosaur with a softball-sized lump of solid bone on top of its skull, according to a paper published in the April issue of the journal Cretaceous Research. The species was a plant-eating dinosaur about as big as a medium-sized dog that lived 70 to 80 million years ago, said Nicholas Longrich of Yale University, lead author of the paper. The team discovered two skull fragments in Big Bend National Park in southwest Texas in 2008. They compared them to dozens of fossils from related species found in Canada and Montana before confirming that the fossils represented a new genus of pachycephalosaur, a group of bipedal, thick-skulled dinosaurs.

The researchers named the new species Texacephale langstoni. ("Texacephale" means "Texas head" and "langstoni" is in honor of Wann Langston, a fellow paleontologist.) The new species is one of about a dozen known to have solid lumps of bone on top of their skulls, which Longrich speculates was probably used to ram one another head-on in a manner similar to modern-day musk oxen and cape buffalo.

The discovery of the new species lends further weight to the idea, which has gained popularity in recent years, that dinosaurs found in Canada and the northern United States were distinct from their southern neighbors.

"Instead of roaming across the North American continent, we see pockets of different dinosaurs that are pretty isolated from one another," Longrich said. "Every time we get good fossils from Texas, they end up looking very different from those to the north."

Because fossils from the Big Bend region are rare and tend to be poorly preserved, scientists do not have a complete picture of the different species that once inhabited the area, Longrich said.

But the team may have uncovered an important piece of the puzzle with their discovery. They found that this particular group of dinosaurs, which was previously thought to have originated in Asia, likely evolved in North America.

Longrich expects more related species to be discovered in the future as fossils from the Texas site and elsewhere continue to be examined.

"I think we underestimate how many different species there were," he says.

Yale University

Stalagmite reveals carbon footprint of early Native Americans

2010-04-16T08:48:00.002+02:00

A new study led by Ohio University scientists suggests that early Native Americans left a bigger carbon footprint than previously thought, providing more evidence that humans impacted global climate long before the modern industrial era. Chemical analysis of a stalagmite found in the mountainous Buckeye Creek basin of West Virginia suggests that native people contributed a significant level of greenhouse gases to the atmosphere through land use practices. The early Native Americans burned trees to actively manage the forests to yield the nuts and fruit that were a large part of their diets.

"They had achieved a pretty sophisticated level of living that I don't think people have fully appreciated," said Gregory Springer, an associate professor of geological sciences at Ohio University and lead author of the study, which was published a recent issue of the journal The Holocene. "They were very advanced, and they knew how to get the most out of the forests and landscapes they lived in. This was all across North America, not just a few locations."

Initially, Springer and research collaborators from University of Texas at Arlington and University of Minnesota were studying historic drought cycles in North America using carbon isotopes in stalagmites. To their surprise, the carbon record contained evidence of a major change in the local ecosystem beginning at 100 B.C. This intrigued the team because an archeological excavation in a nearby cave had yielded evidence of a Native American community there 2,000 years ago.

Springer recruited two Ohio University graduate students to examine stream sediments, and with the help of Harold Rowe of University of Texas at Arlington, the team found very high levels of charcoal beginning 2,000 years ago, as well as a carbon isotope history similar to the stalagmite.

This evidence suggests that Native Americans significantly altered the local ecosystem by clearing and burning forests, probably to make fields and enhance the growth of nut trees, Springer said. This picture conflicts with the popular notion that early Native Americans had little impact on North American landscapes. They were better land stewards than the European colonialists who followed, he said, but they apparently cleared more land and burned more forest than previously thought.

"Long before we were burning fossil fuels, we were already pumping greenhouse gasses into the atmosphere. It wasn't at the same level as today, but it sets the stage," Springer said.

This long-ago land clearing would have impacted global climate, Springer added. Ongoing clearing and burning of the Amazon rainforest, for example, is one of the world's largest sources of greenhouse gas emissions. Prehistoric burning by Native Americans was less intense, but a non-trivial source of greenhouse gases to the atmosphere, he said.

Ohio University

The new T. rex: A leech with an affinity for noses

2010-04-15T18:09:00.001+02:00

The new T. rex has ferociously large teeth lining a single jaw. But its length is less than 2 inches. Tyrannobdella rex, which means tyrant leech king, is a new species of blood sucker that lives in the remote parts of the Upper Amazon. Although its regular host remains unknown, it was discovered three years ago in Perú when a 44.5 millimeter leech was plucked from the nose of a girl who had recently been bathing in a river. The new species, described in PLoS ONE, has led to revising the group of leeches that has a habit of feeding from body orifices of mammals. "Because of our analysis of morphology and DNA, we think that Tyrannobdella rex is most closely related to another leech that gets into the mouths of livestock in Mexico," says Anna Phillips, a graduate student affiliated with the American Museum of Natural History and the first author of the paper. "We think the leech could feed on aquatic mammals, from their noses and mouths for example, where they could stay for weeks at a time."

Discoveries of new leech species are not uncommon occurrences. Although there are 600 to 700 species of described leeches, it is thought that there could be as many as10,000 species throughout the world in marine, terrestrial and fresh water environments. Tyrannobdella rex was first brought to the attention of Mark Siddall, curator in the Division of Invertebrate Zoology at the Museum, when he received a specimen collected by Dr. Renzo Arauco-Brown, a Peruvian medical doctor from the School of Medicine at the Universidad Peruana Cayetano Heredia in Lima who was working at a clinic in Chanchamayo province. Siddall immediately recognized it as a new species. His student Alejandro Oceguera-Figueroa described its weird morphology—a single jaw with eight very large teeth, and extremely small genitalia. Two earlier cases from 1997 were re-discovered from different clinics in the western Amazon, one from Lamas province and the other from Yochegua province.

The new genus and species, Tyrannobdella rex, has led to a revision of the phylogenetic relationships among several leech families. Both morphological and genetic data show that this species is most closely related to Pintobdella chiapasensis, a leech from Chiapas that is typically hosted by tapir but also infests cows. Part of the research for this paper involved a Mexican expedition by Phillips and Oceguera-Figueroa to gather new specimens for DNA analysis. Close by on the phylogenetic tree, this group is related to leeches found in India and Taiwan like Dinobdella ferox, the terrible, ferocious leech that is well-known for feeding on mucus membranes and getting into various human orifices. All of these species, and others from Mexico, Africa, and the Middle East, make up the family Praobdellidae, a group of leeches that seems to share this feeding behavior and which can pose a risk to human health in certain parts of the world.

The evolutionary relationship among leeches that currently inhabit distant regions suggests that the common ancestor of this group must have lived when the continents were pressed together into a single land mass, before Pangaea broke up.

"We named it Tyrannobdella rex because of its enormous teeth. Besides, the earliest species in this family of these leeches no-doubt shared an environment with dinosaurs about 200 million years ago when some ancestor of our T. rex may have been up that other T. rex's nose," says Siddall. "The new T. rex joins four other species that use this abbreviated name, including two Miocene fossils (a snail and a scarab beetle), a living Malaysian formicid ant, and, of course, the infamous Cretaceous theropod dinosaur that was described in 1905 by an earlier curator of the American Museum of Natural History."

American Museum of Natural History

300 million year old ancestor revealed in new 3-D model

2010-04-14T10:29:00.004+02:00

An early ancestor of the cockroach that lived around 300 million years ago is unveiled in unprecedented detail in a new three-dimensional 'virtual fossil' model, in research published today in the journal Biology Letters.

Scientists at Imperial College London have made a comprehensive 3D model of a fossilised specimen called Archimylacris eggintoni, which is an ancient ancestor of modern cockroaches, mantises and termites. This insect scuttled around on Earth during the Carboniferous period 359 - 299 million years ago, which was a time when life had recently emerged from the oceans to live on land.

The study reveals for the first time how Archimylacris eggintoni's physical traits helped it to thrive on the floor of Earth's early forests. The fossils of these creatures are normally between 2cm and 9cm in length and approximately 4cm in width.

The lead author of the study, Mr Russell Garwood, a PhD student from the Department of Earth Science and Engineering at Imperial College London, says, "The Carboniferous period is sometimes referred to as the age of the cockroach because fossils of Archimylacris eggintoni and its relatives are amongst the most common insects from this time period. They are found all over the world. People joke about it being impossible to kill cockroaches and our 3D model almost brings this one back to life. Thanks to our 3D modelling process, we can see how Archimylacris eggintoni's limbs were well adapted for all terrains, as it was not only adept in the air but also very agile on the ground."

sciencecodex.com

Egyptians Discover Roman-Era Mummy

2010-04-13T15:27:00.001+02:00

Egyptian archaeologists discovered an intricately carved plaster sarcophagus portraying a wide-eyed woman dressed in a tunic in a newly uncovered complex of tombs at a remote desert oasis, Egypt's antiquities department announced Monday.

It is the first Roman-style mummy found in Bahariya Oasis some 186 miles (300 kilometers) southwest of Cairo, said archaeologist Mahmoud Afifi, who led the dig. The find was part of a cemetery dating back to the Greco-Roman period containing 14 tombs.

"It is a unique find," he told The Associated Press, confirming that initial examinations indicate a mummy is inside the coffin.

The carved plaster sarcophagus is only 3 feet (1 meter) long and shows a woman wearing a long tunic, a headscarf, bracelet and shoes, as well as a beaded necklace. Colored stones in the sarcophagus' eyes gave the appearance she is awake.

Afifi said they had not dated the new find yet, but the burial style indicated she belonged to Egypt's long period of Roman rule lasting a few hundred years and starting 31 B.C.

He said his team first thought they had stumbled across a child's tomb because of its diminutive stature, but the decorations and features indicated it was a woman.

Afifi said it was still unclear who the woman was but said it was most likely she was a wealthy and influential member of her society, judging by the effort taken on the sarcophagus.

Mummies of people of diminutive stature have been unearthed in other parts of Egypt, where they appeared to have importance in local religions at the time, he added.

The archaeologists also found a gold relief showing the four sons of the Egyptian god Horus, other plaster masks of women's faces, several glass and clay utensils and some metal coins.

The metal coins are being checked to see whether they can date the era of the tomb more precisely.

Larger Tomb Complex

Afifi said the find suggested the presence of a larger tomb complex, but said humid weather in the area may have destroyed similar sites.

He said none of the other 13 graves were as complete as that of the woman.

The find was made after archaeologists had made a series of exploratory digs ahead of a local council plan to build a youth center on the land. The area is known for its relics from the Greco-Roman period.

Bahariya Oasis rocketed to fame a decade ago with the discovery of the "Valley of the Golden Mummies," a vast cemetery that has yielded up hundreds of mummies, many covered in gold leaf, from the Greco-Roman period.

Those sarcophagi were decorated in a more traditional ancient Egyptian style, rather than the Roman style of the current find.

The discoveries from this period indicate the comparative wealth and prosperity of the oases at the time due to their location on major desert trading routes.

cbsnews.com

Ancient city yielding new clues in Michoacan, Mexico

2010-04-13T15:24:00.002+02:00

Colorado researchers have discovered and partially mapped a major urban center once occupied by the Purépecha of Mexico, a little-known people who fought the Aztecs to a standstill and who controlled much of western Mexico until diseases brought by the Spanish decimated them.

The "proto-urban center," which researchers have not yet named, sat on volcanic rock on the shores of Lake Pátzcuaro in the central Mexican state of Michoacan, now a tourist destination. It supported as many as 40,000 people until the consolidation of the Purépecha empire about AD 1350 led most of its inhabitants to relocate to the new capital of Tzintzuntzan, six miles away.

"What's really interesting about the site is that it gives us a window into the pre-state period when social complexity was increasing and people were congregating together and starting to modify the landscape," said archaeologist Christopher Fisher of Colorado State University, who will present the findings this week at a St. Louis meeting of the Society for American Archaeology.

Finding that the urban center's population fell as the capital, Tzintzuntzan, grew will also help rewrite the history of the Purépecha, who were also known as Tarascans, said archaeologist Gary Feinman of Chicago's Field Museum, who was not involved in the research.

It indicates, he said, that concentration of the population -- rather than population growth as had previously been believed -- "was a critical element in the concentration of power, particularly in Mesoamerica, where you did not have domesticated animals. People were absolutely critical for moving goods, constructing things and producing food."

Despite the fact that the Purépecha empire was as large and powerful as that of the Aztecs, they "have gotten the short end of the stick as far as public attention goes," Fisher said.

Much of what we know about the Aztecs comes from the colonial records of the Spanish expeditionary force, he noted, but the Spaniards -- who encountered the Aztecs first -- had little contact with the Purépecha until the civilization was already doomed by disease.

Yet the Purépecha not only controlled most of western Mexico, but had a strongly fortified border with the Aztec empire and ultimately defeated the Aztec army in a fierce battle in the late 15th century.

Part of their strength came from their skill as coppersmiths and, despite the fact that they were fierce enemies, the Aztecs traded extensively with them to acquire copper tools, bells and other valuable objects.

Fisher and his team discovered the site last summer as part of their ongoing survey of the Lake Pátzcuaro basin.

Because the lake level has been dropping, the Purépecha site now sits a couple of miles east of the lake -- Fisher is vague about the precise location because of fears of looting -- but at its height was probably no more than a quarter mile from the shore.

The site sits on a landform called malpais, a young, rugged volcanic landscape "that looks like gravel dumped into a big pile," he said.

Because the land is not suitable for agriculture, the foundations of structures have been largely preserved.

The site encompasses about 5 square kilometers (about 1,200 acres). Using rugged computers and specialized GPS receivers, the team has carefully mapped about a fifth of the site, recording more than 1,300 features, including house mounds, room blocks, buildings, small temples, plazas and agricultural terraces.

Such detailed mapping "is quite revolutionary because it gives us a chance to see what the economic picture was, and the social differentiation," said archaeologist Barbara Stark of Arizona State University, who was not involved in the research. "It's hard to describe how important that is for our understanding of these societies."

Most of the site dates from AD 1000 to about 1350, when it began to shrink as the population moved elsewhere. By 1500, it was largely abandoned.

Most of the rest of the empire disappeared soon after. Smallpox and other diseases that were spread to the Aztecs by the Spanish were transmitted to the Purépecha as well, killing 80% to 90% of the population. By the time the Spanish attacked the Purépecha, there was hardly anyone left to resist.

latimes.com

Human fossil discovery -- evidence of new Homo species

2010-04-12T09:47:00.001+02:00

Two partial skeletons have been discovered in the cave deposits in the Cradle of Humankind World Heritage Site near Johannesburg, in the Republic of South Africa by members of the University of the Witwatersrand, Johannesburg. The human fossils, close to 2 million years old, have been classified as a new species: Australopithecus sediba. Australopithecus means "southern ape" and Sediba, taken from the local South African language seSotho means "natural spring, fountain or wellspring".

The findings represent some of the most significant scientific discoveries of recent years and were published today in the scientific journal Science.

Dr Robyn Pickering of the School of Earth Sciences at the University of Melbourne who was one a team of international and Australian scientists to accurately date the sediments surrounding the fossils says, "We are now able to fill in the gap of what happened 2 million years ago in the beginnings of our species."

"It has never been clear where our own genus Homo came from – this new discovery, Australopithecus sediba could answer these questions," she says.

Researchers say this species appears to be a transitional form, maybe the best yet found, between early australopithecines and early members of the genus Homo, thereby replacing other candidates such as Homo habilis (the tool making 'handy' man from east Africa) as the distant ancestor of Homo sapien.

The Sediba fossils are exceptionally well preserved, and therefore provide a unique insight in the period when the earliest members of our genus evolved.

Sediments from surrounding and supporting the fossils were analysed by several research teams.

Using a state-of-the-art uranium lead dating technique, conducted independently and in parallel by Dr Pickering at the University of Melbourne and her former PhD supervisor Professor Jan Kramers from the University of Bern in Switzerland, they produced an identical age result confirming the sediment was close to 2 million years old.

"Together with palaeomagnetic dating of the sediments more closely surrounding the fossils by Andy Herries of UNSW and our team of colleagues led by Professor Paul Dirks from the University of Townsville, we were collectively able to provide an age of 1.95-1.78 million years for the fossils," Dr Pickering says.

"This is the first time, in relation to these renowned caves in South Africa, that we have been able to achieve such high-quality age control."

"Knowing how old these early human (hominin) fossils are, is critical to our knowledge of where this newly found species fits into our family tree," she says.

Associate Professor Jon Woodhead, who heads the Isotope Geosciences laboratory in the School of Earth Sciences at the University of Melbourne, noted "This is a highly significant find and I congratulate Robyn and her colleagues on their discovery."

"Only very recently have we been able to develop the technologies required to allow precise dating of cave sediments such as those found in intimate association with these new fossils."

"This really is the beginning of a 'new era' as such methods have much to contribute to studies of global climate change, biodiversity and, in this case, human evolution."

"The University of Melbourne is a world leader in this area and we are proud to have been able to contribute to this important discovery."

University of Melbourne

Stone Age Scandinavians unable to digest milk

2010-04-06T11:15:00.000+02:00

The hunter-gatherers who inhabited the southern coast of Scandinavia 4,000 years ago were lactose intolerant. This has been shown by a new study carried out by researchers at Uppsala University and Stockholm University. The study, which has been published in the journal BMC Evolutionary Biology, supports the researchers' earlier conclusion that today's Scandinavians are not descended from the Stone Age people in question but from a group that arrived later. "This group of hunter-gatherers differed significantly from modern Swedes in terms of the DNA sequence that we generally associate with a capacity to digest lactose into adulthood," says Anna Linderholm, formerly of the Archaeological Research Laboratory, Stockholm University, presently at University College Cork, Ireland.

According to the researchers, two possible explanations exist for the DNA differences.

"One possibility is that these differences are evidence of a powerful selection process, through which the Stone Age hunter-gatherers' genes were lost due to some significant advantage associated with the capacity to digest milk," says Anna Linderholm. "The other possibility is that we simply are not descended from this group of Stone Age people."

The capacity to consume unprocessed milk into adulthood is regarded as having been of great significance for human prehistory.

"This capacity is closely associated with the transition from hunter-gatherer to agricultural societies," says Anders Götherström of the Department of Evolutionary Biology at Uppsala University.

He serves as coordinator of LeCHE (Lactase persistence and the early Cultural History of Europe), an EU-funded research project focusing on the significance of milk for European prehistory.

"In the present case, we are inclined to believe that the findings are indicative of what we call "gene flow," in other words, migration to the region at some later time of some new group of people, with whom we are genetically similar," he says. "This accords with the results of previous studies."

The researchers' current work involves investigating the genetic makeup of the earliest agriculturalists in Scandinavia, with an eye to potential answers to questions about our ancestors.

Uppsala University

An archaeological mystery in a half-ton lead coffin

2010-04-01T09:09:00.002+02:00

In the ruins of a city that was once Rome's neighbor, archaeologists last summer found a 1,000-pound lead coffin. Who or what is inside is still a mystery, said Nicola Terrenato, the University of Michigan professor of classical studies who leads the project---the largest American dig in Italy in the past 50 years.

The sarcophagus will soon be transported to the American Academy in Rome, where engineers will use heating techniques and tiny cameras in an effort to gain insights about the contents without breaking the coffin itself.

"We're very excited about this find," Terrenato said. "Romans as a rule were not buried in coffins to begin with and when they did use coffins, they were mostly wooden. There are only a handful of other examples from Italy of lead coffins from this age---the second, third or fourth century A.D. We know of virtually no others in this region."

This one is especially unusual because of its size.

"It's a sheet of lead folded onto itself an inch thick," he said. "A thousand pounds of metal is an enormous amount of wealth in this era. To waste so much of it in a burial is pretty unusual."

Was the deceased a soldier? A gladiator? A bishop? All are possibilities, some more remote than others, Terrenato said. Researchers will do their best to examine the bones and any "grave goods" or Christian symbols inside the container in an effort to make a determination.

"It's hard to predict what's inside, because it's the only example of its kind in the area," Terrenato said. "I'm trying to keep my hopes within reason."

Human remains encased in lead coffins tend to be well preserved, if difficult to get to. Researchers want to avoid breaking into the coffin. The amount of force necessary to break through the lead would likely damage the contents. Instead, they will first use thermography and endoscopy. Thermography involves heating the coffin by a few degrees and monitoring the thermal response. Bones and any artifacts buried with them would have different thermal responses, Terrenato said. Endoscopy involves inserting a small camera into the coffin. But how well that works depends on how much dirt has found its way into the container over the centuries.

If these approaches fail, the researchers could turn to an MRI scan---an expensive option that would involve hauling the half-ton casket to a hospital.

The dig that unearthed this find started in summer 2009 and continues through 2013. Each year, around 75 researchers from around the nation and world, including a dozen U-M undergraduate students, spend two months on the project at the ancient city of Gabii (pronounced "gabby").

The site of Gabii, situated on undeveloped land 11 miles east of Rome in modern-day Lazio, was a major city that pre-dates Rome but seems to have waned as the Roman Empire grew.

Studying Gabii gives researchers a glimpse into pre-Roman life and offers clues to how early Italian cities formed. It also allows them broader access to more substantial archaeological layers or strata. In Rome, layers of civilization were built on top of each other, and archaeologists are not able or allowed to disturb them.

"In Rome, so often, there's something in the way, so we have to get lucky," Terrenato said. "In Gabii, they should all be lucky spots because there's nothing in the way."

Indeed, Terrenato and others were surprised to find something as significant as this coffin so soon.

"The finding of the lead coffin was exhilarating," said Allison Zarbo, a senior art history major who graduates this spring.

Zarbo didn't mind that after the researchers dug up the coffin once, they had to pile the dirt back on to hide it from looters overnight.

"The fact that we had to fill the hole was not so much of a burden as a relief!" Zarbo said. "For academia to lose priceless artifacts that have been found fully in context would be very damaging to our potential knowledge."

Students spent most of their time pick-axing, shoveling, and manning the wheelbarrows, said Bailey Benson, a junior who is double majoring in classical archaeology and art history.

"By the end of the day, not even a 20-minute shower can remove all the dirt and grime you get covered in," Benson said. "It's hard but satisfying work. How many people can say they uncovered an ancient burial?"

University of Michigan

Ancient snakes living on Madagascar

2010-03-31T10:32:00.002+02:00

"Blindsnakes are not very pretty, are rarely noticed, and are often mistaken for earthworms," admits Blair Hedges, professor of biology at Penn State University. "Nonetheless, they tell a very interesting evolutionary story." Hedges and Nicolas Vidal, of the Muséum National d'Histoire Naturelle in Paris, are co-leaders of the team that discovered that blindsnakes are one of the few groups of organisms that inhabited Madagascar when it broke from India about 100 million years ago and are still living today. The results of their study will be published in the 31 March 2010 issue of the Royal Society journal Biology Letters. Blindsnakes comprise about 260 different species and form the largest group of the world's worm-like snakes -- scolecophidians. These burrowing animals typically are found in southern continents and tropical islands, but occur on all continents except Antarctica. They have reduced vision -- which is why they are called "blind" -- and they feed on social insects including termites and ants. Because there are almost no known fossil blindsnakes, their evolution has been difficult to piece together. Also, because of their underground lifestyle, scientists have long wondered how they managed to spread from continent to continent.

In this study, the team investigated the evolution of blindsnakes by examining the genetics of living species. They extracted five nuclear genes, which code for proteins, from 96 different species of worm-like snakes to reconstruct the branching pattern of their evolution and allow the team to estimate the times of divergence of different lineages within blindsnakes using molecular clocks. "Our findings show that continental drift had a huge impact on blindsnake evolution," explains Vidal, "by separating populations from each other as continents moved apart."

Mutations in the genes record the history of these blurry-eyed serpents. The genetic research reveals that the original stock of worm-like snakes arose on Gondwana, the ancient southern supercontinent. The initial split occurred about 155 million years ago as Gondwana divided into East Gondwana (the landmasses of Antarctica, India, Madagascar, and Australia) and West Gondwana (the landmasses of South America and Africa). The residents of East Gondwana -- the blindsnakes -- then diverged into several lineages including a new family named in this study and found only on Madagascar. Later, East Gondwana further divided into a new paleolandmass -- called by the researchers "Indigascar" (India plus Madagascar) -- and another comprised of Australia and Antarctica. The research suggests that the new family on Madagascar arose as a result of the break-up of the Indigascar landmass about 94 million years ago.

Madagascar's long isolation has led to the evolution of many unique endemic animals including this family of blindsnakes, various lemurs, and other rare mammals. Unfortunately, both the animals and plants of Madagascar are now endangered by habitat loss. Says team member Miguel Vences, a professor at the Technical University of Braunschweig, Germany, and authority on the biodiversity of Madagascar, "Finding such ancient roots for a group of animals in Madagascar gives us even more reason to protect their rapidly declining habitat."

If blindsnakes got their start on Indigascar, leaving an endemic living family as evidence on Madagascar, how did they get to all of those other places in the world that they occupy today -- Europe, Asia, Australia, Africa, and the Americas?

The phylogeny constructed by the Hedges and Vidal team shows a series of diversifications within the blindsnakes, outside of Madagascar, that occurred between 63 and 59 million years ago. The period of greatest diversification coincided with a time of low sea levels, when connections between continents were forming and the dispersal of such unlikely animals by floating on flotsam was easier. Blindsnakes must have moved either out of Africa via Europe and Asia -- the ancient northern supercontinent Laurasia -- or out of India and then from southeast Asia to Australia at about 28 million years ago. Since there were no land connections between Asia and Australia at this time, these blindsnakes could have reached Australia only by crossing the ocean on floating flotsam. After that point, the splits within the blindsnakes probably occurred because they were following the evolution and spread of their prey -- ants and termites -- in various geographic regions.

Floating across oceans seems an unlikely mechanism for a burrowing animal to spread to new continents, but there is a second instance of ocean crossing by blindsnakes among the groups left on West Gondwana: West Gondwana broke up about 100 million years ago, making Africa and South America separate continents, but the genetic split between African and South American blindsnakes occurred only at about 63 million years ago. This finding shows that blindsnakes probably were confined to Africa when West Gondwana broke up and only later traveled to South America -- and still later to the West Indies -- by floating across the Atlantic from east to west.

This journey has rarely been documented. Only six or seven other vertebrates are thought to have crossed the Atlantic in a westward direction. However, the crossing would have taken no more than six months and might not have been too difficult for blindsnakes, which have a relatively low need for food and may have been floating on vegetation rafts along with their insect prey.

"Some scientists have argued that oceanic dispersal is an unlikely way for burrowing organisms to become distributed around the world," observes Hedges. "Our data now reinforce the message that such 'unlikely' events nonetheless happened in evolutionary history."

Penn State

Ancient doorway to afterlife discovered in Egypt

2010-03-30T09:56:00.001+02:00

A large red granite false door from the tomb of an ancient queen's powerful vizier has been discovered in Luxor, Egypt's culture minister said on Monday.

The carved stone door -- which ancient Egyptians believed was the threshold to the afterlife -- was unearthed near the Karnak Temple in Luxor and belongs to the tomb of User, a powerful advisor to the 18th dynasty Queen Hatshepsut, Faruk Hosni said in a statement.

The door, 1.75 metres (5.7 feet) high and 50 cm (19 inches) thick, is engraved with religious texts and various titles used by User, including mayor of the city, vizier and prince, antiquities chief Zahi Hawass was quoted as saying.

"The newly discovered door was reused during the Roman period. It was removed from the tomb of User and used in the wall of a Roman structure," said Mansur Boraik, who headed the excavation mission.

Hatshepsut, who ruled Egypt between 1479 BC and 1458 BC, was the longest reigning female pharaoh.

QMI

Scientists find first ever southern tyrannosaur dinosaur

2010-03-29T09:58:00.001+02:00

Scientists from Cambridge, London and Melbourne have found the first ever evidence that tyrannosaur dinosaurs existed in the southern continents. They identified a hip bone found at Dinosaur Cove in Victoria, Australia as belonging to an ancestor of Tyrannosaurus rex. The find sheds new light on the evolutionary history of this group of dinosaurs. It also raises the crucial question of why it was only in the north that tyrannosaurs evolved into the giant predators like T. rex.

