Thursday, October 1, 2009

Ancient Rainforests Resilient To Climate Change.


ScienceDaily (Oct. 1, 2009) — Climate change wreaked havoc on the Earth’s first rainforests but they quickly bounced back, scientists reveal. The findings of the research team, led by Dr Howard Falcon-Lang from Royal Holloway, University of London, are based on spectacular discoveries of 300-million-year-old rainforests in coal mines in Illinois, USA.
Preserved over vast areas, these fossilized rainforests in Illinois are the largest of their kind in the world. The rocks at this site - in which the rainforests occur - contain evidence for climate fluctuations. During cold ‘ice ages’, fossils show that the tropics dried out and rainforests were pushed to the brink of extinction. However, rainforests managed to recover and return to their former glory.
Dr Falcon-Lang, from the Department of Earth Sciences, worked with colleagues at the Smithsonian Institution and Illinois Geological Survey. In their paper published in the journal Geology, they show that rainforest species all but vanished at the height of the ice ages. Yet they also reveal that the coal beds that formed shortly after, as the climate warmed, contain abundant rainforest species.
Falcon-Lang said, ‘These discoveries radically change our understanding of the Earth’s first rainforests. We used to think these were stable ecosystems, unchanged for tens of millions of years. Now we know they were incredibly dynamic, constantly buffeted by climate change’.
The research may also shed light on how climate change will affect the Amazon rainforest in the future. Dr Falcon-Lang commented, ‘If we can understand how climate shaped rainforests in the distant past, we can infer how they will respond in the future. We’ve shown that within certain limits, rainforests are resilient to climate change; however, extreme climate change may push rainforests beyond a point of no return’.
The work is part of a five-year project funded by the UK’s Natural Environment Research Council and aims to study how climate change affected the Earth’s first rainforests. These ancient rainforests date from the Carboniferous period, 300 million years ago, when most of the world's coal resources were formed.
Adapted from materials provided by
University of Royal Holloway London, via AlphaGalileo.

Archaeologists Discover Amphitheatre In Excavation Of Portus, Ancient Port Of Rome.

ScienceDaily (Oct. 1, 2009) — University of Southampton archaeologists leading a major excavation of Portus, the ancient port of Rome, have uncovered the remains of an amphitheatre-shaped-building, solving a mystery which has puzzled experts for over 140 years.
The excavation team, working in collaboration with the British School at Rome, is conducting the first ever large-scale dig at Portus on the banks of a hexagonal shaped man-made lake which formed the 2nd century harbour, near the Italian capital.
"When the site was visited by archaeologist Rodolfo Lanciani in the 1860s he marked on his plans the remains of a theatre, but subsequently no trace of the building could be found," says Portus Project Director and leading expert in Roman Archaeology at the University of Southampton, Professor Simon Keay.
"Our team has rediscovered this 'theatre' and proved it was in fact a building more akin to an amphitheatre. Lanciani had only found half of the structure, leading him to misinterpret its shape and function."
Funded by the Arts and Humanities Research Council, experts from Southampton have been working with colleagues from the BSR, The Italian Archaeological Superintendency for Ostia and the University of Cambridge, to carry out extensive excavation at Portus. They have uncovered a large Roman warehouse, the 'amphitheatre' and what the team have identified as an Imperial palace. This is likely to have played host to renowned emperors such as Hadrian.
Portus was Rome's gateway to the Mediterranean for most of the Imperial period and played a key role in funnelling food, slaves, wild animals, marble and all manner of luxury goods from across the Mediterranean and beyond to the citizens of Rome. It was vital to the survival of the Empire and the only real 'transport hub' serving the city.
"The 'amphitheatre' we have discovered was similar in ground area to the Pantheon in Rome, but it is unclear exactly what it was used for," continues Professor Keay.
"Gladiatorial combat may have taken place there - wild beast baiting, the staging of mock sea battles, or it may have been a form of Roman 'folly', shaped like an amphitheatre, but used as a monumental garden. It is unusual to find this type of building so close to a harbour."
Having solved one riddle, archaeologists have now uncovered another; the white marble head of a statue unearthed at the site of once-luxurious rooms close to the 'amphitheatre'. It is thought the head dates back to the 2nd or early 3rd century, however it is less clear who it depicts.
"The elderly bearded male wearing a flat skull-cap could suggest it is Ulysses, however it is equally possible it is a representation of one of the Greek sailors who accompanied him on his travels. For the moment his identity remains a mystery," concludes Professor Keay.
Part of the 'Portus Project' involves the work of the University of Southampton's Archaeological Computing Research Group. They are producing computer generated images which bring the port to life and provide archaeologists with a valuable 'tool' with which to explore the site. The University of Southampton and the BSR are jointly using ground-penetrating radar and other techniques to map buried buildings and other structures. The Portus Project has also been undertaking a geophysical survey of the Isola Sacra, an island to the south of Portus, and has found a major new canal and traces of Rome's marble yards.
Research has been underway at Portus for several years and Professor Keay hopes to continue working there. "This is one of the most important archaeological sites in the world," he says.
"Certainly it should be rated alongside such wonders as Stonehenge and Angkor Wat in Cambodia. So much of this Imperial port has been preserved and there is much more to learn about its role in supplying Rome and in the broader economic development of the Roman Mediterranean."
Adapted from materials provided by
University of Southampton, via AlphaGalileo.