The 30cm-long pubis bone from Dinosaur Cove looks like a rod with two expanded ends, one of which is flattened and connects to the hip and the other looks like a 'boot'.

According to Dr Roger Benson of the Department of Earth Sciences at the University of Cambridge, who identified the find: "The bone is unambiguously identifiable as a tyrannosaur because these dinosaurs have very distinctive hip bones."

The discovery lays to rest the belief held by some scientists that tyrannosaurs never made it to the southern continents.

"This is an exciting discovery because tyrannosaur fossils had only ever been found in the northern hemisphere before and some scientists thought tyrannosaurs never made it down south.

"Although we only have one bone, it shows that 110 million years ago small tyrannosaurs like ours might have been found worldwide. This find has major significance for our knowledge of how this group of dinosaurs evolved." says Dr Benson.

Dr Paul Barrett, Palaeontologist at the Natural History Museum, London and member of the research team commented: "The absence of tyrannosauroids from the southern continents was becoming more and more anomalous as representatives of other 'northern' dinosaur groups started to show up in the south. This find shows that tyrannosauroids were able to reach these areas early in their evolutionary history and also hints at the possibility that others remain to be discovered in Africa, South America and India."

The bone would have come from an animal about three metres long and weighing around 80 kg, similar to a human, and would have had the large head and small arms that make tyrannosaurs so distinctive.

The newly identified dinosaur, known as NMV P186069, was much smaller than T. rex, which was 12 metres long and weighed around four tonnes. Giant size like this only evolved late in the tyrannosaur lineage.

Compared with T. rex, which lived about 70 million years ago at the end of Cretaceous period, NMV P186069 lived earlier during the Cretaceous, around 110 million years ago.

During the time of the dinosaurs the continents gradually went from a single supercontinent towards something like their present-day arrangement. This tyrannosaur is from the mid-stages of this continental break-up, when the southern continents of South America, Antarctica, Africa and Australia had separated from the northern continents, but had not separated from each other.

While answering the question of whether or not tyrannosaurs lived in both the southern and northern hemispheres, the new find leaves another, deeper mystery: why did tyrannosaurs evolve into giant predators such as T. rex only in the northern hemisphere?

According to Dr Benson: "It is difficult to explain why different groups succeeded in the north and the south if they originally existed in both places. What we need to know now is just how diverse the early radiation of tyrannosaurs was, why they went extinct, leaving only giant-sized, short-armed species like T. rex, and how successful they might have been in the southern hemisphere. We can only answer these questions with new discoveries."

The paper is published today in Science.

University of Cambridge

A new fossil species found in Spain

2010-03-26T07:20:00.002+01:00

In the '80s, Spanish researchers found the first fossils of Cloudina in Spain, a small fossil of tubular appearance and one of the first animals that developed an external skeleton between 550 and 543 million years ago. Now palaeontologists from the University of Extremadura have discovered a new species, Cloudina carinata, the fossil of which has preserved its tridimensional shape. "Cloudina carinata is characterised by its elaborate ornamentation and complexity of the shells and tube that are formed when inserted", Iván Cortijo, main author and researcher in the Area of Palaeontology at the University of Extremadura, describes to SINC.

The study, which was recently published in Precambrian Research, describes various specimens of the new species. These fossils show evidence of asexual reproduction, until now "only described in Chinese specimens of Cloudina", and are "one of the oldest examples of reproduction in animals in the fossil register", maintains the researcher from Extremadura.

The fossils have been found in the archaeological site El Membrillar (Badajoz), one of the few sites in Europe where remains of Cloudina can be found. "The specimens display exceptional preservation, they appear preserved in three dimensions, and show their original form and numerous details of the shells", Cortijo points out.

The discovery of new species of Cloudina is important "for understanding the early evolution of animals", states Cortijo, who adds that "its importance for understanding the origin of skeletons is indisputable". Despite the fact that its relation to other groups of animals is uncertain, Cloudina has been compared to cnidaria (medusas and corals) and annelida (polychaeta sea worms, earthworms and leeches).

According to the research team, the study of fossils from the Ediacaran period (between 630 and 540 million years ago) and of other fossils from the early Cambrian (540 million years ago) reveals the path followed by evolution at a crucial moment in the history of life, when the first animals appeared. This first evolutionary radiation of animals reached its apex in the so-called "great Cambrian explosion" or "Big-Bang of evolution".

In search of Cloudina

In the '70s specimens of Cloudina were discovered for the first time in Namibia and later they were discovered in Oman, southern China and the south-east of the USA. According to scientists, it is a fossil indicative of the terminal Ediacaran, which marks the end of the Proterozoic eon, and gives way to the Phanerozoic, when the great radiation of animals began.

In Spain Cloudina was discovered in the '80s thanks to Teodoro Palacios, director of the research group Palaeontology and Stratigraphy of the Neoproterozoic and Palaeozoic at the University of Extremadura.

FECYT - Spanish Foundation for Science and Technology

New ancestor? Scientists ponder DNA from Siberia

2010-03-25T07:23:00.002+01:00

In the latest use of DNA to investigate the story of humankind, scientists have decoded genetic material from an unidentified human ancestor that lived in Siberia and concluded it might be a new member of the human family tree.

The DNA doesn't match modern humans or Neanderthals, two species that lived in that area around the same time — 30,000 to 50,000 years ago.

Instead, it suggests the Siberian species lineage split off from the branch leading to moderns and Neanderthals a million years ago, the researchers calculated. And they said that doesn't seem to match the history of human ancestors previously known from fossils.

So the Siberian species may be brand new, although the scientists cautioned that they're not ready to make that claim yet.

Other experts agreed that while the Siberian species may be new, the case is far from proven.

"We really don't know," said Ian Tattersall of the American Museum of Natural History in New York, who wasn't involved in the new research.

But "the human family tree has got a lot of branchings. It's entirely plausible there are a lot of branches out there we don't know about."

The discovery "is like many new finds," said Eric Delson of Lehman College of the City University of New York, who didn't participate in the new work. "You say, `I think this is different, but I'm not sure.' And then you look for more material and you try to make better comparisons."

The researchers, who say the Siberian species is not a direct ancestor of modern-day people, hope further genetic analysis will show if it's a new species. Some experts are skeptical about whether such analysis will resolve that.

In any case, the finding emphasizes that quite unlike the present day, anatomically modern humans have often lived alongside their evolutionary relatives, one expert said.

"We weren't alone," said Todd Disotell of New York University, who was familiar with the new work. "When we became modern, we didn't instantly replace everybody. There were other guys running around who survived quite well until very, very recently."

Just last month, other researchers used DNA analysis to show the genetic diversity still present in residents of Africa, the cradle of the human race. And another project produced the first genome of an ancient human — a man who lived in Greenland some 4,000 years ago.

The new work, published online Wednesday by the journal Nature, is reported by Johannes Krause and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and others.

They describe mapping DNA from what appeared to be a youngster's pinkie finger bone, which had been recovered in 2008 from Denisova Cave in Altai Mountains of southern Siberia. They showed how it differed from DNA of 54 modern-day people and six Neanderthals.

Their analysis indicated the Siberian species last shared a common ancestor with modern humans and Neanderthals about 1 million years ago. That in turn suggested there was a previously unrecognized migration out of Africa around that time, they said.

The work decoded the complete set of DNA from mitochondria, the power plants of cells. That's different from the better-known DNA that comes from cell nuclei and determines things like eye color. Paabo said the researchers are working to decode nuclear DNA from the Siberian species. That will reveal whether it was closely related to Neanderthals or today's humans, and answer questions like whether it interbred with Neanderthals or ancestors of modern-day people, he said.

Without a completed analysis of the nuclear DNA, "we are not saying this is a new species," Paabo said, although he said that's a likely possibility.

Rick Potts, director of the Smithsonian Institution's Human Origins Program, said the Siberian find might represent Homo heidelbergensis or Homo erectus. And even analysis of the Siberian species' nuclear DNA won't show if it's distinct from those ancestors, he said.

As for the study's suggestion of a migration out of Africa about a million years ago, Potts said there's already evidence of one or two migrations around that time.

The finger bone recovered from the Siberian species is not enough for a fossil-to-fossil comparison with other ancient species to show whether it's a new species, Delson said.

He suspects it might be a descendant of Homo erectus that's already documented in some fossil remains in northern Africa and Europe. Scientists are still trying to figure out how many species of the Homo grouping those bones represent and what name or names to attach to them, he said.

Disotell said the new creature could be an early version of Homo antecessor, a forerunner of Neanderthals and modern humans known from fossils in Spain. Or, he said, it could be a new species. In fact, the eventual decision could hinge mostly on the philosophical question of just how different a creature has to be to be declared a new species, he said.

Potts said that in the new work, "what we're seeing is a really, really interesting distant echo of the DNA history of human evolution.... This is an amazingly powerful technique that these guys have. This is going to be a growth industry in the study of human evolution."

MIA

New dinosaur species found in Utah sandstone

2010-03-24T07:21:00.002+01:00

A new species of dinosaur has emerged from the rocks of southern Utah.

Buried by a collapsing sand dune, perhaps 185 million years ago, the new dino was probably a plant eater and an early relative of the giant animals later known as sauropods, researchers report in Tuesday's edition of the journal PLoS One.

Named Seitaad ruessi, the species was 10-to-15 feet long and 3-to-4 feet high. It's bones were found protruding from sandstone at the base of a cliff, directly below an ancient Anasazi cliff dwelling.

No humans were around at the time of the dinosaurs, but researchers say the bones could well have been visible when the early Indians lived there.

The name Seitaad comes from the word "Seit'aad," which was a sand monster that buried its victims in dunes in Navajo legend, according to the researchers. The newly named skeleton had been swallowed by a sand dune.

So, might visible dinosaur remains have given rise to the ancient Indian monster legend?

"That's a lot of speculation, but anything's possible," said Mark Loewen, a paleontologist at the Utah Museum of Natural History and instructor in the Department of Geology and Geophysics at the University of Utah.

One of the Anasazi dwellings included a stone with a dinosaur footprint in its center, he noted.

The ruessi part of the name is in honor of poet and naturalist Everett Ruess who disappeared in southern Utah in 1934.

Understanding how dinosaurs lived in the past, how their environments changed and affected them, is important for understanding our changing world today, Loewen said.

The nearly complete skeleton is missing only its head, one toe and a lower shinbone, he said, noting erosion over the years probably accounts for the missing parts.

What the researchers have is similar to other sauropodomorphs found in South America and southern Africa, which were all vegetarians, he explained in a telephone interview. However, Seitaad did have a claw on its front limbs, which Loewen suggested was probably used for defense.

"We were absolutely shocked" by the discovery of this dinosaur, Loewen said. It was found in 2004 by a local artist studying rock paintings and the scientists went to the area immediately when they learned of it, he said. The bones were excavated the following year by Museum researchers.

While dinosaur remains have been found in other parts of Utah fossils are rare in the Navajo sandstone areas and generally have been from smaller creatures.

"This new find suggests that there may be more dinosaurs yet to be discovered in these rocks," said Joseph Sertich, co-author of the report and currently a doctoral student at New York's Stony Brook University.

news.yahoo.com

University of Kansas researcher investigates mysterious stone spheres in Costa Rica

2010-03-23T07:22:00.002+01:00

The ancient stone spheres of Costa Rica were made world-famous by the opening sequence of "Raiders of the Lost Ark," when a mockup of one of the mysterious relics nearly crushed Indiana Jones. So perhaps John Hoopes is the closest thing at the University of Kansas to the movie action hero.

Hoopes, associate professor of anthropology and director of the Global Indigenous Nations Studies Program, recently returned from a trip to Costa Rica where he and colleagues evaluated the stone balls for UNESCO, the United Nations cultural organization that might grant the spheres World Heritage Status.

His report will help determine if sites linked to the massive orbs will be designated for preservation and promotion because of their "outstanding value to humanity."

Hoopes, who researches ancient cultures of Central and South America, is one of the world's foremost experts on the Costa Rican spheres. He explained that although the stone spheres are very old, international interest in them is still growing.

"The earliest reports of the stones come from the late 19th century, but they weren't really reported scientifically until the 1930s — so they're a relatively recent discovery," Hoopes said. "They remained unknown until the United Fruit Company began clearing land for banana plantations in southern Costa Rica."

According to Hoopes, around 300 balls are known to exist, with the largest weighing 16 tons and measuring eight feet in diameter. Many of these are clustered in Costa Rica's Diquis Delta region. Some remain pristine in the original places of discovery, but many others have been relocated or damaged due to erosion, fires and vandalism.

The KU researcher said that scientists believe the stones were first created around 600 A.D., with most dating to after 1,000 A.D. but before the Spanish conquest.

"We date the spheres by pottery styles and radiocarbon dates associated with archeological deposits found with the stone spheres," Hoopes said. "One of the problems with this methodology is that it tells you the latest use of the sphere but it doesn't tell you when it was made. These objects can be used for centuries and are still sitting where they are after a thousand years. So it's very difficult to say exactly when they were made."

Speculation and pseudoscience have plagued general understanding of the stone spheres. For instance, publications have claimed that the balls are associated with the "lost" continent of Atlantis. Others have asserted that the balls are navigational aids or relics related to Stonehenge or the massive heads on Easter Island.

"Myths are really based on a lot of very rampant speculation about imaginary ancient civilizations or visits from extraterrestrials," Hoopes said.

In reality, archaeological excavations in the 1940s found the stone balls to be linked with pottery and materials typical of pre-Columbian cultures of southern Costa Rica.

"We really don't know why they were made," Hoopes said. "The people who made them didn't leave any written records. We're left to archeological data to try to reconstruct the context. The culture of the people who made them became extinct shortly after the Spanish conquest. So, there are no myths or legends or other stories that are told by the indigenous people of Costa Rica about why they made these spheres."

Hoopes has a created a popular Web page to knock down some of the misconceptions about the spheres. He said the stones' creation, while vague, certainly had nothing to do with lost cities or space ships.

"We think the main technique that was used was pecking and grinding and hammering with stones," said Hoopes. "There are some spheres that have been found that still have the marks of the blows on them from hammer stones. We think that that's how they were formed, by hammering on big rocks and sculpting them into a spherical shape."

University of Kansas

Students discover new species of raptor dinosaur

2010-03-19T11:12:00.001+01:00

A new species of dinosaur, a relative of the famous Velociraptor, has been discovered in Inner Mongolia by two PhD students. The exceptionally well preserved dinosaur, named Linheraptor exquisitus, is the first near complete skeleton of its kind to be found in the Gobi desert since 1972, and will help scientists work out the appearance of other closely related dinosaur species.

Linheraptor is in the Dromaeosauridae family of the carnivorous theropod dinosaurs and lived during the Late Cretaceous period. In addition to Linheraptor and Velociraptor, theropod dinosaurs include charismatic meat-eaters like Tyrannosaurus rex and modern birds.

The two PhD students, Michael Pittman from UCL (University College London) and Jonah Choiniere from George Washington University (GWU), found the dinosaur sticking out of a cliff face during a field project in Inner Mongolia, China. Their research is published online today in the journal Zootaxa.

"Jonah saw a claw protruding from the cliff face. He carefully removed it and handed it to me. We went through its features silently but he wanted my identification first. I told him it was from a carnivorous dinosaur and when he agreed I'm surprised nobody in London heard us shouting," said Michael Pittman, a PhD student in the UCL Department of Earth Sciences who was the co-discoverer of the dinosaur.

"I've always wanted to discover a dinosaur since I was a kid, and I've never given up on the idea. It was amazing that my first discovery was from a Velociraptor relative. My thesis is on the evolution and biomechanics of dinosaur tails but the carnivorous dinosaurs are my favourite and my specialty," he added.

At approximately 2.5 metres long and 25 kilograms, the researchers believe Linheraptor would have been a fast, agile predator that preyed on small horned dinosaurs related to Triceratops. Like other dromaeosaurids, it possessed a large "killing claw" on the foot, which may have been used to capture prey. Within the Dromaeosauridae family, Linheraptor is most closely related to another recently discovered species Tsaagan mangas.

Linheraptor differs from all other dromaeosaurs because of a triangular hole in front of the eye socket called the antorbital fenestra, which is a space in the skull that sinuses would have occupied. In Linheraptor this triangular hole is divided into two cavities – one of which is particularly big.

"This is a really beautiful fossil and it documents a transitional stage in dromaeosaurid evolution," said Dr. Xu Xing, Professor of Palaeontology at the Institute of Vertebrate Paleontology & Paleoanthropology (IVPP).

Linheraptor was found in rocks of the Wulansuhai Formation, part of a group of red sandstone rocks found in Inner Mongolia, China during a field expedition by the researchers in 2008. It is the fifth dromaeosaurid discovered in these rocks, which are famous for their preservation of uncrushed, complete skeletons.

The research was done as part of the Inner Mongolia Research project, led by Dr. Xu, which aims to better understand the Late Cretaceous ecosystem of Inner Mongolia, China which is analogous but less well-studied than the well known Late Cretaceous ecosytem of Outer Mongolia. The research was funded by the Geological Society of London, the US National Science Foundation, the Chinese National Science Foundation, and George Washington University.

University College London

A blue mystery

2010-03-18T11:00:00.002+01:00

Jennifer Smith, PhD, associate professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, was belly crawling her way to the end of a long, narrow tunnel carved in the rock at a desert oasis by Egyptians who lived in the time of the pharaohs. "I was crawling along when suddenly I felt stabbed in the chest," she says. "I looked down and saw that I was pressing against the broken end of a long bone. That freaked me out because at first I thought I was crawling over bodies, but I looked up and saw a sheep skull not too far away, so I calmed down. At least the bones weren't human."

What was she doing in the tunnel?

The answer: seeking an uncontaminated sample of a mineral that might have been the key ingredient in the blue used to decorate "blue painted pottery" popular among the Egyptian elite during the New Kingdom (1550 to 1079 BCE).

Colleague Colin A. Hope, an expert in blue painted pottery, had asked if she wouldn't help him pin down the source of the blue pigment by sampling and analyzing material fromt he mine.

Hope and Smith, together with Paul Kucera, a doctoral student at Monash University who first identified the mines, describe the pottery, the mines and the mineral in a chapter of Beyond the Horizon, a festschrift for the Egyptologist Barry A. Kemp

'Generic geologist'

In the wastes of the eastern Sahara, nestled against the limestone escarpment that separates the desert from the Nile Valley, lies the Dakhleh Oasis. This fortunate spot, where deep water is able to reach the surface along fractures and faults under its own pressure, has been continuously inhabited for a very long time — perhaps as long as 400,000 years.

During that period there were roughly four glacial cycles and, although Egypt itself was ice-free, the local climate oscillated from hyperarid to semi-arid as the Earth's orbital position drove changes in the location of the tropical rainfall belts.

Smith studies the impact of these climate fluctuations on ancient oasis dwellers.

But Smith is also the "generic geologist" as she puts it, for the Dakhleh Oasis Project, a long-term study of the oasis that covers the entire stretch of Dakhleh history, from the Neolithic through the Pharaonic, Roman, Islamic and modern settlements, and employs — off and on — more than 50 specialists.

"The dig house is open from November until March," Smith says.

As generic geologist, Smith was asked to help with a material-sourcing puzzle that she says was "way outside her period." During the 2007 season, Colin A. Hope, PhD, associate professor and director of the Center for Archaeology and Ancient History at Monash University in Australia, asked her whether a mineral found at the oasis could have been used to color the blue painted pottery.

It was a small question but an intriguing one.

Blue painted pottery

Most Egyptian pottery is undecorated, but during the New Kingdom, the period when Egypt is at the zenith of its power, a variety of pottery was elegantly decorated in a distinctive pale blue.

The pottery has been found at many sites in Egypt, and also in the Middle East and in Sudan.

The largest deposits, however, were found at New Kingdom sites in Egypt, including Malqata (the palace complex of Amenhotep III), Amarna (the remains of the city built by the Akenaten, the famous pharaoh who moved the capital from Thebes and established his own religion), the cemetary at Deir el-Medineh (the village where artisans who worked on the tombs in the Valley of the Kings during the New Kingdom lived), and the Great Temple of Amun (patron of kingship during the New Kingdom).

"Walking over some sites, it is only a matter of minutes before several shards of blue painted pottery or cobalt blue glass or faience can be collected," Hope, who has written extensively about the pottery, says.

Given the restricted use to which the pigment was put and the archeological sites where remnants were found, Hope believes it was probably available only to artisans associated with major royal residences.

The pale blue is distinguishable at a glance from the brilliant blues and blue-greens of the faience glazes common from the 3000 BC onward. Faience, probably most familiar in the form of the small statue of a hippo nicknamed William that is now in the collection of the Metropolitan Museum of Art in New York, was made by adding ground copper to ground quartz to create what ceramists today call Egyptian paste.

But it is difficult to create durable patterns with copper pigment on pottery, says Hope. "Copper-based pigments must be applied in thick layers and were added after firing, so they tended to flake off when an object was handled. Instead of copper, the colorant used on most of the blue painted pottery is cobalt, which was fired onto the pots.

Where did the cobalt-bearing mineral come from? Analysis of the paint showed that the cobalt was accompanied by trace amounts of zinc, nickel and manganese, a mixture of elements distinctive enough to serve as a chemical fingerprint.

The mines of Dakhleh

At the height of its power, the Egyptian administration of the Nile Valley sponsored mineral exploitation of the Valley and surrounding desert regions. As early as 1980, it was suggested that the cobalt might have come from the desert oases at Dakhleh and Kharga.

In the lower foothills of the oasis escarpment at the western end of Dakhleh, four mine shafts were meticulously hand-cut into the rock. Steps carved along the shafts allowed a safe descent. The shafts provided access to horizontal galleries, some as long as 15 meters, that followed horizontal veins of the mineral alum.

A few centimeters thick, the alum veins are fibrous, pale gray to pink in color and slightly astringent.

Alum is both the term for a specific compound and for a class of compounds, all of which contain two negatively charged sulfate groups and two chemical elements or groups bearing a positive charge. The specific compound is hydrated aluminum potassium sulfate but many other elements or groups can substitute for the aluminum and potassium, and cobalt is one of these.

Alum was probably exploited for a variety of purposes in ancient times, some having nothing to do with color. The Egyptians, for example, used alum both to whiten skins during tanning and to prepare cloth to absorb dye.

Alum is still used today in styptic pencils to stem bleeding and in recipes for pickling cucumbers. More recently, it has been in vogue as a "crystal deodorant" that is sold as more natural than older deodorant products.

Was the Dakhleh Oasis alum used as a general-purpose astringent, or did it have the same chemical fingerprint as the blue paint on the pottery?

Analyzing the alum

To find out, Smith needed to sample the alum and analyze its composition.

"I wanted to get relatively unaltered samples," she says, "which is why I was crawling to the end of a gallery. The galleries were small enough you couldn't really crawl on your hand and knees: you had to belly crawl."

Smith brought the samples she collected back to Washington University where she ran them through a variety of sophisticated analytical instruments. "When we characterize a natural mineral," she says, "we want to know two things: its chemical composition and then how the elements that make it up are arranged, or its crystal structure."

In the case of the Dakhleh alum, the crystal structure was of little use because it would have been destroyed in preparing the paint. Only the composition could connect the alum to the pottery.

Smith's results showed that the alum did contain cobalt, although they weren't particularly rich in this element. The cobalt, however, was accompanied by trace amounts of manganese, nickel and zinc, the same mixture of elements found in the blue paint.

Surprised by the low concentration of cobalt, Smith wondered if the ancient artisans hadn't found a way to concentrate it on site. One sample she collected, a crust at the edge of a partially flooded mine shaft, had a higher cobalt content than the others. Because sulphate dissolves easily and the mines were much more likely to have been flooded in the past, she wondered whether the cobalt was mined not by chipping it out of the rock but instead by ladling water out of the mines and collecting the sediment left over when the water evaporated.

"But this is wild arm waving given the amount of data," Smith says.

This small exercise in archeological problem solving left her with a deep respect for the long-vanished miners.

"I look at all these different veins of sulfate and I don't know which are useful for which purposes without doing analyses, but they must have had ways of telling from observable properties which ones to mine. That's impressive," she says.

Washington University in St. Louis

3,400-Year-Old Statues Unearthed in Egypt

2010-03-17T09:08:00.001+01:00

Large Granite Statues Depicting God of Wisdom and Pharaoh Amenhotep III Found at Recently-Discovered Mortuary Temple.

A team of archaeologists unearthed two large red granite statues in southern Egypt at the mortuary temple of one of the most powerful pharaohs, who ruled nearly 3,400 years ago, the Culture Ministry said Tuesday.

A ministry statement said the team discovered a 13-foot statue of Thoth, the ancient god of wisdom, and the top part of a statue of Pharaoh Amenhotep III standing next to another god.

Both were found buried in the pharaoh's mortuary temple on the west bank of the Nile in the southern temple city of Luxor.

On Feb. 28, archaeologists discovered a massive red granite head of Amenhotep III at the same temple. The head, which is about the height of a person, is the best preserved sculpture of Amenhotep III's face found to date.

Amenhotep III, who was the grandfather of the famed boy-pharaoh Tutankhamun, ruled from 1387-1348 B.C. at the height of Egypt's New Kingdom and presided over a vast empire stretching from Nubia in the south to Syria in the north.

The temple was largely destroyed, possibly by floods, and little remains of its walls.

But archaeologists have been able to unearth a wealth of artifacts and statuary in the buried ruins, including two statues of Amenhotep made of black granite found in March 2009.

Egyptian Ministry of Culture

Rare armor-plated creature discovered in Canada's capital

2010-03-17T09:06:00.001+01:00

Scientists have unearthed the remains of one of the Worlds rarest fossils - in downtown Ottawa. The 450 million year old fossil preserves the complete skeleton of a plumulitid machaeridian, one of only 8 such specimens known. Plumulitids were annelid worms - the group including earthworms, bristleworms and leeches, today found everywhere from the deepest sea to the soil in your yard - and although plumulitids were small they reveal important evidence of how this major group of organisms evolved. "Such significant new fossils are generally discovered in remote or little studied areas of the globe, requiring difficult journeys and a bit of adventure to reach them" notes Jakob Vinther of Yale University, lead author of the paper describing the specimen. "Not this one though. It was found in a place that has an address rather than map co-ordinates!"

Plumulites canadensis, Albert Street, Ottawa, Canada K1P1A4. The fossil is described by Vinther and Dave Rudkin, of Toronto's Royal Ontario Museum, in the current issue of the journal Palaeontology.

It was Rudkin who first recognised its scientific significance: "This nifty little specimen first came to my notice when I received a letter from an amateur fossil collector in Nepean, Ontario. In prospecting for fossils in rock from a temporary building excavation he had turned up a small block containing a complete trilobite, but next to it was something else and he sent me a slightly fuzzy but very intriguing photo. The mystery fossil was clearly not another trilobite, and I although couldn't be certain, I thought it might be some sort of annelid worm with broad, flattened scales. James, the collector, generously agreed to lend me the specimen and I realised immediately it was a complete, fully articulated machaeridian! The first I had ever seen."

At that time it was not known that machaeridians were annelids. "James was happy to donate the specimen to the Royal Ontario Museum, in exchange for a promise that I'd someday publish his discovery."

It was not until 2008 that Rudkin's hunch was confirmed, when a team of palaeontologists, including Jakob Vinther, decribed new machaeridian fossils from remote mountain localities in Morocco, revealing their relationship to annelid worms. Rudkin and Vinther agreed to work together to interpret the Ottawa specimen, and it is the results of that collaboration that are published in the current Palaeontology.

Plumulitid machaeridians look like modern bristleworms, with stout walking limbs bearing long bundles of bristles, but on their back they carried a set of mineralized plates. According to Vinther, "the plates themselves were rigid, but they could move relative to one other, providing plumulitids with a protective body armour very similar to the flexible metal armour invented by humans 450 million years later. Machaeridian body armour is unique among annelids, and probably helped them to succeed as ubiquitous components of marine ecosystems for more than 200 million years."

With the publication of this paper Rudkin is finally able to make good on his promise "It's great to be able to acknowledge the collector", says Rudkin, but there is a twist to this tale: the man who found the specimen has now gone missing. "Regrettably, I lost contact with James and numerous enquiries as to his whereabouts have come up empty. I hope he somehow gets wind of all this."

Wiley-Blackwell

Pottery leads to discovery of peace-seeking women in American Southwest

2010-03-12T10:02:00.000+01:00

From the time of the Crusades to the modern day, war refugees have struggled to integrate into their new communities. They are often economically impoverished and socially isolated, which results in increased conflict, systematic violence and warfare, within and between communities as the new immigrants interact with and compete with the previously established inhabitants. Now, University of Missouri researcher Todd VanPool believes pottery found throughout the North American Southwest comes from a religion of peace-seeking women in the violent, 13th-century American Southwest. These women sought to find a way to integrate newly immigrating refugees and prevent the spread of warfare that decimated communities to the north. First discovered in 1930's Arizona, Salado pottery created a debate among archaeologists. According to VanPool, the Salado tradition is a grassroots movement against violence. The mystery of the pottery's origin and significance was known as "the Salado problem." This southwestern pottery was found among three major cultural areas of the ancient southwest: the ancestral Puebloan in northern Arizona and New Mexico, the Mogollon of southern New Mexico and the Hohokam of central and southern Arizona, all with different religious traditions. Even though the pottery was found in three different cultural areas, the pottery communicated the same, specific set of religious messages. It was buried with both the elite and non-elite and painted with complex, geometric motifs and animals, such as horned serpents. Instead of celebrating local elites, the symbols in Salado pottery emphasized fertility and cooperation.

"In my view, the fact that the new religion is reflected solely in pottery, a craft not usually practiced by men, suggests that it was a movement that helped bring women together and decreased competition among females," said VanPool, who is an assistant professor of anthropology in the MU College of Arts and Science. "Women across the region may have been ethnically diverse, but their participation in the same religious system would have helped decrease conflict and provided a means of connecting different ethnic groups."

Salado pottery dates from the 13th to 15th centuries in which there was major political and cultural conflict in the American Southwest. Brutal executions and possible cannibalism forced thousands of people to abandon their native regions and move to areas of Arizona and New Mexico. Another source of conflict appeared after the female refugees and their children arrived in their new homelands.

"Conflict was defused through the direct action of women who sought to decrease the tensions that threatened to destroy their communities," VanPool said. "The rise of the Salado tradition allowed threatened communities to stabilize over much of modern-day Arizona and new Mexico, altering the course of Southwestern prehistory. Given that the Salado system lasted from 1275 to around 1450, it was most certainly successful."

University of Missouri-Columbia

Australian archaeologists uncover 40,000-year-old site

2010-03-11T08:45:00.003+01:00

Australian archaeologists have uncovered what they believe to be the world's southernmost site of early human life, a 40,000-year-old tribal meeting ground, an Aboriginal leader said Wednesday.

The site appears to have been the last place of refuge for Aboriginal tribes from the cannon fire of Australia's first white settlers, said Michael Mansell of the Tasmanian Aboriginal Centre.

The find came during an archaeological survey ahead of roadworks near Tasmania's Derwent River and soil dating had established the age of the artefacts found there.

"When the archaeological report came out it showed that (life there) had gone back longer than any other recorded place anywhere else in Tasmania, dating back to 40,000 years," Mansell told AFP.

Up to three million artefacts, including stone tools, shellfish fragments and food scraps, were believed to be buried in the area, which appeared to have been a meeting ground for three local tribes.

They died out after white settlers arrived in the late 18th century.

"They (settlers) hunted people here to this place and shot them just so they could get the land," said Mansell. "Many others were imprisoned until they died."

"In terms of culture and history this region now represents Tasmania's Valley of the Kings," he added, referring to the world heritage listed Egyptian tombs on the west bank of the Nile.

"When you get something like this that evokes memory of what your people did before we were born and evokes a memory about the legacy that they left us ... it makes the place irreplaceable."

The survey was finished last week and chief archaeologist Rob Paton said he had been surprised at the age of the items found.

"We haven't even done a reading on the bottom sample yet, I was expecting 17,000 (years) for the base of the trench and about 4 or 5,000 (years) for the top," Paton told state radio.

Paton said luminescence readings -- measuring the age of the artefacts based on how much exposure they had received to sunlight -- had been "nice and statistically tight".

"That suggests to me that they're probably correct, giving us a top reading of 28,000 (years old) and certainly seeming to go back another 10,000 (years) at least beyond that," he said.

The readings indicated that "we do have the oldest, most southern site anywhere in the world", said Paton, making it "an important site for anyone and quite exciting for us".

"I think the thing to stress is no matter what the age of the site it's important anyway," he added.

Mansell said the tribes were famous for their defiant stand against the settlers, and so frustrated the authorities they ultimately issued an order that any Aborigine in the area be shot on sight.

He said the dig's findings were merely the "tip of the iceberg" and called for plans to build a bridge over the site to be scrapped.

"The Tasmanian government must immediately declare it a protected site, not just for Aboriginal people but for peoples of the world," said Mansell.

Australia's original inhabitants, with cultures stretching back tens of thousands of years, are believed to have numbered around one million at the time of white settlement.

There are now just 470,000 out of a population of 21 million and Australia's most impoverished minority.

physorg.com

Half of Earth's life may lie below land, sea

2010-03-10T09:02:00.001+01:00

Scientists estimate that nearly half the living material on our planet is hidden in or beneath the ocean or in rocks, soil, tree roots, mines, oil wells, lakes and aquifers on the continents.

They call it the "subsurface biosphere," a dark world where the sun and stars don't shine. Some call it Earth's basement.

"Earth's habitable zone extends to depths of hundreds or thousands of meters," Katrina Edwards, a microbiologist at the University of Southern California, told a December conference of the American Geophysical Union in San Francisco. "The organisms that live in this environment may collectively have a mass equivalent to that of all of Earth's surface dwellers and may provide keys to solving major environmental, agricultural and industrial problems."

For example, geologists are considering whether to store some of the world's excess carbon dioxide, a major greenhouse gas, in a worldwide network of crevices below the seafloor.

Scientists say research on "intraterrestrial life" complements astronomers' hunt for "extraterrestrial life" around other stars and planets. The search for E.T. starts at home.

"Much that we do in our work to discover and understand the deep biosphere has relevance to the origin and search for life elsewhere in the universe," Edwards said by e-mail. "Fundamentally, this is all about life detection. ... Our inner space is a natural testing ground for outer space."

To advance their understanding of subsurface life, marine geologists are about to launch three drill ship expeditions to punch holes in the seafloor and implant long-term scientific "observatories" linked by cable and satellite to onshore laboratories.

"We'll be sitting in front of a fire hose of data," said Andrew Fisher, a geophysicist at the University of California in Santa Cruz.

In July, the international Integrated Ocean Drilling Program will send its high-tech drill ship, the JOIDES Resolution, to the Juan de Fuca Ridge off the Canadian coast in the Northeast Pacific. In October, the ship will head for the South Pacific Gyre, a vast rotating pool of water between New Zealand and Hawaii. Next year, it will pass through the Panama Canal to drill in North Pond, an undersea valley on the Mid-Atlantic Ridge, a chain of seamounts between North America and Africa.

Fisher, the chief scientist on the Juan de Fuca expedition, said this summer's drilling would complete a network of six observatories under the North Pacific seafloor.

Dyed fluids will be pumped into selected places so scientists can follow the flow of water and microbes through a maze of subsurface "plumbing." These deep oceanic aquifers are thought to contain as much water as all the rivers on Earth.

"It'll be like determining how your home plumbing works by sampling the water at the taps," Fisher said.

Subsurface biosphere research may shed light on the origin of life on Earth and the possibility of life on other planets.

"The conditions we see in the sub-seafloor are similar to what conditions may have been on the early Earth," Fisher said. Similar conditions may exist or have existed on Mars or the moons of Jupiter.

"It is highly likely that if Mars supports life, it will also be in a deep biosphere where temperatures are high enough to allow liquid water," John Parnell, a geologist at the University of Aberdeen, Scotland, told a conference of planetary scientists last week in The Woodlands, Texas.

Steven D'Hondt, an oceanographer at the University of Rhode Island, will lead the expedition to the South Pacific Gyre. The JOIDES Resolution will drive seven holes in the seafloor to study microbial life there.

One objective will be to determine whether deep sea chemicals, such as hydrogen and sulfur, that don't depend on energy from the sun on Earth's surface can nourish subsurface microbes.

Edwards, the USC microbiologist, expects to lead the 2011 expedition to North Pond, in the Atlantic, where four holes will be drilled. One goal is to find out whether microbes in the Atlantic are different from their Pacific Ocean cousins, or whether the same creatures travel around the globe.

McClatchy-Tribune

Khirbet Qeiyafa identified as biblical 'Neta'im'

2010-03-09T07:24:00.000+01:00

Has another mystery in the history of Israel been solved? Prof. Gershon Galil of the Department of Bible Studies at the University of Haifa has identified Khirbet Qeiyafa as "Neta'im", which is mentioned in the book of Chronicles. "The inhabitants of Neta'im were potters who worked in the king's service and inhabited an important administrative center near the border with the Philistines," explains Prof. Galil. Khirbet Qeiyafa is a provincial town in the Elah Valley region. Archaeological excavations carried out at Khirbet Qeiyafa by a team headed by Prof. Yosef Garfinkel and Mr. Saar Ganor have dated the site to the beginning of the 10th century BCE, namely the time of King David's rule. A Hebrew inscription on a pottery shard found at the site, also dating back to the 10th century, has recently been deciphered by Prof. Galil and indicates the presence of scribes and a high level of culture in the town.

The genealogy of the Tribe of Judah dated to the same period is recorded in 1 Chronicles. The last verse of this genealogy, 1 Chronicles 4:23, mentions two important cites: Gederah and Neta'im, both of which were administrative centers, since they were inhabited by people who work "in the king's service": "These were the potters, the inhabitants of Neta'im and Gederah, they dwelt there in the King's service." Gederah has been identified by A. Alt with Khirbet Ğudraya, near the Elah Valley, but Neta'im, which is mentioned only once in the Bible, remained unidentified.

American scholar Prof. William Albright, a leading archaeologist, proposed associating Neta'im with Khirbet En-Nuweiti', which is also located near the Elah Valley, based on the phonological similarity between the two names. Archaeological surveys at Khirbet En-Nuweiti', however, revealed that it was only inhabited during Hellenistic and Roman-Byzantine times, and not during the Iron Age.

Prof. Galil's identification of Khirbet Qeiyafa with Neta'im is based on the proximity of Khirbet Qeiyafa to biblical Gederah/Khirbet Ğudraya; on the archaeological findings – including impressive fortifications - dating from the time of King David's rule and indicating that this was an administrative center; and on the preserved name of nearby Khirbet En-Nuweiti'.

"The archeological findings at this site, the discovery of the earliest and most important Hebrew inscription to be found to date, and the understanding, based on the biblical text, that members of the Tribe of Judah inhabited the town and worked in the king's service, testify to Khirbet Qeiyafa – Neta'im – being an important administrative center in the border region of the Kingdom of Israel during the time of King David's reign. The existence of this fortified administrative center relatively far from the center of the kingdom testifies to a conflict that broke out between the Israelites the Philistines after David was victorious over the House of Saul and all of the Tribes of Israel were unified under his leadership. It is further proof of a large and powerful kingdom during the days of King David," Prof. Galil concludes.

University of Haifa

Utah paleontologist part of international team to discover oldest known dinosaur relative

2010-03-08T09:31:00.002+01:00

Until now, paleontologists have generally believed that the closest relatives of dinosaurs possibly looked a little smaller in size, walked on two legs and were carnivorous. However, a research team including Randall Irmis, curator of paleontology at the Utah Museum of Natural History and assistant professor in the Department of Geology and Geophysics at the University of Utah has made a recent discovery to dispel this hypothesis. The team announced the discovery of a proto-dinosaur (dinosaur-like animal) — a new species called Asilisaurus kongwe (a-SEE-lee-SOAR-us KONG-way), derived from asili (Swahili for ancestor or foundation), sauros (Greek for lizard), and kongwe (Swahili for ancient). The first bones of Asilisaurus were discovered in 2007, and it is the first proto-dinosaur recovered from the Triassic Period in Africa. Asilisaurus shares many characteristics with dinosaurs but falls just outside of the dinosaur family tree—living approximately 10 million years earlier than the oldest known dinosaurs.

The description of the new species Asilisaurus kongwe appears in the March 4 issue of the journal Nature in a paper co-authored by an international team, including Irmis, Sterling Nesbitt, a postdoctoral researcher at the University of Texas at Austin's Jackson School of Geosciences, Christian A. Sidor (Burke Museum and University of Washington), Kenneth D. Angielczyk (The Field Museum, Chicago), Roger M.H. Smith (Iziko South African Museum, South Africa), and Linda A. Tsuji (Museum für Naturkunde and Humboldt-Universität zu Berlin, Germany).

Fossil bones of at least 14 individuals were recovered from a single bone bed in southern Tanzania making it possible to reconstruct nearly the entire skeleton, except portions of the skull and hand. The individuals stood about 1.5 to 3 feet (0.5 to 1 meter) tall at the hips and were 3 to 10 feet (1 to 3 meters) long. They weighed about 22 to 66 pounds (10 to 30 kilograms), walked on four legs, and most likely ate plants or a combination of plants and meat.

"The crazy thing about this new dinosaur discovery is that it is so very different from what we all were expecting, especially the fact that it is herbivorous and walked on four legs, said Irmis, who was involved in the researching the discovery over the past three years.

Asilisaurus kongwe is part of a newly recognized group known as silesaurs. "We knew that there were a number of species from the Triassic that were similar to Asilisaurus," said Irmis, "but we were only able to recognize that they formed this group called silesaurs with the new anatomical information from Asilisaurus." Members of the silesaur group were distributed across the globe during the Triassic, when all of the continents were together in a supercontinent called Pangaea.

Silesaurs are the closest relatives of dinosaurs, analogous to the close relationship of humans and chimps. Even though the oldest dinosaurs discovered so far are only 230 million years old, the presence of their closest relatives 10 million to 15 million years earlier implies that silesaurs and the dinosaur lineage had already diverged from a common ancestor by 245 million years ago. Silesaurs continued to live side by side with early dinosaurs throughout much of the Triassic Period (between about 250 million and 200 million years ago). The researchers conclude that other relatives of dinosaurs, such as pterosaurs (flying reptiles) and small forms called lagerpetids, might have also originated much earlier than previously thought.

Silesaurs have triangular teeth and a lower jaw with a beak-like tip, suggesting that they were specialized for an omnivorous and/or herbivorous diet. These same traits evolved independently in at least two dinosaur lineages (ornithischians and sauropodomorphs). In all three cases, the features evolved in animals that were originally meat-eaters. Although difficult to prove, it's possible that this shift conferred an evolutionary advantage. The researchers conclude that the ability to shift diets may have lead to the evolutionary success of these groups.

"The research suggests that at least three times in the evolution of dinosaurs and their closest relatives, meat-eating animals evolved into animals with diets that included plants," said Irmis. "These shifts all occurred in less than 10 million years, a relatively short time by geological standards, so we think that the lineage leading to silesaurs and dinosaurs might have had a greater flexibility in diet, and that this could be a reason for their success."

This new species (Asilisaurus) is found along with a number of primitive crocodilian relatives in the same fossil beds in southern Tanzania. The presence of these animals together at the same time and place suggests that the diversification of the relatives of crocodilians and dinosaurs was rapid, and happened earlier than previously suggested. It sheds light on a group of animals that later came to dominate terrestrial ecosystems throughout the Mesozoic Era (250 million to 65 million years ago).

"This new research suggests that there are more groups of animals yet to be discovered in this early period of dinosaur relatives," said Irmis. "It's very exciting because the more we learn about the Triassic Period, the more we learn about the origin of the dinosaurs and other groups."

University of Utah

30 years later, what killed the dinosaurs is revisited

2010-03-05T09:17:00.002+01:00

Scripps Institution of Oceanography, UC San Diego, paleoceanographer Richard Norris is one of 41 scientists presenting evidence that an asteroid impact really did kill off dinosaurs and myriad other organisms 30 years after the theory was first proposed. The researchers are authors of a review paper being released Friday in the journal Science that represents a new salvo in an ongoing controversy over the cause of the mass extinction. Norris' contribution to the paper was evidence in seafloor sediment records that indicate how deep-sea life was profoundly reshaped by the impact.

"The story is a lot stronger now than 30 years ago, when it was admittedly a little more speculative," said Norris. "Since 1980, we have accumulated an overwhelming amount of evidence that there was an impact. We also think the evidence is overwhelming that there was a mass extinction as a direct result of this event."

In that year, father and son researchers Luis and Walter Alvarez first proposed the notion that an asteroid impact killed off the dinosaurs. They had discovered that high levels of iridium, an element rare on Earth but common on extraterrestrial objects like meteors, were uniformly present in sedimentary samples that could be dated back to the extinction event, which marked the transition between two geologic periods.

At the time, they did not know where on Earth that impact might have taken place. It would be another 11 years before researchers Alan Hildebrand and Glen Penfield suggested that a crater left behind by an asteroid impact was buried on the Yucatan peninsula. With the crater nearly 200 kilometers (125 miles) in diameter, the impact was one large enough to have caused the mass extinction in agreement with the Alvarez hypothesis.

The force of the impact itself — there is evidence of giant earthquakes and tsunami waves more than 1,000 feet tall being generated in the immediate aftermath — and the following profound atmospheric changes combined to make the planet uninhabitable for between 40 and 70 percent of all life forms on Earth.

But rival explanations, though outside the mainstream, have continued to proliferate in high-profile fashion. One theory that has gained widespread attention attributes the mass extinction to a volcanic event in India that took place at roughly the same time as the impact. Another faction of researchers acknowledges that the asteroid did strike but that its effects were not enough to cause the mass extinction.

Norris notes that an inspection of ancient layers of seafloor sediment around the world show a clear record of the event contained in a red or green band composed of materials ejected from the blast. These include pieces of rock like those on the Yucatan, glassy droplets that represent melted rock, microscopic diamonds made under the very high pressures produced by the impact and meteoric debris.

"There are also monster submarine landslides along the entire East Coast of the U.S. from the massive earthquake triggered by the impact," he said.

Norris points to several pieces of evidence from the deep sea that support a tight link between the impact and the mass extinction. In most places in the deep ocean, the impact debris layer is associated with an abrupt decrease in the size of fossils — the appearance of a dwarfed "disaster" fauna. Abrupt environmental changes throughout history such as the impact tend to favor smaller organisms that have more rapid lifecycles and fewer resource needs than larger organisms. Biological productivity plummets in many parts of the oceans immediately after the impact. The drop in productivity is partly reflected by a change in the color of deep-sea sediments — from creamy white to brown or grey — as light-colored fossil shells abruptly decreased in number.

Individually, the decrease in fossil size, the appearance of a "disaster fauna" and the plummet in ocean productivity are unusual, and together with an impact debris layer, are unique in the deep-sea sediment record.

"This is not a 'smoking gun,'" said Norris, "it's a 'smoking cannon.'"

University of California - San Diego

Dinosaurs might be older than previously thought

2010-03-04T09:21:00.001+01:00

Paleontologists announced the discovery of a dinosaur-like animal—one that shared many characteristics with dinosaurs but fell just outside of the dinosaur family tree—living 10 million years earlier than the oldest known dinosaurs. The researchers conclude that dinosaurs and other close relatives such as pterosaurs (flying reptiles) might have also lived much earlier than previously thought. The description of the new species Asilisaurus kongwe (a-SEE-lee- SOAR-us KONG-way) appears in the March 4 issue of the journal Nature in a paper lead-authored by Sterling Nesbitt, a postdoctoral researcher at The University of Texas at Austin's Jackson School of Geosciences. Nesbitt conducted the research with his colleagues while a graduate student at Columbia University's Lamont-Doherty Earth Observatory and the American Museum of Natural History.

The research also suggests that at least three times in the evolution of dinosaurs and their closest relatives, meat-eating animals evolved into animals with diets that included plants. These shifts all occurred in less than 10 million years, a relatively short time by geological standards.

Asilisaurus is part of a sister group to dinosaurs known as silesaurs. Silesaurs are considered dinosaur-like because they share many dinosaur characteristics but still lack key characteristics all dinosaurs share. The relationship between silesaurs and dinosaurs is analogous to the close relationship of humans and chimps. Even though the oldest dinosaurs discovered so far are only 230 million years old, the presence of their closest relatives 10 million years earlier implies that silesaurs and the dinosaur lineage had already diverged from common ancestors by 240 million years ago. Silesaurs continued to live side by side with early dinosaurs throughout much of the Triassic Period (between about 250 and 200 million years ago).

This is the first dinosaur-like animal recovered by archaeologists from the Triassic Period in Africa.

Fossil bones of at least 14 individuals were recovered from a single bone bed in southern Tanzania making it possible to reconstruct a nearly entire skeleton, except portions of the skull and hand. The individuals stood about 0.5 to 1 meter (1.5 to 3 feet) tall at the hips and were 1 to 3 meters (3 to 10 feet) long. They weighed about 10 to 30 kilograms (22 to 66 pounds). Asilisaurus walked on four legs and most likely ate plants or a combination of plants and meat. They lived about 240 million years ago.

Silesaurs have triangular teeth and a lower jaw with a beak like tip which suggest that they were specialized for an omnivorous and/or herbivorous diet. These same traits evolved independently in at least two dinosaur lineages. In all three cases, the features evolved in animals that were originally meat-eaters. Although difficult to prove, it's possible that this shift conferred an evolutionary advantage. An ecosystem can support far more plant eaters than meat eaters. So being able to eat plants might have opened up a broader range of habitats. Not counting modern birds, dinosaurs survived for about 180 million years.

This new species is found along with a number of primitive crocodilian relatives in the same fossil bed in southern Tanzania. The presence of these animals together at the same time and place suggests that the diversification of the relatives of crocodilians and birds was rapid and happened earlier than previously suggested. It sheds light on a group of animals that later came to dominate the terrestrial ecosystem throughout the Mesozoic (250 to 65 million years ago).

"Everyone loves dinosaurs," said Nesbitt. "But this new evidence suggests that they were really only one of several large and distinct groups of animals that exploded in diversity in the Triassic, including silesaurs, pterosaurs, and several groups of crocodilian relatives."

Silesaurus, the first known member of the silesaur group was discovered in 2003. In just 7 short years, specimens of 8 other members have been unearthed from Triassic rocks across the globe.

"This goes to show that there are whole groups of animals out there that we've never even found evidence of that were very abundant during the Triassic," said Nesbitt. "It's exciting because it means there is still so much chance for discovery."

The name Asilisaurus kongwe is derived from asili (Swahili for ancestor or foundation), sauros (Greek for lizard), and kongwe (Swahili for ancient).

University of Texas at Austin

Recently analyzed fossil was not human ancestor as claimed, anthropologists say

2010-03-03T10:03:00.001+01:00

A fossil that was celebrated last year as a possible "missing link" between humans and early primates is actually a forebearer of modern-day lemurs and lorises, according to two papers by scientists at The University of Texas at Austin, Duke University and the University of Chicago. In an article now available online in the Journal of Human Evolution, four scientists present evidence that the 47-million-year-old Darwinius masillae is not a haplorhine primate like humans, apes and monkeys, as the 2009 research claimed.

They also note that the article on Darwinius published last year in the journal PLoS ONE ignores two decades of published research showing that similar fossils are actually strepsirrhines, the primate group that includes lemurs and lorises.

"Many lines of evidence indicate that Darwinius has nothing at all to do with human evolution," says Chris Kirk, associate professor of anthropology at The University of Texas at Austin. "Every year, scientists describe new fossils that contribute to our understanding of primate evolution. What's amazing about Darwinius is, despite the fact that it's nearly complete, it tells us very little that we didn't already know from fossils of closely related species."

His co-authors are anthropologists Blythe Williams and Richard Kay of Duke and evolutionary biologist Callum Ross of the University of Chicago. Williams, Kay and Kirk also collaborated on a related article about to be published in the Proceedings of the National Academy of Sciences that reviews the early fossil record and anatomical features of anthropoids – the primate group that includes monkeys, apes, and humans.

Last spring's much-publicized article on Darwinius was released in conjunction with a book, a History Channel documentary, and an exhibit in the American Museum of Natural History. At a news conference attended by New York Mayor Michael Bloomberg, the authors unveiled the nearly complete fossil of a nine-month-old female primate that had been found at the site of Messel in Germany.

But other anthropologists were immediately skeptical of the conclusions and began writing the responses that are being published this month.

"Just because it's a complete and well-preserved fossil doesn't mean it's going to overthrow all our ideas," says Williams, the lead author. "There's this enormous body of literature that has built up over the years. The Darwinius research completely ignored that body of literature."

That literature centers on the evolution of primates, which include haplorhines (apes, monkeys, humans, tarsiers) and strepsirrhines (lemurs, lorises). The two groups split from each other nearly 70 million years ago.

The fossil group to which Darwinius belongs – the adapiforms – have been known since the early 1800s and includes dozens of primate species represented by thousands of fossils recovered in North America, Europe, Asia and Africa. Some adapiforms, like North American Notharctus, are known from nearly complete skeletons like that of Darwinius. Most analyses of primate evolution over the past two decades have concluded that adapiforms are strepsirrhines, and not direct ancestors of modern humans.

The most recent such analysis, published last year in the journal Nature, concluded that Darwinius is an early strepsirrhine and a close relative of the 39-million-year- old primate Mahgarita stevensi from West Texas.

Nevertheless, the scientists who last year formally described Darwinius concluded that it was an early haplorhine, and even suggested that Darwinius and other adapiform fossils "could represent a stem group from which later anthropoid primates evolved."

For example, they note that Darwinius has a short snout and a deep jaw – two features that are found in monkeys, apes, and humans.

However, Kirk, Williams and their colleagues point out that short snouts and deep jaws are known to have evolved multiple times among primates, including several times within the lemur/loris lineage. They further argue that Darwinius lacks most of the key anatomical features that could demonstrate a close evolutionary relationship with living haplorhines (apes, monkeys, humans, and tarsiers).

For instance, haplorhines have a middle ear with two chambers and a plate of bone that shields the eyes from the chewing muscles.

"There is no evidence that Darwinius shared these features with living haplorhines," says Kirk. "And if you can't even make that case, you can forget about Darwinius being a close relative of humans or other anthropoids."

University of Texas at Austin

'Anaconda' meets 'Jurassic Park': Study shows ancient snakes ate dinosaur babies

2010-03-02T09:57:00.000+01:00

Sixty-seven million years ago, when dinosaur hatchlings first scrambled out of their eggs, their first—and last—glimpse of the world might have been the open jaws of a 3.5-metre-long snake named Sanajeh indicus, based on the discovery in India of a nearly complete fossilized skeleton of a primitive snake coiled inside a dinosaur nest. The snake lacked the wide-jawed gape seen in modern snakes such as pythons and boas, which would have prohibited it from eating rigid dinosaur eggs. But baby dinosaurs would have been just the right prey size for a large snake, says Jason Head, a paleontologist and assistant professor in the Department of Biology at the University of Toronto Mississauga.

"Living primitive snakes are small animals whose diet is limited by their jaw size, but the evolution of a large body size in Sanajeh would have allowed it to eat a wide range of prey, including dinosaur hatchlings," says Head. "This is the first direct evidence of feeding behavior in a fossil primitive snake, and shows us that the ecology and early evolutionary history of snakes were much more complex than we would think just by looking at modern snakes today."

The fossils were first found in 1987 by dinosaur egg expert Dhananjay Mohabey from the Geological Survey of India, in rocks of the Lameta Formation in Gujarat, a state in western India known for its rich fossil record of dinosaurs and their eggs. Originally identified as a hatchling dinosaur, the fossils were recognized to include a snake by dinosaur paleontologist Jeff Wilson from the University of Michigan and Mohabey in 2001.

"I saw the characteristic vertebrae of a snake beside the dinosaur eggshell and larger bones, and I knew it was an extraordinary specimen ... even if I couldn't put the whole story together at that point. I just knew we needed to examine it further," said Wilson. They invited snake specialist Head and geologist Shanan Peters from the University of Wisconsin-Madison, to collaborate on the study of the fossils, including field and lab work in India, the U.S.A., and Canada.

Sanajeh indicus, which means "ancient gape from India", is represented by a nearly complete skull and lower jaws along with vertebrae and ribs coiled around a crushed titanosaur egg, next to the remains of a 0.5-metre-long titanosaur hatchling. These dinosaurs, part of a larger group called sauropods, were long-necked, four-legged plant-eaters that grew to weigh up to 100 tonnes, and Wilson says they likely grew quickly in their first year, beyond the reach of predators like Sanajeh.

The findings—along with two other similar snake-egg pairings, suggest that snakes fed on titanosaur hatchlings when they emerged from their eggs. "The eggs were laid in loose sands and covered by a thin layer of sediment. We think that the hatchling had just exited its egg, and its movement attracted the snake," explains Mohabey. "It would have been a smorgasbord," says Head. "Hundreds or thousands of defenseless baby sauropods could have supported an ecosystem of predators during the hatching season."

The remains capture a moment in Cretaceous time. "Burial was rapid and deep," says Peters. "Probably a pulse of slushy sand and mud released during a storm caught them in the act."

University of Toronto

The bigger the animal, the stiffer the 'shoes'

2010-02-26T09:57:00.001+01:00

If a Tiger's feet were built the same way as a mongoose's feet, they'd have to be about the size of a hippo's feet to support the big cat's weight. But they're not. For decades, researchers have been looking at how different-sized legs and feet are put together across the four-legged animal kingdom, but until now they overlooked the "shoes," those soft pads on the bottom of the foot that bear the brunt of the animal's walking and running.

New research from scientists in Taiwan and at Duke University has found that the mechanical properties of the pads vary in predictable fashion as animals get larger. In short, bigger critters need stiffer shoes.

Kai-Jung Chi, an assistant professor of physics at National Chung Hsing University in Taiwan ran a series of carefully calibrated "compressive tests" on the footpads of carnivores that have that extra toe halfway up the foreleg, including dogs, wolves, domestic cats, leopards and hyenas. She was measuring the relative stiffness of the pads across species – how much they deformed under a given amount of compression.

"People hadn't looked at pads," said co-author V. Louise Roth, an associate professor of biology and evolutionary anthropology who was Chi's thesis adviser at Duke. "They've been looking at the bones and muscles, but not that soft tissue."

Whether running, walking or standing still, the bulk of the animal's weight is borne on that pillowy clover-shaped pad behind the four toes, the metapodial-phalangeal pad, or m-p pad for short. It's made from pockets of fatty tissue hemmed in by baffles of collagen. Chi carefully dissected these pads whole from the feet of deceased animals (none of which were euthanized for this study), so that they could be put in the strain meter by themselves without any surrounding structures.

Laid out on a graph, Chi's analysis of 47 carnivore species shows that the area of their m-p pads doesn't increase at the same rate as the body sizes. But the stiffness of pads does increase with size, and that's what keeps the larger animal's feet from being unwieldy.

The mass of the animal increases cubically with its greater size, but the feet don't scale up the same way. "A mouse and an elephant are made with the same ingredients," Roth said. "So how do you do that?"

Earlier research had found that the stresses on the long bones of the limbs stay fairly consistent over the range of sizes, in part because of changes in posture that distribute the stresses of walking differently, Roth said. But that clearly wasn't enough by itself.

The researchers also found that larger animals have a pronounced difference in stiffness between the pads on the forelimbs and the pads on the hind limbs. Bigger animals have relatively softer pads on their rear feet, whereas in smaller animals the front and rear are about the same stiffness.

Chi thinks the softer pads on the rear of the bigger animals may help them recover some energy from each step, and provide a bit more boost to their propulsion. (Think of the way a large predator folds up its forelimbs and launches itself with its hind legs.)

"It is as if the foot pads' stiffness is tuned to enhance how the animal moves and how strength is maintained in its bones," Roth said.

The research appears today in the Journal of the Royal Society, Interface. It was supported by the National Science Foundation.

Chi has new work under way that looks at the construction of the human heel in the same ways.

Duke University

Small dogs originated in the Middle East

2010-02-25T08:46:00.000+01:00

A genetic study has found that small domestic dogs probably originated in the Middle East more than 12,000 years ago. Researchers writing in the open access journal BMC Biology traced the evolutionary history of the IGF1 gene, finding that the version of the gene that is a major determinant of small size probably originated as a result of the domestication of the Middle Eastern gray wolf. Melissa Gray and Robert Wayne, from the University of California, Los Angeles, led a team of researchers who surveyed a large sample of gray wolf populations. She said, "The mutation for small body size post-dates the domestication of dogs. However, because all small dogs possess this variant of IGF1, it probably arose early in their history. Our results show that the version of the IGF1 gene found in small dogs is closely related to that found in Middle Eastern wolves and is consistent with an ancient origin in this region of small domestic dogs".

Previous archeological work in the Middle East has unearthed the remains of small domestic dogs dating to 12,000 years ago. Sites in Belgium, Germany and Western Russia contain older remains (13,000-31,000 years ago), but these are of larger dogs. These findings support the hypothesis put forward by Gray and colleagues that small body size evolved in the Middle East.

Reduction in body size is a common feature of domestication and has been seen in other domesticated animals including cattle, pigs and goats. According to Gray, "Small size could have been more desirable in more densely packed agricultural societies, in which dogs may have lived partly indoors or in confined outdoor spaces".

BioMed Central

New dinosaur discovered head first, for a change

2010-02-24T10:32:00.001+01:00

A team of paleontologists has discovered a new dinosaur species they're calling Abydosaurus, which belongs to the group of gigantic, long-necked, long-tailed, four-legged, plant-eating dinosaurs such as Brachiosaurus. In a rare twist, they recovered four heads – two still fully intact – from a quarry in Dinosaur National Monument in eastern Utah. Complete skulls have been recovered for only eight of more than 120 known varieties of sauropod.

"Their heads are built lighter than mammal skulls because they sit way out at the end of very long necks," said Brooks Britt, a paleontologist at Brigham Young University. "Instead of thick bones fused together, sauropod skulls are made of thin bones bound together by soft tissue. Usually it falls apart quickly after death and disintegrates."

Britt is a co-author on the discovery paper scheduled to appear in the journal Naturwissenshaften.

The lead author is Daniel Chure, a paleontologist at Dinosaur National Monument, who has no trouble boiling down the significance of the discovery.

"We've got skulls!" he shouted with sweeping hand gestures during a recent visit to the site.

BYU geology students and faculty resorted to jackhammers and concrete saws to cut through the hardened 105-million-year-old sandstone containing the bones. At one point the National Park Service called in a crew to blast away the overlying rock with explosives.

The skulls are temporarily on display at BYU's Museum of Paleontology, where visitors can also watch BYU students prepare other bones from Abydosaurus.

"The hardest bone I personally have worked on is a vertebra that was half-eroded before discovery and is so fragile that it crumbles if you look at it wrong," said Kimmy Hales, a geology major studying vertebrate paleontology at BYU. "The funnest project I have worked on was a set of five toe bones. Each toe bone was larger than my hand."

Analysis of the bones indicates that the closest relative of Abydosaurus is Brachiosaurus, which lived 45 million years earlier. The four Abydosaurus specimens were all juveniles.

Most of what scientists know about sauropods is from the neck down, but the skulls from Abydosaurus give a few clues about how the largest land animals to roam the earth ate their food.

"They didn't chew their food; they just grabbed it and swallowed it," Britt said. "The skulls are only one two-hundredth of total body volume and don't have an elaborate chewing system."

All sauropods ate plants and continually replaced their teeth throughout their lives. In the Jurassic Period, sauropods exhibited a wide range of tooth shapes. But by the end of the dinosaur age, all sauropods had narrow, pencil-like teeth.

Abydosaurus teeth are somewhere in between, reflecting a trend toward smaller teeth and more rapid tooth replacement.

The fossils were excavated from the Cedar Mountain Formation in Dinosaur National Monument near Vernal, Utah. The site is just a quarter of a mile away from the condemned visitor center that displays thousands of bones that remain in place on an uplifted slab of sandstone.

University of Michigan researchers John Whitlock and Jeffrey Wilson are also co-authors on the study.

What's in the name Abydosaurus mcintoshi?

The generic name refers to Abydos, the Greek name for the city along the Nile River (now El Araba el Madfuna) that was the burial place of the head and neck of Osiris, Egyptian god of life, death and fertility. Abydos alludes to the type specimen, which is a skull and neck found in a quarry overlooking the Green River. Sauros is the Greek word for lizard.

The specific name mcintoshi honors the American paleontologist Jack McIntosh for his contributions to the study of sauropod dinosaurs. In 1975 McIntosh debunked the myth of Brontosaurus, exposing it as a mixed-up skeleton with an Apatosaurus body and a Camarasaurus skull.

Brigham Young University

DNA evidence tells 'global story' of human history

2010-02-23T09:35:00.000+01:00

In recent years, DNA evidence has added important new tools for scientists studying the human past. Now, a collection of reviews published by Cell Press in a special issue of Current Biology published online on February 22nd offers a timely update on how new genetic evidence, together with archaeological and linguistic evidence, has enriched our understanding of human history on earth. "To understand what it is to be human, it is essential to understand the human past," says Colin Renfrew of the University of Cambridge, who first coined the term "archaeogenetics" and is the author of a guest editorial in the special issue. "Nearly all civilizations have their own origin or creation myth. Now we can use archaeogenetics to tell a global story that is robust and applicable to all human communities everywhere."

The journey started around 60 to 70 thousand years ago in Africa, where modern humans evolved more than 150 thousand years ago, and where human diversity is still the highest among all continents in terms of genetic variation and languages. From there, humans settled Europe and South Asia and reached Oceania. The Americas (apart from the remote Oceanian islands) were settled last.

The course and the extent of these first migrations remains evident in the genetic makeup of humans living today, but later migrations and the cultural practices that people carried with them—farming in particular—have also left their legacy. That legacy looks remarkably similar wherever farming spread, in Europe, Africa, and East Asia. Natural selection also left its mark: A review by Jonathan Pritchard of the University of Chicago examines evidence for the genetic basis of human adaptations and the extent to which differences among human populations in characteristics such as lactose tolerance have been selected for over evolutionary time.

Each of the reviews is packed with fascinating insights. For instance, a review by Mark Stoneking and Frederick Delfin at the Max Planck Institute for Evolutionary Anthropology tells of an early migration of modern humans from Africa along a southern route to East Asia. Europe is perhaps the best-studied continent in terms of archaeogenetics, writes Martin Richards of the University of Leeds and his colleagues, and includes what Richards refers to as five major episodes, including the repopulation of Northern Europe after the Late Glacial Maximum. In the case of the Americas, DNA evidence has confirmed the Asian origin of indigenous Americans and more precise estimates of when Native Americans emerged. Dennis O'Rourke and Jennifer Raff of the University of Utah note, however, that many questions about the date of the initial colonization of the Americas remain.

Overall, the reviews show just how clear it has become that all of us trace our evolutionary roots to Africa, Renfrew says. For most of history, humans were not evolving in isolation on separate continents. When it comes to our more recent history, stay tuned: Many surprising discoveries are likely in store over the next 20 years.

Of course, there are many things about our ancient ancestors we will never be able to know with any certainty, Partha Majumder of the Indian Statistical Institute reminds us in his review of human genetic history in South Asia.

"About a thousand years ago, a small group of anatomically modern humans migrated out of Africa," he writes. "We will never know for sure which causes initiated this migration… The process continued for thousands of years; today humans occupy the entire world."

Cell Press

New study finds link between marine algae and whale diversity over time

2010-02-22T10:08:00.001+01:00

A new paper by researchers at George Mason University and the University of Otago in New Zealand shows a strong link between the diversity of organisms at the bottom of the food chain and the diversity of mammals at the top. Mark D. Uhen, a geologist at Mason, says that throughout the last 30 million years, changes in the diversity of whale species living at any given time period correlates with the evolution and diversification of diatoms, tiny, abundant algae that live in the ocean. In the paper "Climate, Critters, and Cetaceans: Cenozoic Drivers of the Evolution of Modern Whales," which was published in the latest issue of Science, Uhen and co-author Felix G. Mark of Otago show that the more kinds of diatoms living in a time period, the more kinds of whales there are.

Looking at thousands of published accounts of whale fossil records, the researchers assembled the records in a database to analyze and pinpoint the various fossils. The fossil records show a direct link between the productivity of the ocean and the variety of whale fossils. Uhen says they also found a correlation between global changes and fossil variety.

"This study shows that if we look at the bottom of the food chain, it might tell you something about the top," says Uhen. "Diatoms are key primary producers in the modern ocean, and thus help to form the base of the marine food chain. The fossil record clearly shows that diatoms and whales rose and fell in diversity together during the last 30 million years."

Uhen says this is the first time that such a correlation has been shown. Though scientists in the past have tried to answer the question of how the modern diversity of whale and dolphins arise, this question has been difficult to answer. The fossil record might not truly reflect evolutionary history, says Uhen. "Is it possible that the diversity of fossils we find through geological time might really just reflect the amount of preserved sedimentary rock paleontologists can search – the more rock there is, the more fossils we find? This comprehensive study has shown that the diversity of these fossils is in fact not driven by the sedimentary rock record."

The researchers hope these findings will encourage other specialists to look at other animals with a similar narrow ecology to see if this link translates.

Uhen is a term assistant professor in Mason's Department of Atmospheric, Oceanic and Earth Sciences and is an expert in marine mammal fossils. In the future, he hopes to conduct research on how the body size of whales changes over time, and how whales became the largest living organisms in the world.

George Mason University

Pitt-led study debunks millennia-old claims of systematic infant sacrifice in ancient Carthage

2010-02-19T10:44:00.000+01:00

A study led by University of Pittsburgh researchers could finally lay to rest the millennia-old conjecture that the ancient empire of Carthage regularly sacrificed its youngest citizens. An examination of the remains of Carthaginian children revealed that most infants perished prenatally or very shortly after birth and were unlikely to have lived long enough to be sacrificed, according to a Feb. 17 report in PLoS ONE. The findings—based on the first published analysis of the skeletal remains found in Carthaginian burial urns—refute claims from as early as the 3rd century BCE of systematic infant sacrifice at Carthage that remain a subject of debate among biblical scholars and archaeologists, said lead researcher Jeffrey H. Schwartz, a professor of anthropology and history and philosophy of science in Pitt's School of Arts and Sciences and president of the World Academy of Art and Science. Schwartz and his colleagues present the more benign interpretation that very young Punic children were cremated and interred in burial urns regardless of how they died.

"Our study emphasizes that historical scientists must consider all evidence when deciphering ancient societal behavior," Schwartz said. "The idea of regular infant sacrifice in Carthage is not based on a study of the cremated remains, but on instances of human sacrifice reported by a few ancient chroniclers, inferred from ambiguous Carthaginian inscriptions, and referenced in the Old Testament. Our results show that some children were sacrificed, but they contradict the conclusion that Carthaginians were a brutal bunch who regularly sacrificed their own children."

Schwartz worked with Frank Houghton of the Veterans Research Foundation of Pittsburgh, Roberto Macchiarelli of the National Museum of Natural History in Paris, and Luca Bondioli of the National Museum of Prehistory and Ethnography in Rome to inspect the remains of children found in Tophets, burial sites peripheral to conventional Carthaginian cemeteries for older children and adults. Tophets housed urns containing the cremated remains of young children and animals, which led to the theory that they were reserved for victims of sacrifice.

Schwartz and his coauthors tested the all-sacrifice claim by examining the skeletal remains from 348 urns for developmental markers that would determine the children's age at death. Schwartz and Houghton recorded skull, hip, long bone, and tooth measurements that indicated most of the children died in their first year with a sizeable number aged only two to five months, and that at least 20 percent of the sample was prenatal.

Schwartz and Houghton then selected teeth from 50 individuals they concluded had died before or shortly after birth and sent them to Macchiarelli and Bondioli, who examined the samples for a neonatal line. This opaque band forms in human teeth between the interruption of enamel production at birth and its resumption within two weeks of life. Identification of this line is commonly used to determine an infant's age at death. Macchiarelli and Bondioli found a neonatal line in the teeth of 24 individuals, meaning that the remaining 26 individuals died prenatally or within two weeks of birth, the researchers reported.

The contents of the urns also dispel the possibility of mass infant sacrifice, Schwartz and Houghton noted. No urn contained enough skeletal material to suggest the presence of more than two complete individuals. Although many urns contained some superfluous fragments belonging to additional children, the researchers concluded that these bones remained from previous cremations and may have inadvertently been mixed with the ashes of subsequent cremations.

The team's report also disputes the contention that Carthaginians specifically sacrificed first-born males. Schwartz and Houghton determined sex by measuring the sciatic notch—a crevice at the rear of the pelvis that's wider in females—of 70 hipbones. They discovered that 38 pelvises came from females and 26 from males. Two others were likely female, one likely male, and three undetermined.

Schwartz and his colleagues conclude that the high incidence of prenate and infant mortality are consistent with modern data on stillbirths, miscarriages, and infant death. They write that if conditions in other ancient cities held in Carthage, young and unborn children could have easily succumbed to the diseases and sanitary shortcomings found in such cities as Rome and Pompeii.

University of Pittsburgh

The putative skull of St. Bridget can be questioned

2010-02-18T09:52:00.001+01:00

The putative skull of Saint Bridget (Birgitta) of Sweden that has been kept in a shrine in Vadstena Abbey is probably not authentic. A new study conducted at Uppsala University reveals that the two skulls, believed to be from Saint Bridget and her daughter Catherine (Katarina), is not from maternally related individuals. Furthermore, dating show that the skulls are not from the time period when Bridget and Catherine lived. The findings are published in the journal PLoS ONE. Vadstena parish assigned Associate Professor Marie Allen's research group at Uppsala University's Department of Genetics and Pathology the task of examining DNA of both skulls, in order to confirm kinship and authenticity. A sensitive method based on analysis of the maternally inherited mitochondrial DNA was used to analyse the skulls. This method makes it possible to examine very small amounts of DNA, and it is often a successful analysis on aged and degraded material.

Saint Bridget of Sweden lived between 1303 and 1373, and was canonized in 1391. In 1999, the Pope declared Bridget one of Europe's Patron Saints. According to the legend, the skulls of both Bridget and her daughter Catherine (1331-1381) have been kept as sacred relics at Vadstena Abbey, located in central Sweden. Bridget was renowned for her revelations, prophecies and pilgrimages. After her death, her remains were taken from Rome to Vadstena, where they were placed in a shrine in 1381. Through the years, small pieces of the relics were selected and given to churches, monasteries, kings and popes. Currently, the shrine in Vadstena contains two skulls, as well as 23 other bones. Among these, a femur bone is thought to be from Saint Bridget. A third skull that was stolen from Vadsrena in 1645, is now in an abbey in Holland. An anthropological and archaeological study from the 1950s concluded that the two skulls that remains in Vadstena probably are from two women, aged between 60-70 years and 50-55 years, respectively. This corresponds well with the theory that the skulls in the Vadstena relic shrine could be from Bridget and her daughter Catherine.

The scientists analysed small pieces of the skulls and concluded that both skulls are female by a nuclear DNA-analysis. Moreover, a maternal relationship can be excluded by analysis of mitochondrial DNA. There were indications of a difference in the preservation of the DNA, which could be due to an age difference between the skulls. Therefore, Professor Göran Possnert at Uppsala University's Tandem Laboratory performed further testing, using advanced radiocarbon dating (C-14) technology. The results confirmed those obtained by the DNA analysis.

"One skull cannot be attributed to Bridget or Catherine as it dates back to the period 1470-1670. The other skull, thought to be from Saint Bridget, is dated to 1215-1270 and is thus not likely to be from the 14th Century when Bridget lived. It cannot, however, be completely excluded that the older skull is from Bridget if she had a diet dominated by fish, which can shift the dating results. But this is unlikely," says Göran Possnert.

"The results from both methods support each other. Our DNA analyses show that we can exclude a mother and daughter relationship. This is also confirmed by the dating as a difference of at least 200 years between the skulls is seen," says Marie Allen.

Uppsala University

King Tut's death explained?

2010-02-17T10:11:00.001+01:00

Using several scientific methods, including analyzing DNA from royal mummies, research findings suggest that malaria and bone abnormalities appear to have contributed to the death of Egyptian pharaoh King Tutankhamun, with other results appearing to identify members of the royal family, including King Tut's father and mother, according to a study in the February 17 issue of JAMA. The 18th dynasty (circa 1550-1295 B.C.) of the New Kingdom was one of the most powerful royal houses of ancient Egypt, and included the reign of Tutankhamun, probably the most famous of all pharaohs, although his tenure was brief. He died in the ninth year of his reign, circa 1324 B.C., at age 19 years. "Little was known of Tutankhamun and his ancestry prior to Howard Carter's discovery of his intact tomb (KV62) in the Valley of the Kings in 1922, but his mummy and the priceless treasures buried with him, along with other important archeological discoveries of the 20th century, have provided significant information about the boy pharaoh's life and family," the authors write.

Because Tutankhamun died so young, and left no heirs, there have been numerous speculations regarding diseases that may have occurred in his family, as well as debate regarding the cause of Tutankhamun's death. Also, artifacts have shown the royalty of that era as having a somewhat feminized or androgynous appearance. Diseases that have been suggested to explain this appearance include a form of gynecomastia (excessive development of the breasts in males; usually the result of a hormonal imbalance), Marfan syndrome and others. "However, most of the disease diagnoses are hypotheses derived by observing and interpreting artifacts and not by evaluating the mummified remains of royal individuals apart from these artifacts," they write. There have also been questions regarding the identification of a number of royal mummies from this era and the exact relationships between some members of the royal family.

Zahi Hawass, Ph.D., of the Supreme Council of Antiquities, Cairo, Egypt, and colleagues conducted a study to determine familial relationships among 11 royal mummies of the New Kingdom, and to search for pathological features attributable to inherited disorders, infectious diseases and blood relationship. They also examined for evidence regarding Tutankhamun's death, with some scholars having hypothesized that it was attributable to an injury; septicemia (bloodstream infection) or fat embolism (release of fat into an artery) secondary to a femur fracture; murder by a blow to the back of the head; or poisoning.

From September 2007 to October 2009, royal mummies underwent detailed anthropological, radiological, and genetic studies (DNA was extracted from 2 to 4 different biopsies per mummy). In addition to Tutankhamun, 10 mummies (circa 1410-1324 B.C.) possibly or definitely closely related in some way to Tutankhamun were chosen; of these, the identities were certain for only 3. In addition to these 11 mummies, 5 other royal individuals dating to the early New Kingdom (circa 1550-1479 B.C.) were selected that were distinct from the supposed members of the Tutankhamun lineage. Most of these 5 mummies were used as a morphological (form and structure) and genetic control group. Genetic fingerprinting allowed the construction of a 5-generation pedigree of Tutankhamun's immediate lineage.

The researchers found that several of the anonymous mummies or those with suspected identities were now able to be addressed by name, which included KV35EL, who is Tiye, mother of the pharaoh Akhenaten and grandmother of Tutankhamun, and the KV55 mummy, who is most probably Akhenaten, father of Tutankhamun. This kinship is supported in that several unique anthropological features are shared by the 2 mummies and that the blood group of both individuals is identical. The researchers identified the KV35YL mummy as likely Tutankhamun's mother.

No signs of gynecomastia or Marfan syndrome were found. "Therefore, the particular artistic presentation of persons in the Amarna period is confirmed as a royally decreed style most probably related to the religious reforms of Akhenaten. It is unlikely that either Tutankhamun or Akhenaten actually displayed a significantly bizarre or feminine physique. It is important to note that ancient Egyptian kings typically had themselves and their families represented in an idealized fashion," they write.

The researchers did find an accumulation of malformations in Tutankhamun's family. "Several pathologies including Kohler disease II [bone disorder] were diagnosed in Tutankhamun; none alone would have caused death. Genetic testing for STEVOR, AMA1, or MSP1 genes specific for Plasmodium falciparum [the malaria parasite] revealed indications of malaria tropica in 4 mummies, including Tutankhamun's. These results suggest avascular bone necrosis [condition in which the poor blood supply to the bone leads to weakening or destruction of an area of bone] in conjunction with the malarial infection as the most likely cause of death in Tutankhamun. Walking impairment and malarial disease sustained by Tutankhamun is supported by the discovery of canes and an afterlife pharmacy in his tomb," the authors write. They add that a sudden leg fracture, possibly from a fall, might have resulted in a life-threatening condition when a malaria infection occurred.

"In conclusion, this study suggests a new approach to research into the molecular genealogy and pathogen paleogenomics of the Pharaonic era. With additional data, a scientific discipline called molecular Egyptology might be established and consolidated, thereby merging natural sciences, life sciences, cultural sciences, humanities, medicine, and other fields."

JAMA and Archives Journals

Meteorite That Fell in 1969 Still Revealing Secrets of the Early Solar System

2010-02-16T10:06:00.002+01:00

A new analysis of the Murchison meteorite, which fell to Earth more than 40 years ago, reveals tens of thousands of organic compounds.

Fragments of a chemically primitive meteorite that landed near Murchison, Australia, in 1969 have long been known to harbor a variety of interesting compounds, including dozens of amino acids. But as analytic techniques become more sophisticated, the Murchison meteorite continues to reveal even more diversity and complexity in the early solar system, and new work by a team of European researchers is no exception.

In the study, set to be published in Proceedings of the National Academy of Sciences, analytical chemist Philippe Schmitt-Kopplin of the Helmholtz German Research Center for Environmental Health in Munich and his colleagues used high-resolution mass spectrometry to look at the organic (carbon-based) content of three Murchison samples. The group found more than 14,000 unique molecular compositions, or collections of atoms, in the samples; there may be 50,000 or more such compositions, if the limited scope of the mass spectrometry analysis is taken into account. And because each collection of atoms can be arranged in numerous ways, the authors estimate that there may be millions of distinct organic compounds in the meteorite.

Many researchers have analyzed the chondritic meteorite for amino acids and other possible precursors to life, because some theories hold that life on Earth began with the delivery of prebiotic organic compounds from space via asteroids or comets. Schmitt-Kopplin says that he and his colleagues took a less targeted approach to try to unlock the meteorite's full chemical complexity and, by extension, the chemical complexity of the early solar system. "What we've seen out of this is that we had such a multitude of signals as we never saw in any other sample before," he says. "Even in petroleum, you have really complex materials, but not necessarily as complex as this."

Daniel Glavin, an astrobiologist at the NASA Goddard Space Flight Center in Greenbelt, Md., who did not contribute to the latest study, has worked on Murchison and other meteorites to look for possible precursors to life that may have arrived on Earth from space. "I think that the issue of diversity and complexity in chemistry is something that has been known for a while with meteorites," Glavin says. "I don't think we knew it was this complex, as what they're showing."

Murchison is a popular meteorite for study partly because roughly 100 kilograms of its stony fragments were quickly collected in 1969 and so did not suffer from much terrestrial contamination. It carries the signature of the solar system from around the time of the sun's formation, roughly 4.6 billion years ago. "It really is some of the first condensates of the early solar system," Glavin says. "This stuff basically freezes a record of some of the earliest chemistry taking place in the solar system that we have access to."

Glavin and his colleagues have had similar success in applying modern analytic approaches to the Murchison meteorite in a targeted search for compounds more relevant to life, finding evidence for hundreds of amino acids. "It really shows the benefits of having these samples and keeping them around until new, more advanced techniques come about to analyze them," Glavin says.

He notes that it will take time to match specific compounds to the potentially millions of chemical species in the Murchison meteorites. "It's exciting, but it also scares me at the same time," Glavin says. "We have a lot of work to do to even pretend to understand what this stuff is."

scientificamerican.com

On Crete, New Evidence of Very Ancient Mariners

2010-02-16T10:03:00.002+01:00

Early humans, possibly even prehuman ancestors, appear to have been going to sea much longer than anyone had ever suspected.

That is the startling implication of discoveries made the last two summers on the Greek island of Crete. Stone tools found there, archaeologists say, are at least 130,000 years old, which is considered strong evidence for the earliest known seafaring in the Mediterranean and cause for rethinking the maritime capabilities of prehuman cultures.

Crete has been an island for more than five million years, meaning that the toolmakers must have arrived by boat. So this seems to push the history of Mediterranean voyaging back more than 100,000 years, specialists in Stone Age archaeology say. Previous artifact discoveries had shown people reaching Cyprus, a few other Greek islands and possibly Sardinia no earlier than 10,000 to 12,000 years ago.

The oldest established early marine travel anywhere was the sea-crossing migration of anatomically modern Homo sapiens to Australia, beginning about 60,000 years ago. There is also a suggestive trickle of evidence, notably the skeletons and artifacts on the Indonesian island of Flores, of more ancient hominids making their way by water to new habitats.

Even more intriguing, the archaeologists who found the tools on Crete noted that the style of the hand axes suggested that they could be up to 700,000 years old. That may be a stretch, they conceded, but the tools resemble artifacts from the stone technology known as Acheulean, which originated with prehuman populations in Africa.

More than 2,000 stone artifacts, including the hand axes, were collected on the southwestern shore of Crete, near the town of Plakias, by a team led by Thomas F. Strasser and Eleni Panagopoulou. She is with the Greek Ministry of Culture and he is an associate professor of art history at Providence College in Rhode Island. They were assisted by Greek and American geologists and archaeologists, including Curtis Runnels of Boston University.

Dr. Strasser described the discovery last month at a meeting of the Archaeological Institute of America. A formal report has been accepted for publication in Hesparia, the journal of the American School of Classical Studies in Athens, a supporter of the fieldwork.

The Plakias survey team went in looking for material remains of more recent artisans, nothing older than 11,000 years. Such artifacts would have been blades, spear points and arrowheads typical of Mesolithic and Neolithic periods.

“We found those, then we found the hand axes,” Dr. Strasser said last week in an interview, and that sent the team into deeper time.

“We were flummoxed,” Dr. Runnels said in an interview. “These things were just not supposed to be there.”

Word of the find is circulating among the ranks of Stone Age scholars. The few who have seen the data and some pictures — most of the tools reside in Athens — said they were excited and cautiously impressed. The research, if confirmed by further study, scrambles timetables of technological development and textbook accounts of human and prehuman mobility.

Ofer Bar-Yosef, an authority on Stone Age archaeology at Harvard, said the significance of the find would depend on the dating of the site. “Once the investigators provide the dates,” he said in an e-mail message, “we will have a better understanding of the importance of the discovery.”

Dr. Bar-Yosef said he had seen only a few photographs of the Cretan tools. The forms can only indicate a possible age, he said, but “handling the artifacts may provide a different impression.” And dating, he said, would tell the tale.

Dr. Runnels, who has 30 years’ experience in Stone Age research, said that an analysis by him and three geologists “left not much doubt of the age of the site, and the tools must be even older.”

The cliffs and caves above the shore, the researchers said, have been uplifted by tectonic forces where the African plate goes under and pushes up the European plate. The exposed uplifted layers represent the sequence of geologic periods that have been well studied and dated, in some cases correlated to established dates of glacial and interglacial periods of the most recent ice age. In addition, the team analyzed the layer bearing the tools and determined that the soil had been on the surface 130,000 to 190,000 years ago.

Dr. Runnels said he considered this a minimum age for the tools themselves. They include not only quartz hand axes, but also cleavers and scrapers, all of which are in the Acheulean style. The tools could have been made millenniums before they became, as it were, frozen in time in the Cretan cliffs, the archaeologists said.

Dr. Runnels suggested that the tools could be at least twice as old as the geologic layers. Dr. Strasser said they could be as much as 700,000 years old. Further explorations are planned this summer.

The 130,000-year date would put the discovery in a time when Homo sapiens had already evolved in Africa, sometime after 200,000 years ago. Their presence in Europe did not become apparent until about 50,000 years ago.

Archaeologists can only speculate about who the toolmakers were. One hundred and thirty thousand years ago, modern humans shared the world with other hominids, like Neanderthals and Homo heidelbergensis. The Acheulean culture is thought to have started with Homo erectus.

The standard hypothesis had been that Acheulean toolmakers reached Europe and Asia via the Middle East, passing mainly through what is now Turkey into the Balkans. The new finds suggest that their dispersals were not confined to land routes. They may lend credibility to proposals of migrations from Africa across the Strait of Gibraltar to Spain. Crete’s southern shore where the tools were found is 200 miles from North Africa.

“We can’t say the toolmakers came 200 miles from Libya,” Dr. Strasser said. “If you’re on a raft, that’s a long voyage, but they might have come from the European mainland by way of shorter crossings through Greek islands.”

But archaeologists and experts on early nautical history said the discovery appeared to show that these surprisingly ancient mariners had craft sturdier and more reliable than rafts. They also must have had the cognitive ability to conceive and carry out repeated water crossing over great distances in order to establish sustainable populations producing an abundance of stone artifacts.

NY Times

Chemical analyses uncover secrets of an ancient amphora

2010-02-15T11:26:00.002+01:00

A team of chemists from the University of Valencia (UV) has confirmed that the substance used to hermetically seal an amphora found among remains at Lixus, in Morocco, was pine resin. The scientists also studied the metallic fragments inside the 2,000-year-old vessel, which could be fragments of material used for iron-working. In 2005, a group of archaeologists from the UV discovered a sealed amphora among the remains at Lixus, an ancient settlement founded by the Phoenicians near Larache, in Morocco. Since then, researchers from the Department of Analytical Chemistry at this university have been carrying out various studies into it components.

The latest study, published recently in the journal Analytical Letters, focuses on the resinous material that sealed the vessel. There are remains of a circular rope-effect decoration around the mouth of the amphora, and on which some fingerprints of the craftsman who moulded it can still be seen. It would probably have been sealed with a lid of cork or wood, of which nothing remains, possibly including a ceramic operculum, such as those found nearby.

"We have studied the substance that was used to seal the container using three different techniques, and we compared it with pine resin from today", José Vicente Gimeno, one of the authors of the study and a senior professor at the UV, tells SINC.

The results confirm that the small sample analysed, which is 2,000 years old, contains therpenic organic compounds (primaric, isoprimaric and dehydroabietic acids), allowing this to be classified as resin from a tree from the Pinus genus.

The researchers have identified some substances that indicate the age of resins, such as such as 7-oxo-DHA acid, although this kind of compound was not abundant in the sample due to the amphora's good state of preservation. In addition, Gimeno says that the archaeological resin of the amphora found was hard and blackish with yellow spots, unlike present-day resin, which is more malleable and orangey in colour, similar to the fresh sap of the tree.

Italic amphora in the Straits of Gibraltar

"The jar was found in an area that must have been the amphora store of a house from the period between 50 BCE and 10 CE", Carmen Aranegui, coordinator of the excavations at Lixus and also a senior professor at the UV, tells SINC.

The archaeologist, who has been working at the site for the past 15 years with the Institut National des Sciences de l'Archéologie et du Patrimoine of Rabat, says the amphora is Italic, probably from the region of Campania. It is currently being housed in the archaeological warehouse at Larache. These jars were used as containers for wine or salted products, but after serving this purpose they could be re-used as watertight storage containers. The amphora found contains metallic fragments, and the scientists have analysed these too.

According to the experts, it is likely that this vessel was undergoing a second use, protecting pieces of iron from corrosion, so that they could later be used in the iron-forging process in a local foundry at the time.

Not far from this amphora, another has been found at Lixus bearing the mark in Latin 'A.MISE', which is the name of the person who made the jar, and has also been found on another similar one found in Cadiz, Spain. "This was a period when there was great contact between these two cities on either side of the Straits of Gibraltar", points out Aranegui.

FECYT - Spanish Foundation for Science and Technology

Queen's helps produce archaeological 'time machine'

2010-02-12T11:09:00.002+01:00

Researchers at Queen's University have helped produce a new archaeological tool which could answer key questions in human evolution. The new calibration curve, which extends back 50,000 years is a major landmark in radiocarbon dating-- the method used by archaeologists and geoscientists to establish the age of carbon-based materials.

It could help research issues including the effect of climate change on human adaption and migrations.

The project was led by Queen's University Belfast through a National Environment Research Centre (NERC) funded research grant to Dr Paula Reimer and Professor Gerry McCormac from the Centre for Climate, the Environment and Chronology (14CHRONO) at Queen's and statisticians at the University of Sheffield.

Ron Reimer and Professor Emeritus Mike Baillie from Queen's School of Geography, Archaeology and Palaeoecology also contributed to the work.

The curve called INTCAL09, has just been published in the journal Radiocarbon. It not only extends radiocarbon calibration but also considerably improves earlier parts of the curve.

Dr Reimer said: "The new radiocarbon calibration curve will be used worldwide by archaeologists and earth scientists to convert radiocarbon ages into a meaningful time scale comparable to historical dates or other estimates of calendar age.

"It is significant because this agreed calibration curve now extends over the entire normal range of radiocarbon dating, up to 50,000 years before today. Comparisons of the new curve to ice-core or other climate archives will provide information about changes in solar activity and ocean circulation."

It has taken nearly 30 years for researchers to produce a calibration curve this far back in time.

Since the early 1980s, an international working group called INTCAL has been working on the project.

The principle of radiocarbon dating is that plants and animals absorb trace amounts of radioactive carbon-14 from carbon dioxide in the atmosphere while they are alive but stop doing so when they die. The carbon-14 decays from archaeological and geological samples so the amount left in the sample gives an indication of how old the sample is.

As the amount of carbon -14 in the atmosphere is not constant, but varies with the strength of the earth's magnetic field, solar activity and ocean radiocarbon ages must be corrected with a calibration curve.

Most experts consider the technical limit of radiocarbon dating to be about 50,000 years, after which there is too little carbon-14 left to measure accurately with present day technology.

Queen's University Belfast

Byzantine-era street found in Jerusalem

2010-02-11T10:18:00.002+01:00

With the help of an ancient mosaic map, Israeli archaeologists said Wednesday they have unearthed a section of an old stone-flagged street in Jerusalem that provides important new evidence about the city's commercial life 1,500 years ago.

The 20-foot (6-meter) section of street passes from the west into the center of Jerusalem's Old City, and stands upon a large cistern that supplied water to the city's 30,000 to 40,000 residents. Pottery, coins and bronze weights used to measure precious metals from Byzantine times also were found.

The discovery conforms to the layout of the city depicted in a famous 6th-century mosaic map discovered more than 100 years ago in a Jordanian church, said excavation director Ofer Sion.

The map has long been used as a guide to understanding the shape of the city from the 4th to 6th centuries, and the direction of the street is new evidence the map is correct, he said.

Jerusalem during this time had become a Roman city named Aelia Capitolina, with Jews barred from entering after their revolt against their Roman overlords in 132 A.D. It became a major center for the emerging Christian religion.

The Byzantine Empire evolved out of the eastern half of the Roman Empire when the western part succumbed to barbarian invasions and ruled over much of the Middle East until the Arab conquests of the 7th century.

A staunchly Christian empire based in Constantinople, now Istanbul, it valued Jerusalem as a key Christian religious center and invested heavily into the city, which became a destination for thousands of pilgrims every year.

"This street was the center during the most (commercially) successful period in the history of (ancient) Jerusalem," Sion said. "It is wonderful that (today's street) actually preserved the route of the noisy street from 1,500 years ago."

Working from the historic map, archaeologists three months ago uncovered the section of the wide, white stone street 14 feet (4.5 meters) below the current street level.

Archaeologists have already excavated another ancient street in Jerusalem from that time known as the Cardo, which ran north to south and hosted many shops along its pillared length. Sion said the newly found street included a sidewalk and row of columns.

The map, uncovered in 1894 on the floor of a Byzantine-era church in Madaba, Jordan, shows the locations of major streets and the Christian sites in the city, including the Church of the Holy Sepulcher, the site where the faithful believe Jesus was crucified, buried and resurrected.

Once restoration work is completed, within the next few weeks, the segment of street will be covered because of heavy pedestrian traffic, Sion said. It has yet to be decided if the site will be available for viewing.

The Israel Antiquities Authority undertook the project in response to a municipal plan to build an electric cable system on the site. In a land where every shovel might unearth something ancient, Israeli law requires the authority to inspect construction zones for ruins before work begins.

msnbc.msn.com

What was that? Unraveling a 400-million-year-old mystery

2010-02-11T10:16:00.001+01:00

Contradictions and puzzles surround the giant fossil Prototaxites. The fossils resemble tree trunks, and yet they are from a time before trees existed. The stable carbon isotope values are similar to those of fungi, but the fossils do not display structures usually found in fungi. Plant-like polymers have been found in the fossils, but nutritional evidence supports heterotrophy, which is not commonly found in plants. These are a few of the confounding factors surrounding the identification of Prototaxites fossils. Since the first fossil of Prototaxites was described in 1859, researchers have hypothesized that these organisms were giant algae, fungi, or lichens. A recent study by Dr. Linda Graham and her colleagues published evidence in the February issue of the American Journal of Botany that they believe resolves this long-standing mystery (http://www.amjbot.org/cgi/content/full/97/2/268).

Prototaxites existed during the Late Silurian to Late Devonian periods-- approximately 420-370 million years ago (ma). Prototaxites fossils have a consistent tubular anatomy, composed of primarily unbranched, non-septate tubes, arranged in concentric or eccentric rings, giving the fossils an appearance similar to that of a cross-section of a tree trunk. The fossil "trunks" vary in size and may be up to 8.8 m long and 1.37 m in diameter, making Prototaxites the largest organism on land during the Late Siluarian and Devonian periods.

Graham and her colleagues hypothesized that Prototaxites fossils may be composed of partially degraded wind-, gravity-, or water-rolled mats of mixotrophic (capable of deriving energy from multiple sources) liverworts that are associated with fungi and cyanobacteria. This situation resembles the mats produced by the modern liverwort genus Marchantia. The authors tested their hypothesis by treating Marchantia polymorpha in a manner to reflect the volcanically-influenced, warm environments typical of the Devonian period and compared the resulting remains to Prototaxites fossils. Graham and her colleagues investigated the mixotrophic ability of M. polymorpha by assessing whether M. polymorpha grown in a glucose-based medium is capable of acquiring carbon from its substrate.

"For our structural comparative work," Graham said, "we were extremely fortunate to have an amazing thin slice of the rocky fossil, made in 1954 by the eminent paleobotanist Chester A. Arnold."

Their structural and physiological studies showed that the fossil Prototaxites and the modern liverwort Marchantia have many similarities in their external structure, internal anatomy, and nutrition. Despite being subjected to conditions that would promote decomposition and desiccation, the rhizoids of M. polymorpha survived degradation, and with the mat rolled, created the appearance of concentric circles. The fungal hyphae associated with living liverworts also survived treatment, suggesting that the branched tubes in fossils may be fungal hyphae. The very narrow tubes in the fossils resemble filamentous cyanobacteria that the researchers found wrapped around the rhizoids of the decaying M. polymorpha.

"We were really excited when we saw how similar the ultrastructure of our liverwort rhizoid walls was to images of Prototaxites tubes published in 1976 by Rudy Schmid," Graham said.

In their investigations into the nutritional requirements of M. polymorpha, Graham and her colleagues found that the growth of M. polymorpha in a glucose-based medium was approximately 13 times that seen when the liverwort was grown in a medium without glucose. Stable carbon isotope analyses indicated that less than 20% of the carbon in the glucose-grown liverwort came from the atmosphere. The stable carbon isotope values obtained from M. polymorpha grown with varying amounts of cyanobacteria present span the range of values reported for Prototaxites fossils. Taken together, these results demonstrate that the liverworts have a capacity for mixotrophic nutrition when glucose is present and that mixotrophy and/or the presence of cyanobacteria could be responsible for the stable carbon isotope values obtained from Prototaxites.

Graham and her colleagues' results demonstrate that liverworts were important components of Devonian ecosystems. Their results support previous hypotheses that microbial associations and mixotrophy are ancient plant traits, rather than ones that have evolved recently.

American Journal of Botany

Why Did Mammals Survive the 'K/T Extinction'?

2010-02-10T08:47:00.001+01:00

Picture a dinosaur. Huge, menacing creatures, they ruled the Earth for nearly 200 million years, striking fear with every ground-shaking stride. Yet these great beasts were no match for a 6-mile wide meteor that struck near modern-day Mexico 65 million years ago, incinerating everything in its path. This catastrophic impact -- called the Cretaceous-Tertiary or K/T extinction event -- spelled doom for the dinosaurs and many other species. Some animals, however, including many small mammals, managed to survive.

How did they do it?

"They were better at escaping the heat," said Russ Graham, senior research associate in geosciences at Penn State. "It was the huge amount of thermal heat released by the meteor strike that was the main cause of the K/T extinction."

He said underground burrows and aquatic environments protected small mammals from the brief but drastic rise in temperature. In contrast, the larger dinosaurs would have been completely exposed, and vast numbers would have been instantly burned to death.

After several days of searing heat, the earth's surface temperature returned to bearable levels, and the mammals emerged from their burrows, but it was a barren wasteland they encountered, one that presented yet another set of daunting conditions to be overcome, Graham said. It was their diet which enabled these mammals to survive in habitats nearly devoid of plant life.

"Even if large herbivorous dinosaurs had managed to survive the initial meteor strike, they would have had nothing to eat," he said, "because most of the earth's above-ground plant material had been destroyed."

Mammals, in contrast, could eat insects and aquatic plants, which were relatively abundant after the meteor strike. As the remaining dinosaurs died off, mammals began to flourish. Although representatives from other classes of animals also survived the K/T extinction -- crocodiles, for instance, had the saving ability to take to water -- mammals were clearly the main beneficiaries and they have since spread to nearly every corner of the planet.

Penn State (2010, February 10). Why did mammals survive the 'K/T extinction'?. ScienceDaily. Retrieved February 10, 2010, from http://www.sciencedaily.com /releases/2010/01/100131221348.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29

Has the mystery of the Portrait of Maud Abrantes been solved?

2010-02-10T08:45:00.002+01:00

A century after Amedeo Modigliani painted the Portrait of Maud Abrantes, the mystery behind the painting might be solved. Ofra Rimon, Director and Curator of the Hecht Museum at the University of Haifa, discovered that hidden in the painting is the portrait of another woman. "Modigliani was probably not happy with that painting and decided to paint over it in favor of a portrait of Maud," she claims. In 1908 Modigliani painted the Portrait of Maud Abrantes on the same canvas as he had painted Nude with a Hat earlier that year. Like many painters with limited means during that period, he turned the canvas over to use the other side. But unlike common practice, he also turned it upside down. Even though this was such an irregular act, and despite the fact that the two paintings are central to most Modigliani exhibitions over recent years, art researchers have not given their attention to this oddity.

Even at the Hecht Museum, where the canvas hangs in a special panel that enables viewing it from both sides, Maud Abrantes and Nude with a Hat have alternatively 'stood on their head' since 1989, without causing much wonderment over why the artist did such an unusual thing.

As Rimon showed this unique work to guests at the Hecht Museum, she suddenly noticed another woman: In the area of Maud's neck and chest a sharp eye can make out the outline of the face of a woman in a hat.

"For years I have passed by the painting almost every day and have stood in front of it providing countless explanations. But I never noticed anything irregular about the portrait, and have only been frustrated by Modigliani's disregard for onlookers who are made to view one of the paintings upside down. Then, just out of the blue, when I was escorting guests in the art wing and drew their attention to this fantastic Modigliani piece, the mystery was solved. In my excitement, I shrieked, 'Here's the answer! The mystery is solved! There is another portrait beneath Maud's and this one is facing the other direction to Maud.' The eyes, facial outline and hat can be discerned. It turns out that Modigliani painted the portrait of this mysterious and hidden woman before painting the portrait of Maud Abrantes. He decided not to keep the first painting and blurred it with brushes of color. But that did not suffice: he also turned the canvas over and began to paint anew on the clean part of the canvas," she explained.

University of Haifa

New theory on the origin of primates

2010-02-09T11:03:00.001+01:00

A new model for primate origins is presented in Zoologica Scripta, published by the Norwegian Academy of Science and Letters and The Royal Swedish Academy of Sciences. The paper argues that the distributions of the major primate groups are correlated with Mesozoic tectonic features and that their respective ranges are congruent with each evolving locally from a widespread ancestor on the supercontinent of Pangea about 185 million years ago. Michael Heads, a Research Associate of the Buffalo Museum of Science, arrived at these conclusions by incorporating, for the first time, spatial patterns of primate diversity and distribution as historical evidence for primate evolution. Models had previously been limited to interpretations of the fossil record and molecular clocks.

"According to prevailing theories, primates are supposed to have originated in a geographically small area (center of origin) from where they dispersed to other regions and continents" said Heads, who also noted that widespread misrepresentation of fossil molecular clocks estimates as maximum or actual dates of origin has led to a popular theory that primates somehow crossed the globe and even rafted across oceans to reach America and Madagascar.

In this new approach to molecular phylogenetics, vicariance, and plate tectonics, Heads shows that the distribution ranges of primates and their nearest relatives, the tree shrews and the flying lemurs, conforms to a pattern that would be expected from their having evolved from a widespread ancestor. This ancestor could have evolved into the extinct Plesiadapiformes in north America and Eurasia, the primates in central-South America, Africa, India and south East Asia, and the tree shrews and flying lemurs in South East Asia.

Divergence between strepsirrhines (lemurs and lorises) and haplorhines (tarsiers and anthropoids) is correlated with intense volcanic activity on the Lebombo Monocline in Africa about 180 million years ago. The lemurs of Madagascar diverged from their African relatives with the opening of the Mozambique Channel (160 million years ago), while New and Old World monkeys diverged with the opening of the Atlantic about 120 million years ago.

"This model avoids the confusion created by the center of origin theories and the assumption of a recent origin for major primate groups due to a misrepresentation of the fossil record and molecular clock divergence estimates" said Michael from his New Zealand office. "These models have resulted in all sorts of contradictory centers of origin and imaginary migrations for primates that are biogeographically unnecessary and incompatible with ecological evidence".

The tectonic model also addresses the otherwise insoluble problem of dispersal theories that enable primates to cross the Atlantic to America, and the Mozambique Channel to Madagascar although they have not been able to cross 25 km from Sulawesi to Moluccan islands and from there travel to New Guinea and Australia.

Heads acknowledged that the phylogenetic relationships of some groups such as tarsiers, are controversial, but the various alternatives do not obscure the patterns of diversity and distribution identified in this study.

Biogeographic evidence for the Jurassic origin for primates, and the pre-Cretaceous origin of major primate groups considerably extends their divergence before the fossil record, but Heads notes that fossils only provide minimal dates for the existence of particular groups, and there are many examples of the fossil record being extended for tens of millions of years through new fossil discoveries.

The article notes that increasing numbers of primatologists and paleontologists recognize that the fossil record cannot be used to impose strict limits on primate origins, and that some molecular clock estimates also predict divergence dates pre-dating the earliest fossils. These considerations indicate that there is no necessary objection to the biogeographic evidence for divergence of primates beginning in the Jurassic with the origin of all major groups being correlated with plate tectonics.

Buffalo Museum of Science

Ancient remains put teeth into Barker hypothesis

2010-02-08T10:44:00.001+01:00

Ancient human teeth are telling secrets that may relate to modern-day health: Some stressful events that occurred early in development are linked to shorter life spans. "Prehistoric remains are providing strong, physical evidence that people who acquired tooth enamel defects while in the womb or early childhood tended to die earlier, even if they survived to adulthood," says Emory University anthropologist George Armelagos.

Armelagos led a systematic review of defects in teeth enamel and early mortality recently published in Evolutionary Anthropology. The paper is the first summary of prehistoric evidence for the Barker hypothesis – the idea that many adult diseases originate during fetal development and early childhood.

"Teeth are like a snapshot into the past," Armelagos says. "Since the chronology of enamel development is well known, it's possible to determine the age at which a physiological disruption occurred. The evidence is there, and it's indisputable."

The Barker hypothesis is named after epidemiologist David Barker, who during the 1980s began studying links between early infant health and later adult health. The theory, also known as the Developmental Origins of Health and Disease Hypothesis (DOHaD), has expanded into wide acceptance.

As one of the founders of the field of bioarcheology, Armelagos studies skeletal remains to understand how diet and disease affected populations. Tooth enamel can give a particularly telling portrait of physiological events, since the enamel is secreted in a regular, ring-like fashion, starting from the second trimester of fetal development. Disruptions in the formation of the enamel, which can be caused by disease, poor diet or psychological stress, show up as grooves on the tooth surface.

Armelagos and other bioarcheologists have noted the connection between dental enamel and early mortality for years. For the Evolutionary Biology paper, Armelagos led a review of the evidence from eight published studies, applying the lens of the Barker hypothesis to remains dating back as far as 1 million years.

One study of a group of Australopithecines from the South African Pleistocence showed a nearly 12-year decrease in mean life expectancy associated with early enamel defects. In another striking example, remains from Dickson Mounds, Illinois, showed that individuals with teeth marked by early life stress lived 15.4 years less than those without the defects.

"During prehistory, the stresses of infectious disease, poor nutrition and psychological trauma were likely extreme. The teeth show the impact," Armelagos says.

Until now, teeth have not been analyzed using the Barker hypothesis, which has mainly been supported by a correlation between birth weight in modern-day, high-income populations and ailments like diabetes and heart disease.

"The prehistoric data suggests that this type of dental evidence could be applied in modern populations, to give new insights into the scope of the Barker hypothesis," Armelagos says. "Bioarcheology is yielding lessons that are still relevant today in the many parts of the world in which infectious diseases and under-nutrition are major killers."

Emory University

Yale scientists complete color palette of a dinosaur for the first time

2010-02-05T09:56:00.001+01:00

Deciphering microscopic clues hidden within fossils, scientists have uncovered the vibrant colors that adorned a feathered dinosaur extinct for 150 million years, a Yale University-led research team reports online Feb. 4 in the journal Science. Unlike recently published work from China that inferred the existence of two types of melanin pigments in various species of feathered dinosaurs, the Science study analyzed color-imparting structures called melanosomes from an entire fossil of a single animal, a feat which enabled researchers to reveal rich color patterns of the entire animal.

In fact, the analysis of melanosomes conducted by Yale team was so precise that the team was able to assign colors to individual feathers of Anchiornis huxleyi, a four-winged troodontid dinosaur that lived during the late Jurassic period in China. This dinosaur sported a generally gray body, a reddish-brown, Mohawk-like crest and facial speckles, and white feathers on its wings and legs, with bold black-spangled tips.

"This was no crow or sparrow, but a creature with a very notable plumage," said Richard O. Prum, chair and the William Robertson Coe Professor of Ornithology, Ecology and Evolutionary Biology at Yale and a co-author of the study. "This would be a very striking animal if it was alive today."

The color patterns of the limbs, which strongly resemble those sported by modern day Spangled Hamburg chickens, probably functioned in communication and may have helped the dinosaur to attract mates, suggested Prum.

The transformation of mankind's view of dinosaurs from dull to flamboyant was made possible by a discovery by Yale graduate student Jakob Vinther in the Department of Geology and Geophysics. Vinther was studying the ink sac of an ancient squid and realized that microscopic granular-like features within the fossil were actually melanosomes – a cellular organelle that contains melanin, a light-absorbing pigment in animals, including birds.

While some scientists thought these granules were remnants of ancient bacteria, Vinther, Prum and Derek E.G. Briggs, the Frederick William Beinecke Professor of Geology and Geophysics and director of the Yale Peabody Museum of Natural History, disagreed. First, they tested Vinther's theory on a 112 million year old feather from Brazil and later inferred the colors of an extinct 47 million-year-old bird.

The latest research team — which also included scientists from the University of Texas at Austin, University of Akron, Peking University and the Beijing Museum of Natural History — decided to use the same procedures to closely examine a fossil of Anchiornis huxleyi, recently described in Liaoning Province, People's Republic of China. The area has been a gold mine for paleontologists and, among other things, provided abundant evidence confirming a once-controversial theory that modern birds are descendants of theropod dinosaurs.

The Yale team and Julia Clarke, an associate professor of paleontology at the University of Texas at Austin's Jackson School of Geosciences, worked closely with Gao Keqin of Peking University and Li Quanguo and Meng Qingjin of the Beijing Museum of Natural History to select, sample and evaluate the anatomy and feathering of Anchiornis huxleyi, important in its own right as a new feathered dinosaur. The team's effort was funded by a special grant from the National Geographic Society and by the National Science Foundation.

The team closely examined 29 feather samples from the dinosaur and did an exhaustive measurement and location of melanosomes within the feathers. The team then did a statistical analysis of how those melanosomes compared to the types of melanosomes known to create particular colors in living birds, using data compiled by Matt Shawkey and colleagues at the University of Akron. The analysis allowed scientists to discern with 90 percent certainty the colors of individual feathers and, therefore, the colorful patterns of an extinct animal.

The research adds significant weight to the idea that dinosaurs first evolved feathers not for flight but for some other purposes.

"This means a color-patterning function — for example, camouflage or display — must have had a key role in the early evolution of feathers in dinosaurs, and was just as important as evolving flight or improved aerodynamic function," Clarke said.

The new discoveries provide a wealth of insights into the compelling history of feather evolution in dinosaurs prior to the origin of modern birds. The study documents that color patterning within feathers and among feathers evolved earlier than previously believed. Further, these results indicate dinosaur feathers may have evolved for communication.

"Writing the first scientifically-based 'field guide' description of the appearance of an extinct dinosaur was a exciting and unforgettable experience — the ultimate dream of every kid who was ever obsessed with dinosaurs," Prum said. "Now that dream is really possible."

Yale University

Bird migration becoming more hazardous

2010-02-04T09:33:00.001+01:00

Can you imagine living your whole life in summer? In one of the most spectacular wildlife migrations on the planet, millions of shorebirds do exactly this by making a 20,000km round trip from their Arctic breeding grounds to wetlands in the southern hemisphere and then migrating north again each year.

Dr Richard Fuller from UQ's School of Biological Sciences is one of the researchers seeking to better understand the process .

“Australia is the end-point of one of these migration routes, the busy East Asian-Australasian Flyway, which connects us with a dozen Asian countries,” Dr Fuller said.

“This amazing wildlife spectacle is under threat.

"Some species using the flyway have declined enormously over the past couple of decades, with millions of birds being lost.

"Two of the commonest species (great knots and eastern curlews) are currently being considered for admission to the red list of species threatened with global extinction because they have declined so fast and so dramatically.

“What has caused these declines is not clear. There has been considerable loss of wetlands in Australia, but these appear not to be dramatic enough to explain the declines in migratory shore birds.”

But, according to Dr Fuller, there is another, more worrying possible explanation for the declines. During their migrations, the birds stop at “refuelling” sites in estuaries around the Yellow Sea, but these estuaries are rapidly disappearing because of land reclamation projects as the region undergoes an economic boom, he says.

“One of the biggest projects is at Saemangeum, South Korea, where construction of a 33km seawall has converted 40,000 hectares of prime estuarine habitat in to dry land," Dr Fuller said.

"It is estimated that approximately 100,000 birds could have been lost as a result of this development alone because they no longer have a place to refuel on their migration.”

“Conserving migratory animals is extremely hard because they fly across international borders. Robust international policies are needed to ensure protection of the whole migration route, because the whole system is only as strong as its weakest point.”

However, there is hope. Australia had signed bilateral agreements with Japan, China and South Korea aimed at protecting habitats for migratory birds, Dr Fuller said.

“The University of Queensland is working alongside Australian state and federal government to try and understand the causes of the birds' declines, and to discover solutions before it is too late to save one of the world's most spectacular migrations,” he said.

University of Queensland

Ancient crocodile relative likely food source for Titanoboa

2010-02-03T10:01:00.002+01:00

A 60-million-year-old relative of crocodiles described this week by University of Florida researchers in the Journal of Vertebrate Paleontology was likely a food source for Titanoboa, the largest snake the world has ever known. Working with scientists from the Smithsonian Tropical Research Institute in Panama, paleontologists from the Florida Museum of Natural History on the UF campus found fossils of the new species of ancient crocodile in the Cerrejon Formation in northern Colombia. The site, one of the world's largest open-pit coal mines, also yielded skeletons of the giant, boa constrictor-like Titanoboa, which measured up to 45 feet long. The study is the first report of a fossil crocodyliform from the same site.

"We're starting to flesh out the fauna that we have from there," said lead author Alex Hastings, a graduate student at the Florida Museum and UF's department of geological sciences.

Specimens used in the study show the new species, named Cerrejonisuchus improcerus, grew only 6 to 7 feet long, making it easy prey for Titanoboa. Its scientific name means small crocodile from Cerrejon.

The findings follow another study by researchers at UF and the Smithsonian providing the first reliable evidence of what Neotropical rainforests looked like 60 million years ago.

While Cerrejonisuchus is not directly related to modern crocodiles, it played an important role in the early evolution of South American rainforest ecosystems, said Jonathan Bloch, a Florida Museum vertebrate paleontologist and associate curator.

"Clearly this new fossil would have been part of the food-chain, both as predator and prey," said Bloch, who co-led the fossil-hunting expeditions to Cerrejon with Smithsonian paleobotanist Carlos Jaramillo. "Giant snakes today are known to eat crocodylians, and it is not much of a reach to say Cerrejonisuchus would have been a frequent meal for Titanoboa. Fossils of the two are often found side-by-side."

The concept of ancient crocodyliforms as snake food has its parallel in the modern world, as anacondas have been documented consuming caimans in the Amazon. Given the ancient reptile's size, it would have been no competition for Titanoboa, Hastings said.

Cerrejonisuchus improcerus is the smallest member of Dyrosauridae, a family of now-extinct crocodyliforms. Dyrosaurids typically grew to about 18 feet and had long tweezer-like snouts for eating fish. By contrast, the Cerrejon species had a much shorter snout, indicating a more generalized diet that likely included frogs, lizards, small snakes and possibly mammals.

"It seems that Cerrejonisuchus managed to tap into a feeding resource that wasn't useful to other larger crocodyliforms," Hastings said.

The study reveals an unexpected level of diversity among dyrosaurids, said Christopher A. Brochu, a paleontologist and associate professor in geosciences at the University of Iowa.

"This diversity is more evolutionarily complex than expected," said Brochu, who was not involved in the study. "A limited number of snout shapes evolved repeatedly in many groups of crocodyliforms, and it appears that the same is true for dyrosaurids. Certain head shapes arose in different dyrosaurid lineages independently."

Dyrosaurids split from the branch that eventually produced the modern families of alligators and crocodiles more than 100 million years ago. They survived the major extinction event that killed the dinosaurs but eventually went extinct about 45 million years ago. Most dyrosaurids have been found in Africa, but they occur throughout the world. Prior to this finding, only one other dyrosaurid skull from South America had been described.

Scientists previously believed dyrosaurids diversified in the Paleogene, the period of time following the mass extinction of dinosaurs, but this study reinforces the view that much of their diversity was in place before the mass extinction event, Brochu said. Somehow dyrosaurids survived the mass extinction intact while other marine reptile groups, such as mosasaurs and plesiosaurs, died out completely.

The crocodyliform's diminutive size came as a surprise, Hastings said, especially considering the giant reptiles that lived during the Late Cretaceous. The fossil record also points to the possibility of other types of ancient crocodyliforms inhabiting the same ecosystem. "In a lot of these tropical, diverse ecosystems in which crocodyliforms can thrive, you often see multiple snout types," he said. "They tend to start speciating into different groups."

University of Florida

DNA testing on 2,000-year-old bones in Italy reveal East Asian ancestry

2010-02-02T10:05:00.000+01:00

Researchers excavating an ancient Roman cemetery made a surprising discovery when they extracted ancient mitochondrial DNA (mtDNA) from one of the skeletons buried at the site: the 2,000-year-old bones revealed a maternal East Asian ancestry. The results will be presented at the Roman Archeology Conference at Oxford, England, in March, and published in the Journal of Roman Archaeology.

According to Tracy Prowse, assistant professor of Anthropology, and the lead author on the study, the isotopic evidence indicates that about 20% of the sample analyzed to-date was not born in the area around Vagnari. The mtDNA is another line of evidence that indicates at least one individual was of East Asian descent.

"These preliminary isotopic and mtDNA data provide tantalizing evidence that some of the people who lived and died at Vagnari were foreigners, and that they may have come to Vagnari from beyond the borders of the Roman Empire," says Prowse. "This research addresses broader issues relating to globalization, human mobility, identity, and diversity in Roman Italy."

Based on her work in the region, she thinks the East Asian man, who lived sometime between the first to second centuries AD—the early Roman Empire—was a slave or worker on the site. His surviving grave goods consist of a single pot (which archaeologists used to date the burial). What's more, his burial was disturbed in antiquity and someone was buried on top of him.

Prowse's team cannot say how recently he, or his ancestors, left East Asia: he could have made the journey alone, or his East Asian genes might have come from a distant maternal ancestor. However, the oxygen isotope evidence indicates that he was definitely not born in Italy and likely came here from elsewhere in the Roman Empire.

During this era, Vagnari was an Imperial estate owned by the emperor in Rome and controlled by a local administrator. Workers were employed in industrial activities on the site, including iron smelting and tile production. These tiles were used for roofing buildings on the site and were also used as grave covers for the people buried in the cemetery. Fragmentary tiles found in and around Vagnari are marked "Gratus Caesaris", which translates into "slave of the emperor."

In addition to the mystery the find uncovers, Prowse sees the broader scientific impact for archaeologists, physical anthropologists, and classicists: The grave goods from this individual's burial gave no indication that he was foreign-born or of East Asian descent.

"This multi-faceted research demonstrates that human skeletal remains can provide another layer of evidence in conjunction with archaeological and historical information," says Prowse.

McMaster University

With climate change, birds are taking off for migration sooner; not reaching destinations earlier

2010-02-01T10:29:00.000+01:00

Migrating birds can and do keep their travel dates flexible, a new study published online on January 28th in Current Biology, a Cell Press publication, reveals. But in the case of pied flycatchers, at least, an earlier takeoff hasn't necessarily translated into an earlier arrival at their destination. It appears the problem is travel delays the birds are experiencing as a result of harsh weather conditions on the final leg of their journey through Europe. The discovery may in a sense be good news as far as birds' potential to cope under climate change, but it also highlights the vulnerability of long-distance migrants to environmental conditions in general.

"We have been claiming for a while that migratory birds have difficulties in adapting to climate change because of their rigid and rather inflexible timing of spring migration; in Africa and South America, they cannot know when spring starts at their northern breeding grounds," said Christiaan Both of the University of Groningen in The Netherlands. "This study shows that timing of spring migration is flexible and that birds do respond to climate change, although in a rather indirect way: breeding dates have become progressively earlier, and birds are thus born earlier in the spring. We now show that the effect of early birth is also that the birds migrate early, and migration time has advanced over the last 25 years. The reason that the birds did not advance their arrival is thus not due to a failure to start migration earlier, but because circumstances at passage in Southern Europe have not improved."

Pied flycatchers are one of the best-studied migratory bird species in the world. With records going back more than 50 years, researchers have been able to investigate the birds' reaction to climate change over time. Pied flycatchers are also forest-dwelling, which makes them particularly interesting because of the strong seasonality in food dynamics in the forest.

"Forests are characterized by a short burst of insects rather early in spring," Both explained. "If the birds miss this insect peak for raising their chicks, they do not produce enough offspring to keep up their population sizes."

Like many migrants, pied flycatchers must tackle a rather remarkable and grueling trek each spring to reach their breeding sites. They spend their winters in Western Africa, anywhere from 5000 to 9000 kilometers from their breeding grounds across Europe and western Siberia. Their wintering grounds in Africa become progressively drier over the course of the season, and by the end of that dry spell, they somehow have to accumulate enough resources to fly about 2000 kilometers across the Sahara desert. The birds recover in Northern Africa before heading to their final destinations.

"Based on our calculations, they are covering the distance from Northern Africa to The Netherlands in about 6 days, and to central Sweden in about 12 days," Both said. Only a small fraction of birds make it through that harrowing journey. For those that do, "in some of the northern or eastern breeding grounds, the first birds often arrive when the breeding areas are still snow-covered. And these birds are strictly insectivorous—earlier arrival probably means death because there are not enough insects to be found." In The Netherlands, circumstances are better at arrival, he added, but the birds there get little or no chance to rest before breeding and nest building must begin. In most cases during the warm springs of the past decade, birds in The Netherlands have laid their first eggs 7 to 8 days after completing their journey.

Both's team found that the birds left their wintering grounds and made it all the way to Northern Africa 10 days earlier in the year in 2002 than they did in 1980. Still, they didn't arrive at their European breeding grounds any sooner.

The findings imply that "little should be expected in terms of an evolutionary response [to climate change]: any genetic variation in spring departure is likely to be masked by environmental constraints and not translated into earlier arrival," the researchers conclude. "More generally, because climate change often alters temperatures differently at different periods in the year, adaptation of life cycles in animals with a complex annual cycle is not likely to be solved by simple phenotypic or evolutionary responses toward earlier phenology. An adaptive evolutionary response most likely is needed on a whole suite of different traits simultaneously, and it remains to be seen whether evolution can alter species quickly enough to stop their decline."

Cell Press

History of Ice Cream Counts Over 5,000 Years

2010-01-29T10:00:00.002+01:00

The history of ice cream is rooted in ancient Asia, namely, China and Arabia. It was admired by Alexander of Macedonia, Napoleon, and George Washington, and patented by several people.

The researchers found that ice cream can be traced back to the 3rd century B.C. Chinese Emperor and his nobility were served concoctions of fruit juices with snow and ice. The recipes of the unusual dessert were kept secret, and were revealed only in the 9th century B.C.

There are references stating that cooled juices were very popular in the palace of the legendary King Solomon, and that the famous ancient Greek physician Hippocrates recommended ice cream for a better tonus and health improvement. Alexander Makedonsky was treated with ice cream during his trips to India and Persia.

Snow and ice were used in ancient Rome to prepare fruit drinks, for example, for the Roman emperor Nero (A.D. 37-68) who ordered ice to be brought from the mountains. Large ice cellars were built to preserve the frozen treat for extended periods of time.

There are a few interesting facts in ancient records in reference to ice cream. In 780 A.D., caliph al-Mahdi managed to deliver a supply of snow to Mecca using a train of camels. A Persian traveler Nassiri Khosrau mentioned in his writings that in 1040, the snow for beverages and ice cream was delivered to the table of the Cairo Sultan daily from the mountain regions of Syria.

Marco Polo, who traveled to China and tasted the icy dessert, is thought to have brought ice cream to Europe. When he came back to Italy from his trip, he shared some of the recipes with local chefs. In the middle of the 16th century, ice cream conquered France when Ekaterina Medici fell in love with this dessert. She treated her guests with ice cream at formal dinners and fed it to her son, Henry III.

Soon enough, ice cream migrated from Versailles to the households of French nobility despite strict prohibitions on recipe disclosure.

Many new varieties of ice cream were invented in France during the reign of Anne of Austria, Queen of France. In the middle of the 17th century, ice cream became available to ordinary mortals, and ice cream and ice beverages vendors flooded the streets of Paris. Later, Napoleon himself became an ice cream enthusiast.

Ice cream recipe came to the US in the 18th century along with the English immigrants. In 1700, Governor Bladen of Maryland, who was from England, served fruit ice cream and cooled beverages to his guests. Many US Presidents were fond of the cold dessert. George Washington himself used to prepare ice cream at his Mount Vernon estate.

Phillip Lenzi, an entrepreneur and chef, posted an ad in New York newspapers saying he brought recipes of different desserts from London, including the ice cream recipe. Soon ice cream acquired popularity among the residents of the East Coast.

With time, technologies of ice cream manufacturing were perfected. Ice cream cups were invented in France during the reign of Napoleon III (1852 — 1870). Assorted ice cream was first created in Italy, and chocolate was first added to the treat in Austria. In 1866, the guests at the Chinese ambassador reception in Paris were served an “omelet with surprise” designed by German chefs - an omelet with ginger ice cream inside. New ice cream varieties created for special occasions were later mass produced, especially in the US. The first ice cream factory was built in Baltimore, and soon similar factories appeared in New York, Washington, and Chicago.

Cooling equipment was also developing. A French engineer Ferdinand Carre invented the ammonia vapor-compression system in 1859. Mass production of refrigerators began in the second half of the 19th century. Later, special equipment for production and storage of ice was invented, which allowed for easier processing and lower price of ice cream.

In 1919, a teacher from Iowa designed a recipe and production technology of new ice cream variety covered with chocolate. On January 24, 1922 he was granted a patent for famous ice cream bar on a stick. The novelty was first called Eskimo pie, but later reduced to Eskimo. Meanwhile, the French claimed that this type of ice cream was created by one of their own in 1919. According to French sources, the name of this treat was created by accident in a movie theatre. One of the movie goers had too much ice cream while watching a film about Eskimos, and called the dessert “Eskimo.”

In Russia, since the old times people made their own version of milk-based ice cream. In Kievan Rus’, people enjoyed chipped frozen milk, and for the Pancake week they prepared a mixture of frozen cottage cheese, sugar, raisins and sour cream.

Milk-based ice cream was a part of the menu of Peter III and Katherine II. It was homemade and prepared in small quantities only . The first ice cream machine was introduced to Russia only in the 19th century, and commercial production of the dessert was commenced in the early 1930s.

Ice cream is now enjoyed by people all over the world, and is sold in nearly every grocery store. There are thousands of varieties of this cold, five thousand-year-old dessert.

Maksim Kondratyev

The color of dinosaur feathers identified

2010-01-28T11:18:00.002+01:00

The colour of some feathers on dinosaurs and early birds has been identified for the first time, reports a paper published in Nature this week. The research found that the theropod dinosaur Sinosauropteryx had simple bristles – precursors of feathers – in alternate orange and white rings down its tail, and that the early bird Confuciusornis had patches of white, black and orange-brown colouring. Future work will allow precise mapping of colours and patterns across the whole bird.

Mike Benton, Professor of Palaeontology at the University of Bristol, said, "Our research provides extraordinary insights into the origin of feathers. In particular, it helps to resolve a long-standing debate about the original function of feathers – whether they were used for flight, insulation, or display. We now know that feathers came before wings, so feathers did not originate as flight structures.

"We therefore suggest that feathers first arose as agents for colour display and only later in their evolutionary history did they become useful for flight and insulation."

The team of palaeontologists from the University of Bristol, UK, the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, University College Dublin and the Open University report two kinds of melanosomes found in the feathers of numerous birds and dinosaurs from the world-famous Jehol beds of NE China.

Melanosomes are colour-bearing organelles buried within the structure of feathers and hair in modern birds and mammals, giving black, grey, and rufous tones such as orange and brown. Because melanosomes are an integral part of the tough protein structure of the feather, they survive when a feather survives, even for hundreds of millions of years.

This is the first report of melanosomes found in the feathers of dinosaurs and early birds. It is also the first report of phaeomelanosomes in fossil feathers, the organelles that provide rufous and brown colours.

These discoveries confirm the substantial body of evidence that suggests birds evolved through a long line of theropod (flesh-eating) dinosaurs. It also demonstrates that the unique assemblage of characters that make a modern bird – feathers, wings, lightweight skeleton, enhanced metabolic system, enlarged brain and visual systems – evolved step-by-step over some 50 million years of dinosaur evolution, through the Jurassic and Cretaceous periods.

"These discoveries open up a whole new area of research", said Benton, "allowing us to explore aspects of the life and behaviour of dinosaurs and early birds that lived over 100 million years ago.

"Furthermore, we now know that the simplest feathers in dinosaurs such as Sinosauropteryx were only present over limited parts of its body – for example, as a crest down the midline of the back and round the tail – and so they would have had only a limited function in thermoregulation.

"Feathers are key to the success of birds and we can now dissect their evolutionary history in detail and see how each feather type – and the fine detail of feather structure – was acquired through time. This will link with current work on how the genome controls feather development."

University of Bristol

Lost Roman law code discovered in London

2010-01-27T11:05:00.002+01:00

Part of an ancient Roman law code previously thought to have been lost forever has been discovered by researchers at UCL's Department of History. Simon Corcoran and Benet Salway made the breakthrough after piecing together 17 fragments of previously incomprehensible parchment. The fragments were being studied at UCL as part of the Arts & Humanities Research Council-funded "Projet Volterra" – a ten year study of Roman law in its full social, legal and political context. Corcoran and Salway found that the text belonged to the Codex Gregorianus, or Gregorian Code, a collection of laws by emperors from Hadrian (AD 117-138) to Diocletian (AD 284-305), which was published circa AD 300. Little was known about the codex's original form and there were, until now, no known copies in existence.

"The fragments bear the text of a Latin work in a clear calligraphic script, perhaps dating as far back as AD 400," said Dr Salway. "It uses a number of abbreviations characteristic of legal texts and the presence of writing on both sides of the fragments indicates that they belong to a page or pages from a late antique codex book - rather than a scroll or a lawyer's loose-leaf notes.

"The fragments contain a collection of responses by a series of Roman emperors to questions on legal matters submitted by members of the public," continued Dr Salway. "The responses are arranged chronologically and grouped into thematic chapters under highlighted headings, with corrections and readers' annotations between the lines. The notes show that this particular copy received intensive use."

The surviving fragments belong to sections on appeal procedures and the statute of limitations on an as yet unidentified matter. The content is consistent with what was already known about the Gregorian Code from quotations of it in other documents, but the fragments also contain new material that has not been seen in modern times.

"These fragments are the first direct evidence of the original version of the Gregorian Code," said Dr Corcoran. "Our preliminary study confirms that it was the pioneer of a long tradition that has extended down into the modern era and it is ultimately from the title of this work, and its companion volume the Codex Hermogenianus, that we use the term 'code' in the sense of 'legal rulings'."

This particular manuscript may originate from Constantinople (modern Istanbul) and it is hoped that further work on the script and on the ancient annotations will illuminate more of its history.

University College London

Last Neanderthals died out 37,000 years ago

2010-01-27T10:55:00.002+01:00

The paper, by Professor João Zilhão and colleagues, builds on his earlier research which proposed that, south of the Cantabro-Pyrenean mountain chain, Neanderthals survived for several millennia after being replaced or assimilated by anatomically modern humans everywhere else in Europe. Although the reality of this 'Ebro Frontier' pattern has gained wide acceptance since it was first proposed by Professor Zilhão some twenty years ago, two important aspects of the model have remained the object of unresolved controversy: the exact duration of the frontier; and the causes underlying the eventual disappearance of those refugial Neanderthal populations (ecology and climate, or competition with modern human immigrants).

Professor Zilhão and colleagues now report new dating evidence for the Late Aurignacian of Portugal, an archaeological culture unquestionably associated with modern humans, that firmly constrains the age of the last Neanderthals of southern and western Iberia to no younger than some 37,000 years ago.

This new evidence therefore puts at five millennia the duration of the Iberian Neanderthal refugium, and counters speculations that Neanderthal populations could have remained in the Gibraltar area until 28,000 years ago.

These findings have important implications for the understanding of the archaic features found in the anatomy of a 30,000 year old child unearthed at Lagar Velho, Portugal. With the last of the Iberian Neanderthals dating to many millennia before the child was born, 'freak' crossbreeding between immediate ancestors drawn from distinct 'modern' and 'Neanderthal' gene pools cannot be a viable explanation. The skeleton's archaic features must therefore represent evolutionarily significant admixture at the time of contact, as suggested by the team who excavated and studied the fossil.

Professor Zilhão said: "I believe the 'Ebro frontier' pattern was generated by both climatic and demographic factors, as it coincides with a period of globally milder climate during which oak and pine woodlands expanded significantly along the west façade of Iberia.

"Population decrease and a break-up of interaction networks probably occurred as a result of the expansion of such tree-covered landscapes, favouring the creation and persistence of population refugia.

"Then, as environments opened up again for large herbivore herds and their hunters as a result of the return to colder conditions, interaction and movement across the previous boundary must have ensued, and the last of the Neanderthals underwent the same processes of assimilation or replacement that underpin their demise elsewhere in Europe five millennia earlier."

The dating was undertaken by experts at the University of Vienna (VERA laboratory) led by Professor Eva Maria Wild, and at the University of Oxford's Radiocarbon Accelerator Unit.

Professor Wild, head of the 14C program at VERA (Vienna Environmental Research Accelerator) said: "Accurate 14C dating was crucial for this study. For layer 2 of the cave sediment we achieved this by selecting teeth for 14C dating and by comparing the 14C results of the same sample after different, elaborate sample pre-treatments. Agreement between the results obtained with different methods provides a proof for accurate dating."

University of Bristol

World's least known bird rediscovered

2010-01-26T09:32:00.002+01:00

A species of bird, which has only been observed alive on three previous occasions since it was first discovered in 1867, has been rediscovered in a remote land corridor in north-eastern Afghanistan. The discovery was made as part of an international collaboration, which included researchers at the University of Gothenburg, Sweden. During the summer of 2008, the American ornithologist Robert J Timmins was commissioned by the American aid organisation USAID to compile an inventory of bird species in the Badakshan province in north-eastern Afghanistan. He managed to record the call of a species of bird that was as yet unknown.

Unheard birdsong

The recording found its way to the Swedish ornithologist Lars Svensson, who was quick to note that the recorded birdsong did not resemble that of any known species of bird. But from Timmins' description of the species, he soon began to suspect what kind of bird was on the recording.

Ornithological sensation

Lars Svensson and Urban Olsson at the Department of Zoology, University of Gothenburg, had in fact shown in a previous study that about a dozen stuffed birds in museum collections all around the world had been incorrectly classified: they were not of the common species of reed warbler the curators had assumed, but rather a far rarer species known as the Large-billed Reed Warbler (Acrocephalus orinus) - observed on just three documented occasions since 1867. In their previous study Svensson, Olsson and co-workers had pinpointed North-Eastern Afghanistan as an area where the Large-billed Reed Warbler probably bred in the 1930s. When both the Swedish colleagues heard the recording of the mysterious birdsong they realised that they were on the trail of an ornithological sensation.

World's least known bird

A year later, in June 2009, the Afghan ornithologists Naqeebullah Mostafawi, Ali Madad Rajabi and Hafizullah Noori from the Wildlife Conservation Society Afghanistan managed to travel to the Badakshan region, despite the war and ongoing clan conflicts. They used nets to capture 15 individuals of the mysterious species of bird. They sent photographs and feather samples to Lars Svensson and Urban Olsson, who used DNA analyses to confirm that after 142 years of searching, the breeding site of perhaps the world's least known bird had been found.

Under acute threat

News of the find was published this week in the journal Birding Asia and has aroused huge interest in ornithological circles. The Large-billed Reed Warbler is not hunted, but is regarded as being under acute threat since its breeding sites are being deforested by the local population in their hunt for fuel. "That's why it's vital that we protect both the species and its habitat now," says Urban Olsson.

University of Gothenburg

Exploring the Stone Age pantry

2010-01-25T10:38:00.002+01:00

The consumption of wild cereals among prehistoric hunters and gatherers appears to be far more ancient than previously thought, according to a University of Calgary archaeologist who has found the oldest example of extensive reliance on cereal and root staples in the diet of early Homo sapiens more than 100,000 years ago. Julio Mercader, holder of the Canada Research Chair in Tropical Archaeology in the U of C's Department of Archaeology, recovered dozens of stone tools from a deep cave in Mozambique showing that wild sorghum, the ancestor of the chief cereal consumed today in sub-Saharan Africa for flours, breads, porridges and alcoholic beverages, was in Homo sapiens' pantry along with the African wine palm, the false banana, pigeon peas, wild oranges and the African "potato." This is the earliest direct evidence of humans using pre-domesticated cereals anywhere in the world. Mercader's findings are published in the December 18 issue of the prestigious research journal Science.

"This broadens the timeline for the use of grass seeds by our species, and is proof of an expanded and sophisticated diet much earlier than we believed," Mercader said. "This happened during the Middle Stone Age, a time when the collecting of wild grains has conventionally been perceived as an irrelevant activity and not as important as that of roots, fruits and nuts."

In 2007, Mercader and colleagues from Mozambique's University of Eduardo Mondlane excavated a limestone cave near Lake Niassa that was used intermittently by ancient foragers over the course of more than 60,000 years. Deep in this cave, they uncovered dozens of stone tools, animal bones and plant remains indicative of prehistoric dietary practices. The discovery of several thousand starch grains on the excavated plant grinders and scrapers showed that wild sorghum was being brought to the cave and processed systematically.

"It has been hypothesized that starch use represents a critical step in human evolution by improving the quality of the diet in the African savannas and woodlands where the modern human line first evolved. This could be considered one of the earliest examples of this dietary transformation," Mercader said. "The inclusion of cereals in our diet is considered an important step in human evolution because of the technical complexity and the culinary manipulation that are required to turn grains into staples."

Mercader said the evidence is on par with grass seed use by hunter-gatherers in many parts of the world during the closing stages of the last Ice Age, approximately 12,000 years ago. In this case, the trend dates back to the beginnings of the Ice Age, some 90,000 years earlier.

University of Calgary

Humans Might Have Faced Extinction 1 Million Years Ago

2010-01-22T09:18:00.002+01:00

New genetic findings suggest that early humans living about one million years ago were extremely close to extinction.

The genetic evidence suggests that the effective population—an indicator of genetic diversity—of early human species back then, including Homo erectus, H. ergaster and archaic H. sapiens, was about 18,500 individuals (it is thought that modern humans evolved from H. erectus), says Lynn Jorde, a human geneticist at the University of Utah in Salt Lake City. That figure translates into a total population of 55,500 individuals, tops.

One might assume that hominin numbers were expanding at that time as fossil evidence shows that members of our Homo genus were spreading across Africa, Asia and Europe, Jorde says. But the current study by Jorde and his colleagues suggests instead that the population and, thus its genetic diversity, faced a major setback about one million years ago. The finding is detailed in the January 18 issue of Proceedings of the National Academy of Sciences.

To make these estimates, Jorde's group scanned two completely sequenced modern human genomes for a type of mobile element called Alu sequences. Alu sequences are short snippets of DNA that move between regions of the genome, though with such low frequency that their presence in a region suggests it is quite ancient. Because older Alu-containing regions have had time to accumulate more mutations, the team was also able to estimate the age of a region based on its nucleotide diversity. The team then compared the nucleotides in these old regions with the overall diversity in the two genomes to estimate differences in effective population size, and thus genetic diversity between modern and early humans.

"This is an original approach because they show that you can use mobile elements…to flag a region of the genome," says Cédric Feschotte, an evolutionary geneticist at the University of Texas Arlington.

The effective population researchers estimate at about 18,500 reveals that the extent of genetic diversity among hominins living one million years ago was between 1.7 and 2.9 times greater than among humans today. (Other studies have shown that the present-day effective population is around 10,000.) Jorde says the reason the modern effective population is so much smaller than the current number of people (nearly seven billion) is that a population explosion occurred, probably due to the development of agriculture about 10,000 years ago. He does not expect that there would have been such a staggering difference between the effective and actual populations of early humans.

Jorde thinks that the diminished genetic diversity one million years ago suggests human ancestors experienced a catastrophic event at that time as devastating as a purported supervolcano thought to have nearly annihilated humans 70,000 years ago. "We've gone through these cycles where we've had large population size but also where our population has been very, very small," he says.

National Academy of Sciences

Story of 4.5 million-year-old whale unveiled in Huelva

2010-01-20T09:12:00.001+01:00

In 2006, a team of Spanish and American researchers found the fossil remains of a whale, 4.5 million years old, in Bonares, Huelva. Now they have published, for the first time, the results of the decay and fossilisation process that started with the death of the young cetacean, possibly a baleen whale from the Mysticeti group. This is not the first discovery of the partial fossil remains of a whale from the Lower Pliocene (five million years ago) in the Huelva Sands sedimentary formation, but it is the first time that the results of the processes of fossilisation and fossil deposition following the death of a whale have been published.

The work of this international group, published in the latest issue of Geologica Acta, is the first taphonomic (fossilisation process) study done on cetacean remains combined with other paleontological disciplines such as ichnology (the study of trace fossils).

"Once the whale was dead, its body was at the mercy of scavengers such as sharks, and we know that one of these voracious attacks resulted in one of its fins being pulled off and moved about ten metres. It remained in this position in the deposit studied", Fernando Muñiz, one of the study's authors and a researcher in the University of Huelva's "Tectonics and Paleontology" research group, currently working as a palaeontologist for the City Council of Lepe, in Huelva, tells SINC.

The researchers have described the fossil remains discovered in Bonares, Huelva, at an altitude of 80 metres above sea level and 24 kilometres from the sea, and have studied the main taxonomic characteristics and associated fauna. The team also created a paleoenvironmental model to explain how the skeleton – which is incomplete apart from some pieces such as its three-metre-long hemimandibular jaw bones – was deposited.

The results show that these remains came from a "juvenile whale that died and became buried on the sea floor, at a depth of around 30-50 metres, and were subject to intense activity by invertebrate and vertebrate scavengers (as can be seen from the presence of numerous shark teeth associated with the bones)", says Muñiz. Based on the remains studied, it is hard for the researchers to say whether the cause of death was illness, old age, or attack by a larger predator.

In terms of its taxonomic description, the researchers say this is "difficult", although the morphology of the scapula (shoulder blade) suggests it is "from the Balaenopteridae (rorqual) family, belonging to the group of baleen whales from the Mysticeti sub-order", says the paleontologist.

Dead bodies as a source of nutrients

The occasional presence of a cetacean corpse on the sea floor represents an exceptional provision of nutrients for various ecological communities. According to recent studies of current-day phenomena, four ecological phases associated with whales have been recognised "that can be partially recognised in the fossil record" – the presence of mobile scavengers (sharks and bony fish), opportunists (especially polychaetes and crustaceans), sulphophilic extremophiles (micro organisms) and hard coral.

Once the bones deposited on the sea floor, free of organic material, were exposed, bivalve molluscs of the species Neopycnodonte cochlear colonised them. The presence of these bivalves suggests that the process to transform the biological remains after death was "relatively lengthy before it was definitively buried", explains the researcher.

"The fat and other elements resulting from the decomposition of the organic material would have enriched the sediment around and above the body, and this can be seen in the numerous burrowing structures in this sediment, created by endobiotic organisms, such as crustaceans and polychaete annelids", adds Muñíz. The bones were also "used", not only as a base to which these could attach themselves, but also as food.

According to the paleontologists, the presence of bioerosion structures indicates that the contents of the bones were used as an extraordinary source of nutrients, possibly by decapod crustaceans. This would be the first known evidence in the fossil record of a whale bone being consumed by decapod crustaceans with osteophagic feeding habits. The material is currently undergoing in-depth analysis by the authors of the study.

FECYT - Spanish Foundation for Science and Technology

'Smell of old books' offers clues to help preserve them

2010-01-19T09:33:00.003+01:00

Scientists may not be able to tell a good book by its cover, but they now can tell the condition of an old book by its smell. In a report in ACS' Analytical Chemistry, a semi-monthly journal, they describe development of a new test that can measure the degradation of old books and precious historical documents based on their smell. The nondestructive "sniff" test could help libraries and museums preserve a range of prized paper-based objects, some of which are degrading rapidly due to advancing age, the scientists say. Matija Strlic and colleagues note in the new study that the familiar musty smell of an old book, as readers leaf through the pages, is the result of hundreds of so-called volatile organic compounds (VOCs) released into the air from the paper. Those substances hold clues to the paper's condition, they say. Conventional methods for analyzing library and archival materials involve removing samples of the document and then testing them with traditional laboratory equipment. But this approach destroys part of the document.

The new technique, called "material degradomics," analyzes the gases emitted by old books and documents without altering the documents themselves. They used it to "sniff" 72 historical papers from the 19th and 20th centuries, including papers containing rosin (pine tar) and wood fiber, which are the most rapidly degrading paper types in old books. The scientists identified 15 VOCs that seem good candidates as markers to track the degradation of paper in order to optimize their preservation. The method also could help preserve other historic artifacts, they add.

credited to American Chemical Society

Late-surviving megafauna exposed by ancient DNA in frozen soil

2010-01-18T11:01:00.001+01:00

Extinct woolly mammoths and ancient American horses may have been grazing the North American steppe for several thousand years longer than previously thought. After plucking ancient DNA from frozen soil in central Alaska, a team of researchers used cutting-edge techniques to uncover "genetic fossils" of both species locked in permafrost samples dated to between 7,600 and 10,500 calendar years. This new evidence suggests that at least one population of these now-extinct mammals endured longer in the continental interior, challenging the conventional view that these and other large species, or megafauna, disappeared from the Americas about 12,000 years ago. "We don't know how long it takes to pinch out a species," says Ross MacPhee, Curator of Mammalogy at the American Museum of Natural History. "Extinctions often seem dramatic and sudden in fossil records, but our study provides an idea of what an extinction event might look like in real time, with imperiled species surviving in smaller and smaller numbers until eventually disappearing completely."

At the end of the Pleistocene, the geological epoch roughly spanning 12,000 to 2.5 million years ago, many of the world's megafauna, such as giant sloths, saber-toothed cats, dire wolves, stag-moose, and mammoths, vanish from the geological record. Some large species such as Equus caballus, the species from which the domestic horse derives, became extinct in North America but persisted in small populations elsewhere. Because of the apparent sudden disappearance of many megafaunal species in North America, some scientists have proposed cataclysmic explanations like human overhunting, an extraterrestrial impact, and the introduction of novel infectious diseases. The swiftness of the extinctions, however, is not suggested directly by the fossils themselves but is inferred from radiocarbon dating of bones and teeth discovered on the surface or buried in the ground. Current "macrofossil" evidence places the last-known mammoths and wild horses between 13,000 and 15,000 years ago.

But hard remains of animals are rarely preserved, difficult to find, and laborious to accurately date because of physical degradation. Because of this, MacPhee and co-authors Eske Willerslev of the University of Copenhagen in Denmark, Richard Roberts of the University of Wollongong in Australia, and Duane Froese of the University of Alberta in Canada decided to tackle the problem by dating the "last survivors" through dirt. Frozen sediments from the far north of Siberia and Canada can preserve small fragments of animal and plant DNA exceptionally well, even in the complete absence of any visible organic remains, such as bone or wood.

"In principle, you can take a pinch of dirt collected under favorable circumstances and uncover an amazing amount of forensic evidence regarding what species were on the landscape at the time," says Willerslev, director of the Centre for GeoGenetics at the University of Copenhagen. "The use of ancient DNA offers the possibility of being able to sample previous life within the last 400,000 years, freeing us from having to rely on skeletal and other macrofossil evidence as the only way to collect information about species that are no longer with us."

In order to prospect for genetic fossils, the team collected soil cores from undisturbed Alaskan permafrost. Wind-blown Stevens Village, situated on the bank of the Yukon River, fit the bill perfectly. Here, sediments were sealed in permafrost soon after deposition. Two independent methods (radiocarbon and optically stimulated luminescence) were used to date plant remains and individual mineral grains found in the same layers as the DNA.

"With these two techniques, we can be confident that the deposits from which the DNA was recovered haven't been contaminated since these lost giants last passed this way," said Roberts, director of the Centre for Archaeological Science at the University of Wollongong. "It's a genetic graveyard, frozen in time."

Cores collected at Stevens Village offer a clear picture of the local Alaskan fauna at the end of the last ice age. The oldest sediments, dated to about 11,000 years ago, contain remnant DNA of Arctic hare, bison, and moose; all three animals were also found in higher, more recent layers, as would be expected. But one core, deposited between 7,600 and 10,500 years ago, confirmed the presence of both mammoth and horse DNA. To make certain that the integrity of this sample had not been compromised by geologic processes (for example, that ancient DNA had not blown into the surface soils), the team did extensive surface sampling in the vicinity of Stevens Village. No DNA evidence of mammoth, horse, or other extinct species was found in modern samples, a result that supports previous studies which have shown that DNA degrades rapidly when exposed to sunlight and various chemical reactions.

"The fact that we scored with only one layer is not surprising," says MacPhee. "When you start going extinct, there will be fewer and fewer feet on the ground, and thus less and less source material for ancient DNA such as feces, shed dermal tissues, and decaying bodies."

The team also developed a statistical model to show that mammoth and horse populations would have dwindled to a few hundred individuals by 8,000 years ago.

"At this point, mammoths and horses were barely holding on. We may actually be working with the DNA of some of the last members of these species in North America," says permafrost expert Froese, associate professor in the Department of Earth and Atmospheric Sciences at the University of Alberta. "The Yukon Flats includes large shifting river bars with an abundance of high quality forage where large mammals can and could make a living. There may have been a handful of similar sites in Alaska, hosting small remnant populations," says Froese.

"Dirt DNA has lots of exciting potential to contribute to extinction debates in other parts of the world too, as well as a range of archaeological questions," said Willerslev, who also points out that the approach is not restricted to looking back at the past. "We can also use it to make a list of modern species living in any particular location," he said. "This kind of information is really valuable for studies of animals that are hard to detect, and there are some neat forensic applications too."

American Museum of Natural History

Ancient eyeliner guard against bacteria

2010-01-13T10:21:00.000+01:00

Egyptian women in ancient times may have worn thick eyeliner to guard against bacterial infection, French scientists said.

Scientists at the University of Pierre and Marie Curie tested lead-based substances found in eye makeup from the time of the pharaohs. The makeup had been preserved at the Louvre museum in Paris.

When cultured on human skin cells, the lead-based substances, which contained the mineral laurionite, boosted production of nitric oxide by as much as 240 percent, the scientists wrote in this week's issue of the journal Analytic Chemistry.

Nitric oxide is a signaling agent that strengthens the immune system to fight disease, researcher Christian Amatore and his colleagues wrote of their study. Bacterial eye infections are common in people living around tropical marshes, such as those of the river Nile, Amatore said.

The findings show why ancient Egyptians could have believed the makeup had magical properties, the researchers said.

UPI

Egypt discovers new workers' tombs near pyramids

2010-01-12T12:02:00.003+01:00

Egyptian archaeologists discovered a new set of tombs belonging to the workers who built the great pyramids, shedding light on how the laborers lived and ate more than 4,000 years ago, the antiquities department said Sunday.

The thousands of men who built the last remaining wonder of the ancient world ate meat regularly, worked in three months shifts and were given the honor of being buried in mud brick tombs within the shadow of the sacred pyramids they worked on.

The newly discovered tombs date to Egypt's 4th Dynasty (2575 B.C. to 2467 B.C.) when the great pyramids were built, according to the head of Egypt's Supreme Council of Antiquities, Zahi Hawass.

Graves of the pyramid builders were first discovered in the area in 1990, he said, and discoveries such as these show that the workers were paid laborers, rather than the slaves of popular imagination.

"These tombs were built beside the king's pyramid, which indicates that these people were not by any means slaves," said Hawass in the statement. "If they were slaves, they would not have been able to build their tombs beside their king's."

Evidence from the site, Hawass said, indicates that the approximately 10,000 laborers working on the pyramids ate 21 cattle and 23 sheep sent to them daily from farms in northern and southern Egypt.

He added that the workers were rotated every three months and the burial sites were for those who died during the construction.

Discoveries like these reveal other aspects of ancient Egyptian society besides just the stone monuments and temples frequented by priests, rulers and nobles, explained Salima Ikram, a professor of Egyptology at the American University in Cairo.

"It is important to find tombs that belong to lower class people that are not made out of stone that tell you about the social organization and the relative wealth of a range of people," she said.

Workers' tombs from the 4th Dynasty were typically made of mud bricks and shaped like cones and covered in white plaster, probably echoing the nearby limestone-clad pyramids of the kings.

The most important new tomb discovered, according to Hawass, belonged to a man named Idu and the statement described it as rectangular in structure, with a plaster covered mud brick outside casing.

The tomb also featured burial shafts encased in white limestone.

Further grave sites were found around the main tomb, including burial shafts containing skeletons and clay pots.

yahoo.news

30,000-year-old teeth shed new light on human evolution

2010-01-11T11:35:00.000+01:00

The teeth of a 30,000-year-old child are shedding new light on the evolution of modern humans, thanks to research from the University of Bristol published this week in PNAS. The teeth are part of the remarkably complete remains of a child found in the Abrigo do Lagar Velho, Portugal and excavated in 1998-9 under the leadership of Professor João Zilhão of the University of Bristol. Classified as a modern human with Neanderthal ancestry, the child raises controversial questions about how extensively Neanderthals and modern human groups of African descent interbred when they came into contact in Europe.

'Early modern humans', whose anatomy is basically similar to that of the human race today, emerged over 50,000 years ago and it has long been the common perception that little has changed in human biology since then.

When considering the biology of late archaic humans such as the Neanderthals, it is thus common to compare them with living humans and largely ignore the biology of the early modern humans who were close in time to the Neanderthals.

With this in mind, an international team, including Professor Zilhão, reanalysed the dentition of the Lagar Velho child (all of its deciduous – milk – teeth and almost all of its permanent teeth) to see how they compared to the teeth of Neanderthals, later Pleistocene (12,000-year-old) humans and modern humans.

Employing a technique called micro-tomography which uses x-rays to create cross-sections of 3D-objects, the researchers investigated the relative stages of formation of the developing teeth and the proportions of crown enamel, dentin and pulp in the teeth.

They found that, for a given stage of development of the cheek teeth, the front teeth were relatively delayed in their degree of formation. Moreover, the front teeth had a greater volume of dentin and pulp but proportionally less enamel than the teeth of recent humans.

The teeth of the Lagar Velho child thus fit the pattern evident in the preceding Neanderthals, and contrast with the teeth of later Pleistocene (12,000-year-old) humans and living modern humans.

Professor Zilhão said: "This new analysis of the Lagar Velho child joins a growing body of information from other early modern human fossils found across Europe (in Mladeč in the Czech Republic, Peştera cu Oase and Peştera Muierii in Romania, and Les Rois in France) that shows these 'early modern humans' were 'modern' without being 'fully modern'. Human anatomical evolution continued after they lived 30,000 to 40,000 years ago."

University of Bristol

Researchers recalculate age of Solar System

2010-01-05T08:51:00.002+01:00

Lead-lead (Pb-Pb) dating is among the most widely used radiometric dating techniques to determine the age of really old things, such as the age of the Earth or the Solar System. However, recent advances in instrumentation now allow scientists to make more precise measurements that promise to revolutionize the way the ages of some samples are calculated with this technique.

Radiometric dating can be used to determine the age of a wide range of natural and human-made materials. The comparison between the observed abundance of a naturally occurring radioactive isotope, such as uranium (U), and its decay products can be used to determine the age of a material, using known decay rates. The Pb-Pb dating technique has been used for decades under the assumption that the ratio of the 238U and 235U isotopes, both of which decay to different isotopes of Pb, is constant in the Solar System. This assumed value is built into the Pb-Pb age equation.

According to research published online in the Dec. 31 issue of Science Express and in the Jan. 22 issue of Science magazine by Greg Brennecka, a graduate student in the School of Earth and Space Exploration (SESE) at Arizona State University (ASU), the 238U/235U ratio can no longer be considered a constant in meteoritic material. Any deviation from this assumed value causes miscalculation in the determined Pb-Pb age of a sample, meaning that the age of the Solar System could be miscalculated by as much as several million years. Although this is a small fraction of the 4.57 billion year age of the Solar System, it is significant since some of the most important events that shaped the Solar System occurred within the first 10 million years of its formation.

Brennecka and colleagues at ASU and at the University of Frankfurt, Germany, measured the 238U/235U ratio in the earliest solids in the Solar System, calcium-aluminum-rich inclusions (CAIs). CAIs were the first solids to condense from the cooling protoplanetary disk during the birth of the Solar System. The absolute ages of the CAIs, determined through Pb-Pb dating, are generally considered to date the origin of the Solar System. The high-precision data they obtained from CAIs of the Allende meteorite showed that the 238U/235U ratio is not the same in all CAIs.

"This variation implies substantial uncertainties in the ages previously determined by Pb-Pb dating of CAIs," explains Brennecka. "This will likely make U isotope measurements part of the procedure for Pb-Pb dating, as the 238U/235U ratio can no longer be assumed to be invariant."

Brennecka began to think about the idea that the U isotope ratio might not be constant in meteoritic material after learning about work done by Professor Stefan Weyer of the Goethe University of Frankfurt during a sabbatical visit to ASU the previous year. Weyer spent a semester at ASU developing a technique to measure natural variation of U isotopes in Earth and planetary materials, working in the state-of-the-art laboratories of Ariel Anbar, a professor in SESE and ASU's College of Liberal Arts and Science's Department of Chemistry & Biochemistry, and in the W. M. Keck Foundation Laboratory for Environmental Biogeochemistry. That work revealed measurable differences in 238U/235U in different environments on Earth, when everyone thought the ratio was invariant in everything on Earth and our Solar System.

At this time, Brennecka was taking a class on meteorites and the origin of the Solar System from Meenakshi Wadhwa, a professor in the School of Earth and Space Exploration and director of the ASU Center for Meteorite Studies. For a class assignment, Brennecka developed a research proposal centered on the implications of variable U isotopes in early Solar System materials. Anbar and Wadhwa encouraged him to take the proposal from the classroom to the laboratory.

"This project is a prime example of what's possible as a result of the unusual culture of collaboration and cross-fertilization that exists in SESE, and at ASU in general," says Anbar. "It is also a direct result of ASU's investments in world-class laboratory facilities for Earth and planetary sciences. Those facilities were critical for Greg's measurements, and also sparked the collaboration with Stefan Weyer's group that started us down this research path."

Brennecka worked with Anbar and Wadhwa to refine the procedures at ASU to be able to measure 238U/235U in the extremely small CAIs, using Wadhwa's lab and instruments in the ASU Center for Meteorite Studies. Eleven of the thirteen CAIs were from the ASU Center for Meteorite Studies collection; the other two were from the Senckenberg Museum collection in Frankfurt. The project was supported by the National Aeronautics and Space Administration (NASA), including the NASA Origins of Solar Systems Program, and the NASA Astrobiology Institute (NAI). ASU is home to one of 14 research teams from across the country that comprise the NAI which explores the origin, evolution, distribution, and future of life on Earth and in the universe.

"We started with CAIs because the Pb-Pb age of those materials is considered the start of the Solar System, so that is one of the most important dates for the cosmochemistry community, and it should be as accurate as possible," explains Brennecka. "Because this was a very new area of research and to ensure accurate results, we talked with Stefan, who was then back in Frankfurt, to set up a collaborative effort for laboratory comparison on the results. We shared samples and standards and independently ran tests to see if we got the same answer, which we did."

The U isotope ratios in all but two CAIs differed significantly from the standard "assumed" value. One of the possible mechanisms that could have produced these U isotope variations in meteorites is the decay of extant 247Cm to 235U. 247Cm is created during only certain types of supernovae and has a very short half-life (15.6 million years) compared to the age of the Solar System, so all of the 247Cm that was present originally has since completely decayed away. Brennecka and colleagues performed additional tests to determine if this was the cause of the U isotope variation.

If a correlation existed between the 238U/235U values and the original Cm/U in the CAIs, it would provide evidence that 247Cm was the reason for the 238U/235U variations. Since 235U is from the decay of 247Cm, higher Cm/U ratios mean there is relatively more 235U produced from 247Cm decay. As Cm has no long-lived stable isotope, the initial Cm/U ratio of a sample cannot be directly determined, so geochemical proxies were used. The correlation of these proxies, or elements that behave like Cm, with U isotope ratios in the CAIs provided strong evidence for the presence of extant 247Cm in the early Solar System. The 238U/235U ratios Brennecka obtained from the Allende meteorite were used to quantify the amount of 247Cm present in the early Solar System.

"Cosmochemists have searched for evidence for live 247Cm in the early Solar System for decades, and this is the first time that its presence has been demonstrated definitively. This work not only impacts precise and accurate dating of the earliest events to occur in our Solar System, but it also has broader implications for the environment and conditions in which our Solar System was born," explains Wadhwa.

"It is possible that in the future we will be able to use the 247Cm-235U system as a short-lived chronometer," says Brennecka. "But most importantly in the short term, this will help improve the accuracy of Pb-Pb dating."

Arizona State University

Ancient Mayans Had Toilets, Fountains

2009-12-28T09:47:00.000+01:00

Ancient Mayans and toilets: Scientists have uncovered elaborate subterranean aqueducts built to take advantage of the spring-fed streams at the ancient Mexican city of Palenque.

Ancient Mayans had toilets, fountains and created other sources of running water, according to a recent study.

Kirk French, an archaeologist, and his colleague Christopher Duffy, a hydrologist, both from Pennsylvania State University, detailed their findings this month in the Journal of Archaeological Science.

According to their studies, the ancient Mayans had the skills and ability not only to pull running water into their villages, but to have created fountains and toilets by controlling water flow.

Scientists have uncovered elaborate subterranean aqueducts built to take advantage of the spring-fed streams at the ancient Mexican city of Palenque

They believe the Mayans had discovered how to control water pressure and use it to create running water in their palaces around 750 AD.

This belief was reinforced by the discovery of a buried conduit nearly 216 feet in length located on a steep slope that narrows sharply at the end of the spot where the water flows into. Researchers calculate that the water pressure as it flowed downward could have created an arc nearly 20 feet high as part of a spectacular fountain, or to push running water through their palaces.

The further discovery of ceramic tubes, likely used to direct running water, puts the Mayans at the top of the engineering pile.

postchronicles and youtube

Modern behavior of early humans found half-million years earlier than previously thought

2009-12-23T10:01:00.002+01:00

Evidence of sophisticated, human behavior has been discovered by Hebrew University of Jerusalem researchers as early as 750,000 years ago – some half a million years earlier than has previously been estimated by archaeologists. The discovery was made in the course of excavations at the prehistoric Gesher Benot Ya'aqov site, located along the Dead Sea rift in the southern Hula Valley of northern Israel, by a team from the Hebrew University Institute of Archaeology. Analysis of the spatial distribution of the findings there reveals a pattern of specific areas in which various activities were carried out. This kind of designation indicates a formalized conceptualization of living space, requiring social organization and communication between group members. Such organizational skills are thought to be unique to modern humans.

Attempts until now to trace the origins of such behavior at various prehistoric sites in the world have concentrated on spatial analyses of Middle Paleolithic sites, where activity areas, particularly those associated with hearths, have been found dating back only to some 250,000 years ago.

The new Hebrew University study, a report on which is published this week in Science magazine, describes an Acheulian (an early stone tools culture) layer at Gesher Benot Ya'aqov that has been dated to about 750,000 years ago. The evidence found there consists of numerous stone tools, animal bones and a rich collection of botanical remains.

Analyses of the spatial distribution of all these finds revealed two activity areas in the layer: the first area is characterized by abundant evidence of flint tool manufacturing. A high density of fish remains in this area also suggests that the processing and consumption of many fish were carried out in this area -- one of the earliest evidences for fish consumption by prehistoric people anywhere.

In the second area, identified evidence indicates a greater variation of activities – all of which took place in the vicinity of a hearth. The many wood pieces found in this area were used as fuel for the fire. Processing of basalt and limestone was spatially restricted to the hearth area, where activities indicate the use of large stone tools such as hand axes, chopping tools, scrapers, and awls. The presence of stone hammers, and in particular of pitted anvils (used as nutting stones), suggest that nut processing was carried out near the hearth and may have involved the use of nut roasting. In addition, fish and crabs were probably consumed near the hearth.

The Hebrew University of Jerusalem

Poisonous prehistoric 'raptor' discovered by research team from Kansas and China

2009-12-22T09:47:00.002+01:00

A group of University of Kansas researchers working with Chinese colleagues have discovered a venomous, birdlike raptor that thrived some 128 million years ago in China. This is the first report of venom in the lineage that leads to modern birds. "This thing is a venomous bird for all intents and purposes," said Larry Martin, KU professor and curator of vertebrate paleontology at the Natural History Museum and Biodiversity Institute. "It was a real shock to us and we made a special trip to China to work on this."

The KU-China team's findings will be published in the early edition of the Proceedings of the National Academy of Sciences during the week of Dec. 21.

"We think it's going to make a big splash," said Martin.

The article's authors are Enpu Gong, geology department at Northeastern University in Shenyang, China, and researchers Martin, David Burnham and Amanda Falk at the KU Natural History Museum and Biodiversity Institute.

The dromaeosaur or raptor, Sinornithosaurus (Chinese-bird-lizard), is a close relative to Velociraptor. It lived in prehistoric forests of northeastern China that were filled with a diverse assemblage of animals including other primitive birds and dinosaurs.

"This is an animal about the size of a turkey," said Martin. "It's a specialized predator of small dinosaurs and birds. It was almost certainly feathered. It's a very close relative of the four-winged glider called Microraptor."

The venom most likely sent the victim into rapid shock, shrinking the odds of retaliation, escape or piracy from other predators while the raptor manipulated its prey.

"You wouldn't have seen it coming," said Burnham. "It would have swooped down behind you from a low-hanging tree branch and attacked from the back. It wanted to get its jaws around you. Once the teeth were embedded in your skin the venom could seep into the wound. The prey would rapidly go into shock, but it would still be living, and it might have seen itself being slowly devoured by this raptor."

The genus had special depressions on the side of its face thought by the investigators to have housed a poison gland, connected by a long lateral depression above the tooth row that delivered venom to a series of long, grooved teeth on the upper jaw. This arrangement is similar to the venom-delivery system in modern rear-fanged snakes and lizards. The researchers believe it to be specialized for predation on birds.

"When we were looking at Sinornithosaurus, we realized that its teeth were unusual, and then we began to look at the whole structure of the teeth and jaw, and at that point, we realized it was similar to modern-day snakes," Martin said.

Sinornithosaurus is represented by at least two species. These specimens have features consistent with a primitive venom-delivery system. The KU-China research team said it was a low-pressure system similar to the modern Beaded lizard, Heloderma, however the prehistoric Sinornithosaurus had longer teeth to break through layers of feathers on its bird victims.

The discovery of features thought to be associated with a venom-delivery system in Sinornithosaurus stemmed from a study of the anatomy and ecology of Microraptor by the joint Chinese-KU team. They now are seeking to discover if Microraptor may have possessed a similar poison-delivery system.

University of Kansas

Valley in Jordan Inhabited and Irrigated for 13,000 Years

2009-12-18T11:38:00.002+01:00

You can make major discoveries by walking across a field and picking up every loose item you find. Dutch researcher Eva Kaptijn succeeded in discovering -- based on 100,000 finds -- that the Zerqa Valley in Jordan had been successively inhabited and irrigated for more than 13,000 years. But it was not just communities that built irrigation systems: the irrigation systems also built communities.

Archaeologist Eva Kaptijn has given up digging in favour of gathering. With her colleagues, she has been applying an intensive field exploration technique: 15 metres apart, the researchers would walk forward for 50 metres. On the outward leg, they'd pick up all the earthenware and, on the way back, all of the other material. This resulted in more than 100,000 finds, varying from about 13,000 years to just a few decades old.

Based on further research on the finds and where they were located, Kaptijn succeeded in working out the extent of habitation in the Zerqa Valley in Jordan over the past millennia. The area where she undertook her research is also called the Zerqa Triangle; it is bounded by the River Zerqa and forms part of the Jordan Valley. The area covers roughly 72 square kilometres. Kaptijn discovered that the triangle had been inhabited, on and off, for thousands of years, but that this habitation was always highly dependent on the irrigation methods used by those who lived there. While the soil in the valley is very rich, there was usually not enough rainfall to cultivate plants without some additional irrigation.

Irrigation shapes the community

The irrigation methods exerted a major influence on the people who lived in the valley; power was often dependent on controlling the allocation of water. Kaptijn discovered that the type of irrigation system could result in a community of internally egalitarian tribes, with these tribes being linked to each other in a strict, hierarchical order. At other times, the valley was actually dominated by a large-scale, almost capitalist cultivation of sugar cane. Eva Kaptijn's research is part of the multi-disciplinary project Settling the Steppe. The Archaeology of changing societies in Syro-Palestinian drylands during the Bronze and Iron Ages. This project is funded by the NWO's Open Competition scheme.

Arne Wosskink received his doctorate within the same project on 28 October 2009.

NWO (Netherlands Organization for Scientific Research) (2009, December 18). Valley in Jordan inhabited and irrigated for 13,000 years. ScienceDaily. Retrieved December 18, 2009, from http://www.sciencedaily.com/releases/2009/12/091215155956.htm?utm_source=feedburner&utm_medium=feedutm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29

Sea level rise may exceed worst expectations

2009-12-17T09:18:00.003+01:00

Seas were nearly 10 metres higher than now in previous interglacial period.

With climate talks stalling in Copenhagen, a study suggests that one problem, sea level rise, may be even more urgent than previously thought.

Robert Kopp, a palaeoclimatologist at Princeton University in New Jersey, and his colleagues examined sea level rise during the most recent previous interglacial stage, about 125,000 years ago. It was a time when the climate was similar to that predicted for our future, with average polar temperatures about 3-5°C warmer than now.

Other studies have looked at this era, but most focused on sea level changes in only a few locales and local changes may not fully reflect global changes. Sea level can rise, for example, if the land is subsiding. It can also be affected by changes in the mass distribution of Earth. For example, says Kopp, ice-age glaciers have enough gravity to pull water slightly polewards. When the glaciers melt, water moves back towards the Equator. To adjust for such effects, Kopp's team compiled sea-level data from over 30 sites across the globe.

"We could go to a lot of different places and look at coral reefs or intertidal sediments or beaches that are now stranded above sea level, and build a reasonably large database of sea-level indicators," says Kopp.

The team reports in Nature today that the sea probably rose about 6.6–9.4 metres above present-day levels during the previous period between ice ages. When it was at roughly its present level, the average rate of rise was probably 56–92 centimetres a century. "[That is] faster than the current rate of sea level rise by a factor of about two or three," Kopp says, warning that if the poles warm as expected, a similar accelleration in sea-level rise might occur in future.

Climate meltdown

The study is "very sophisticated", says Peter Clark, a geologist at Oregon State University in Corvallis. "A lot more of the existing ice sheets at the time must have melted than was thought to be the case," he says, such as parts of Greenland and Antarctica.

The implications are disconcerting, says Clark. If the world warms up to levels comparable to those 125,000 years ago, "we can expect a large fraction of the Greenland ice sheet and some part of the Antarctic ice sheet, mostly likely West Antarctica, to melt. That's clearly in sight with where we're heading."

Jonathan Overpeck, a climate scientist at the University of Arizona in Tucson agrees. "Earth's polar ice sheets may be more vulnerable to climate change than commonly believed," he says.

Furthermore, even if global warming causes seas to start rising toward the levels seen 125,000 years ago, there is no reason to presume that it will proceed at the relatively sedate rate of 6-9 millimeters a year seen by Kopp's study. In part, that's because his study didn't have the resolution to spot changes on a year-by-year basis, so there's nothing to say that the rise during the last interglacial didn't occur in shorter, faster spurts, undetectable in Kopp's data.

Near future warming will also be driven by potentially faster-moving processes than those of the last interglacial. "The driver of [climate change during the last interglacial period] was slow changes in Earth's orbit, happening over thousands of years," says Stefan Rahmstorf, an ocean scientist at the Potsdam Institute for Climate Impact Research in Germany. "We're now set to cause several degrees of global warming within just a century. I would expect this to drive a much faster sea level rise."

Some scientists think that we may already be committed to a future with higher seas than had been expected. "There could be a global warming tipping point beyond which many metres of sea level rise is inevitable unless global greenhouse-gas emissions are cut dramatically, and soon," warns Overpeck.

"I have spent a lot of time talking with national security decision-makers in this country and abroad about the security implications of climate change," says Marc Levy, deputy director of the Center for International Earth Science Information Network at Columbia University's Earth Institute in New York. "I've consistently witnessed an inability on their part to take sea-level risks seriously. This study helps frame the risks in ways that decision-makers can better understand."

nature.com

Unique Siberian mammoth specimen insured for 1 million euros

2009-12-16T08:48:00.002+01:00

A 40,000-year-old baby woolly mammoth specimen found on Russia's Yamal Peninsula is being insured for 1 million euros ($1.47 million) before going on an international museum tour, AlfaStrakhovanie Group said on Monday.

Known as Lyuba, the 50-kg (110-pound) female mammoth will be the star attraction at Chicago's Field Museum from March 2010. The Mammoths and Mastodons: Titans of the Ice Age exhibit will then go on a 10-city tour that ends at London's Natural History Museum in 2014.

Lyuba is usually on display at the regional museum in Salekhard in the Yamal-Nenets Autonomous Area, where she was discovered by reindeer herders in 2007. The unique specimen is currently undergoing preservation works at the Russian Academy of Sciences' Zoological Institute in St. Petersburg that will allow her to be displayed without refrigeration.

Scientists estimate the baby mammal was about a month old when she died after getting stuck in mud on a riverbank. The carcass was remarkably well-preserved, with eyes and trunk almost intact and even some fur remaining on its skin.

Mammoths, giant mammals known for their furry coats, huge tusks and massive bulk, are thought to have appeared some 4.8 million years ago and be close relatives of modern-day elephants.

While most woolly mammoths died out approximately 12,000 years ago, its dwarf version survived on Russia's Wrangel Island, located in the Arctic Ocean, up until 1700 BC.

Well-preserved mammoth remains have been found all across Siberia.

RIA Novosti

Story of 4.5 million-year-old whale unveiled in Huelva

2009-12-16T08:40:00.002+01:00

Dead bodies as a source of nutrients

credited to FECYT - Spanish Foundation for Science and Technology

Scientist uncovers relics of ancient cosmos

2009-12-15T08:35:00.002+01:00

A University of Manchester scientist, working as part of an international team, has uncovered an unexpectedly rich trove of relicts from the ancient cosmos.

Dr Henner Busemann from The School of Earth, Atmospheric and Environmental Sciences has uncovered minute grains in stratospheric dust that may have formed inside stars that lived and died long before the birth of our sun.

Dust samples collected by high-flying aircraft in the upper atmosphere have also yielded material from molecular clouds in interstellar space, reports Dr Busemann and colleagues in the journal Earth and Planetary Science Letters.

This ‘ultra-primitive’ material is likely to have wafted into the atmosphere after the Earth passed through the trail of the Grigg-Skjellerup comet in 2003.

The interplanetary dust particles (IDPs) used in the study were collected by NASA aircraft in April 2003, after the Earth passed through the dust trail of the comet.

The research team, which included several Carnegie Institution of Washington scientists, analysed a sub-sample of the dust to determine the chemical, isotopic and microstructural composition of its grains.

The results are reported online in Earth and Planetary Science Letters.

“We found an extraordinary wealth of primitive chemical ‘fingerprints’, including abundant pre-solar grains. This is true stardust that has formed around other earlier stars, some during supernova explosions, associated with extremely pristine organic matter that must pre-date the formation of our planets,” said Dr Busemann.

The distinctiveness of the particles, plus the timing of their collection after the Earth’s passing through the comet trail, point to their source being the Grigg-Skjellerup comet.

“This is exciting because it allows us to compare on a microscopic scale in the laboratory dust particles from different comets. We can use them as tracers for different processes that occurred in the solar system four-and-a-half billion years ago,” added Dr Busemann. "These tiny grains combine all the most primitive features, found to date only separately in various meteorites, samples from the previous Stardust mission and interplanetary dust particles.

The particular collection scenario allows us speculate that we truly have samples of a known source in our hands.”

The primitive matter, containing unaltered samples of the building blocks of our Solar System, gives significant insights into the turbulent processes leading to its formation and also the fate of comets orbiting since their formation at the outer edges of our planetary system.

Comets are thought to be repositories of primitive, unaltered matter left over from the formation of the solar system. While the planets in the inner solar system, such as Earth or Mars, once experienced harsh conditions and have changed substantially over the past 4.5 billion years, comets are believed to store the original material of the early Solar System, acting as ‘supersized refrigerators’.

The interplanetary dust particles, which are only a few thousands of a millimetre in diameter, were analysed by an international collaboration from the UK, the US and Germany.

Scientists in the Cosmochemistry research group in the School of Earth, Atmospheric and Environmental Sciences have also been involved in analysing small fragments of material from the Wild 2 comet, which was brought back to earth by NASA's Stardust space mission.

The Stardust mission was launched into space in early February 1999 and encountered Comet Wild 2 in 2004, while nearly 242 million miles from earth.

The NASA mission returned particles captured from the comet in 2006 - the first grains of cometary dust ever returned to earth.

credited to physorg.com

Rare fossil forces rethinking of early dinosaur evolution

2009-12-14T10:00:00.000+01:00

A rare primitive theropod, or a bipedal, primarily carnivorous dinosaur, is bringing clarity to the early evolution of the group that includes more recent relatives like T. rex and birds. Tawa hallae, uncovered in New Mexican sediments from the Upper Triassic, has evidence of an air sack system surrounding the neck and braincase found in birds today, making this characteristic a much more primitive trait than previously thought. But even more enlightening is that a comparison of T. hallae with other early theropods finds that there is a curious mix of early North and South American forms at the base of the carnivorous dinosaur tree. The new research, published in Science, redefines the early evolution of this group as waves of migration from the south rather than as separate and endemic fauna. "We would expect that all of the theropod dinosaurs found in the quarry were related to each other," says Sterling Nesbitt, until recently a graduate student at the American Museum of Natural History who is currently at University of Texas at Austin. "But they are not. T. hallae and two other carnivorous dinosaurs from North America each have their closest relatives in South America."

During the Triassic (about 251 to 199 million years ago), while the supercontinent Pangaea was breaking into northern and southern protocontinents, dinosaurs were rare. Primitive dinosaurs did not dominate the terrestrial fauna yet and comprise only about 6% of tetrapod (four-limbed) fossils found at similar age localities. Instead, crocodylian relatives were common. But during this period, dinosaurs diversified into three distinct groups, the ornithischians, sauropods, and theropods.

T. hallae was discovered in 2004 when hikers stumbled across a few bits of bone at Ghost Ranch in New Mexico. An initial excavation by Alex Downs of the Ruth Hall Museum of Paleontology uncovered limbs and vertebrae that he showed to the other authors. They immediately knew that it was something new from North America's Late Triassic, according to Nesbitt. Nesbitt and colleagues began a full-scale excavation in 2006, part of which was captured during the filming of the IMAX Dinosaurs Alive! "Coincidently, the excavation of what became the holotype is in the film," says Nesbitt.

But more than the holotype (a specimen used to describe a species) was found at Ghost Ranch's Hayden Quarry. The team uncovered five to seven partially articulated individuals buried together in a relatively small pocket (about 2.5 meters by 2.5 meters) among a jumble of tens of thousands of other fossils. T. hallae was in very good condition, allowing a fairly complete reconstruction of a new species of carnivorous biped, and dated to about 215 million years old.

"Finding dinosaurs this old and this complete in an area that has been prospected for over a hundred years is surprising," says Mark Norell, Curator and Division Chair of Paleontology at the American Museum of Natural History. "This is near the site of the dinosaur 'graveyard' where early dinosaurs like Coelophysis have been found since 1947. Now we have more bones from what was early in dinosaur evolution."

In their current paper, the team not only describes T. hallae but fits it in the evolutionary tree with other known theropods. Looking at 15 other theropods and about 300 morphological characteristics, the least complicated, more parsimonious phylogenetic tree now places South American fossils Herrerasaurus and Eoraptor at the base. T. hallae and two other North American species, Chindesaurus and Ceolophysis, both have South American theropods as their closest relatives. This means that there were several waves of theropod migration from South America into North America. This movement correlates with the fossils from many other groups of animals, including crocodylomorphs, aetosaurs, and shuvosaurids, that are found on both land masses. However, another group of saurischian dinosaurs, the sauropods, have not been found in the North America during the Triassic.

"Our biogeographic analyses show that dispersal of early dinosaurs was prevalent during the Triassic, with the multiple theropods from the Hayden Quarry, clearly demonstrating this pattern," says Alan Turner, research associate at the Museum and an assistant professor at Stony Brook University. "We propose that early dinosaurs from South American got into North America at least three separate times. We don't know why sauropods were not in North America, but it looks increasing likely that sauropods were getting here but something was preventing them from staying."

T. hallae is also redefining the history of a very important feature found in many dinosaurs and today's birds, pneumatization of bone, or cavities filled with air. These air sacks often extend into the brain case and ear area. Because T. hallae has an indentation in the bone in the anterior tympanic part of the braincase, this species probably had air sacks filled with air near its ears. This means that this feature is much more primitive that previously assumed. T. hallae also shows evidence of pneumatization along the vertebral column, perhaps to lighten the skeleton.

"T. hallae shows us that some traits go further back in the evolutionary tree," says Norell. "The discovery of fossils of such primitive dinosaurs allows us to link the South American and North American theropod faunas for the first time. Now we can evaluate an entirely new set of biogeographic questions."

credited to American Museum of Natural History

Ancient Kiwi butter found in Antarctica

2009-12-14T09:57:00.001+01:00

The restoration team working on an old Antarctic hut have discovered two blocks of well preserved Kiwi butter, believed to be the oldest in the world.

What is believed to be the world's oldest block of butter has been discovered in the Antarctic.

The Kiwi butter was found frozen in the stable area adjacent to Robert Falcon Scott's hut.

"I think the butter was absolutely a treasure find," says Lizzie Meek, Antarctic Heritage Trust.

Until recently much of the hut was surrounded by snow and ice. A restoration team were working on the adjoining stables when they made the discovery, near a pile of empty butter boxes.

"Oh just tremendous! It looked like an old wrinkly bag and you look inside and saw the wonderful Silver Fern logo," says Meek.

The two-block butter is believed to be the oldest in the world.

"What's amazing is how strong that smells. Nearly a 100 years - very very strong, possibly a bit too strong?" Meek says.

The butter will now be carefully restored.

"(It's) very exciting because there's such a strong connection with New Zealand. And a lot of supplies were given to the expedition by NZ companies and New Zealand people. But it's great to find one with that instantly recognisable Silver Fern and in such great condition relatively speaking," says Meek.

The staff are eager to know where it came from. The label says CCCDC, which is understood to stand for the Canterbury Central Co-operative Dairy Company. The company is thought to have formed in the 1890's and was based in Christchurch.

The big question now is where they are going to keep it as it hardly ever gets above minus ten in the Antarctic stables. The plan is to put the block back where they found it. If it does not deteriorate, they will leave it for another 100 years.

"I hope it'll look pretty similar, perhaps a little dustier but pretty much exactly the same," says Meek.

credited to stuff.co.nz

DNA sheds new light on horse evolution

2009-12-11T09:01:00.001+01:00

Ancient DNA retrieved from extinct horse species from around the world has challenged one of the textbook examples of evolution – the fossil record of the horse family Equidae over the past 55 million years. The study, published today in the Proceedings of the National Academy of Sciences, involved an international team of researchers and the Australian Centre for Ancient DNA (ACAD) based at the University of Adelaide.

Only the modern horse, zebras, wild asses and donkey survive today, but many other lineages have become extinct over the last 50,000 years.

ACAD Director Professor Alan Cooper says despite an excellent fossil record of the Equidae, there are still many gaps in our evolutionary knowledge. "Our results change both the basic picture of recent equid evolution, and ideas about the number and nature of extinct species."

The study used bones from caves to identify new horse species in Eurasia and South America, and reveal that the Cape zebra, an extinct giant species from South Africa, were simply large variants of the modern Plains zebra. The Cape zebra weighed up to 400 kilograms and stood up to 150 centimetres at the shoulder blades.

"The Plains zebra group once included the famous extinct quagga, so our results confirm that this group was highly variable in both coat colour and size."

Lead author of the paper, Dr Ludovic Orlando from the University of Lyon, says the group discovered a new species of the distinct, small hippidion horse in South America.

"Previous fossil records suggested this group was part of an ancient lineage from North America but the DNA showed these unusual forms were part of the modern radiation of equid species," Dr Orlando says.

A new species of ass was also detected on the Russian Plains and appears to be related to European fossils dating back more than 1.5 million years. Carbon dates on the bones reveal that this species was alive as recently as 50,000 years ago.

"Overall, the new genetic results suggest that we have under-estimated how much a single species can vary over time and space, and mistakenly assumed more diversity among extinct species of megafauna," Professor Cooper says.

"This has important implications for our understanding of human evolution, where a large number of species are currently recognised from a relatively fragmentary fossil record.

"It also implies that the loss of species diversity that occurred during the megafaunal extinctions at the end of the last Ice Age may not have been as extensive as previously thought.

In contrast, ancient DNA studies have revealed that the loss of genetic diversity in many surviving species appears to have been extremely severe," Professor Cooper says. "This has serious implications for biodiversity and the future impacts of climate change."

credited to University of Adelaide

New meat-eating dinosaur alters evolutionary tree

2009-12-11T08:58:00.002+01:00

Paleontologists, aided by amateur volunteers, have unearthed a previously unknown meat-eating dinosaur from a fossil bone bed in northern New Mexico, settling a debate about early dinosaur evolution, revealing a period of explosive diversification and hinting at how dinosaurs spread across the supercontinent Pangaea. A live embargoed webcast with the scientists will be held in advance of publication for credentialed reporters on Dec. 9. See details below.

The description of the new species, named Tawa after the Hopi word for the Puebloan sun god, appears in the Dec. 10 issue of the journal Science in a paper lead-authored by Sterling Nesbitt, a postdoctoral researcher at The University of Texas at Austin's Jackson School of Geosciences. Nesbitt conducted the research with his colleagues while a graduate student at Columbia University's Lamont-Doherty Earth Observatory and the American Museum of Natural History.

The fossil bones of several individuals were recovered, but the type specimen is a nearly complete skeleton of a juvenile that stood about 28 inches (70 cm) tall at the hips and was about 6 feet (2 meters) long from snout to tail. Its body was about the size of a large dog, but with a much longer tail. It lived about 214 million years ago, plus or minus a million. The specimens are remarkable because they show little sign of being flattened during fossilization.

Tawa is part of a group of dinosaurs known as theropods, which includes T. Rex and Velociraptor. Theropods for the most part ate meat, walked on two legs and had feathers. Though most went extinct by 65 million years ago, some lineages survived to spawn modern birds.

One of Tawa's most important contributions to science has to do with what it says about another dinosaur, Herrerasaurus, the center of a lively debate since its discovery in Argentina in the 1960s. Herrerasaurus had some traits in common with theropods—including large claws, carnivorous teeth and certain pelvic features—but lacked other theropod traits such as pockets in vertebrae for airsacs. Some paleontologists claimed it was so unusual it was outside the evolutionary tree of theropods, or even of dinosaurs. Others placed it among the earliest theropods.

"The question was did those carnivorous traits arise in Herrerasaurus and in theropods independently or were they traits from a recent common ancestor that got passed down," said Nesbitt. "We had so few specimens of early theropods that it was hard to answer that question. But now that we have Tawa, we think we have an answer."

Tawa had a mix of Herrerasaurus-like characteristics (for example, in the pelvis) and features found in firmly established theropod dinosaurs (for example, pockets for airsacs in the backbone). Therefore, the characteristics that Herrerasaurus shares uniquely with theropods such as Tawa confirm the characteristics didn't arise independently and that Herrerasaurus is indeed a theropod.

The firm placement of Herrerasaurus within the theropod lineage points up an interesting fact about dinosaur evolution: once they appeared, they very rapidly diversified into the three main dinosaur lineages that persisted for more than 170 million years. Herrerasaurus was found in a South American rock layer alongside the oldest members of two major lineages—the sauropods and the ornithischians.

"Tawa pulls Herrerasaurus into the theropod lineage, so that means all three lineages are present in South America pretty much as soon as dinosaurs evolved," said Nesbitt. "Without Tawa, you can guess at that, but Tawa helps shore up that argument."

Tawa skeletons were found beside two other theropod dinosaurs from around the same period. Nesbitt noted that each of the three is more closely related to a known dinosaur from South America than they are to each other. This suggests these three species each descended from a separate lineage in South America, rather than all evolving from a local ancestor, and then later dispersed to North America and other parts of the supercontinent Pangaea. It also suggests there were multiple dispersals out of South America.

The first Tawa fossils were discovered in 2004 by volunteers taking a week-long paleontology seminar with experts at the Ruth Hall Museum of Paleontology in Abiquiu, New Mexico. The dig site, known as Hayden Quarry, is in a hillside on Ghost Ranch made famous by the painter Georgia O'Keefe. Alex Downs, an instructor for the course, contacted Nesbitt and a colleague to ask if they'd like to take a look at the fossils. There was a thigh bone, part of a hip and what later turned out to be some unrelated vertebrae.

"When we saw them, our jaws dropped," said Nesbitt. "A lot of these theropods have really hollow bones, so when they get preserved, they get really crunched. But these were in almost perfect condition."

He was also surprised by how much material was preserved at this one site. He and his colleagues began a full-scale excavation in 2006. Every summer since then, they've continued to unearth new material. The fossil bone bed extends for tens of meters along the hillside, promising years of painstaking work and perhaps additional significant discoveries.

credited to University of Texas at Austin

Why Did Half of N. America's Mammals Disappear 40,000 to 10,000 Years Ago?

2009-12-10T11:36:00.003+01:00

Years of scientific debate over the extinction of ancient species in North America have yielded many theories. However, new findings from J. Tyler Faith, GW Ph.D. candidate in the hominid paleobiology doctoral program, and Todd Surovell, associate professor of anthropology at the University of Wyoming, reveal that a mass extinction occurred in a geological instant.

During the late Pleistocene, 40,000 to 10,000 years ago, North America lost over 50 percent of its large mammal species. These species include mammoths, mastodons, giant ground sloths, among many others. In total, 35 different genera (groups of species) disappeared, all of different habitat preferences and feeding habits.

What event or factor could cause such a mass extinction? The many hypotheses that have been developed over the years include: abrupt change in climate, the result of comet impact, human overkill and disease. Some researchers believe that it may be a combination of these factors, one of them, or none.

A particular issue that has also contributed to this debate focuses on the chronology of extinctions. The existing fossil record is incomplete, making it more difficult to tell whether or not the extinctions occurred in a gradual process, or took place as a synchronous event. In addition, it was previously unclear whether species are missing from the terminal Pleistocene because they had already gone extinct or because they simply have not been found yet.

However, new findings from Faith indicate that the extinction is best characterized as a sudden event that took place between 13.8 and 11.4 thousand years ago. Faith's findings support the idea that this mass extinction was due to human overkill, comet impact or other rapid events rather than a slow attrition.

"The massive extinction coincides precisely with human arrival on the continent, abrupt climate change, and a possible extraterrestrial impact event" said Faith. "It remains possible that any one of these or all, contributed to the sudden extinctions. We now have a better understanding of when the extinctions took place and the next step is to figure out why."

George Washington University (2009, November 27). Mass extinction: Why did half of N. America's large mammals disappear 40,000 to 10,000 years ago?. ScienceDaily. Retrieved December 10, 2009, from http://www.sciencedaily.com /releases/2009/11/091127140706.htm