Before 'Lucy,' There Was 'Ardi': First Major Analysis Of Early Hominid Published In Science.


ScienceDaily (Oct. 1, 2009) — In a special issue of Science, an international team of scientists has for the first time thoroughly described Ardipithecus ramidus, a hominid species that lived 4.4 million years ago in what is now Ethiopia.
This research, in the form of 11 detailed papers and more general summaries, will appear in the journal's 2 October 2009 issue. Science is published by AAAS, the nonprofit science society.
This package of research offers the first comprehensive, peer-reviewed description of the Ardipithecus fossils, which include a partial skeleton of a female, nicknamed "Ardi."
The last common ancestor shared by humans and chimpanzees is thought to have lived six or more million years ago. Though Ardipithecus is not itself this last common ancestor, it likely shared many of this ancestor's characteristics. For comparison, Ardipithecus is more than a million years older than the "Lucy" female partial skeleton of Australopithecus afarensis. Until the discovery of the new Ardipithecus remains, the fossil record contained scant evidence of other hominids older than Australopithecus.
Through an analysis of the skull, teeth, pelvis, hands, feet and other bones, the researchers have determined that Ardipithecus had a mix of "primitive" traits, shared with its predecessors, the primates of the Miocene epoch, and "derived" traits, which it shares exclusively with later hominids.
Because of its antiquity, Ardipithecus takes us closer to the still-elusive last common ancestor. However, many of its traits do not appear in modern-day African apes. One surprising conclusion, therefore, is that it is likely that the African apes have evolved extensively since we shared that last common ancestor, which thus makes living chimpanzees and gorillas poor models for the last common ancestor and for understanding our own evolution since that time.
"In Ardipithecus we have an unspecialized form that hasn't evolved very far in the direction of Australopithecus. So when you go from head to toe, you're seeing a mosaic creature, that is neither chimpanzee, nor is it human. It is Ardipithecus," said Tim White of the University of California Berkeley, who is one of the lead authors of the research.
"With such a complete skeleton, and with so many other individuals of the same species at the same time horizon, we can really understand the biology of this hominid," said Gen Suwa of the University of Tokyo, Project paleoanthropologist and also a lead Science author.
"These articles contain an enormous amount of data collected and analyzed through a major international research effort. They throw open a window into a period of human evolution we have known little about, when early hominids were establishing themselves in Africa, soon after diverging from the last ancestor they shared with the African apes," said Brooks Hanson, deputy editor, physical sciences, at Science.
"Science is delighted to be publishing this wealth of new information, which gives us important new insights into the roots of hominid evolution and into what makes humans unique among primates," said Hanson.
The special collection of Science articles begins with an overview paper that summarizes the main findings of this research effort. In this article, White and his coauthors introduce their discovery of over 110 Ardipithecus specimens including a partial skeleton with much of the skull, hands, feet, limbs and pelvis. This individual, "Ardi," was a female who weighed about 50 kilograms and stood about 120 centimeters tall.
Until now, researchers have generally assumed that chimpanzees, gorillas and other modern African apes have retained many of the traits of the last ancestor they shared with humans – in other words, this presumed ancestor was thought to be much more chimpanzee-like than human-like. For example, it would have been adapted for swinging and hanging from tree branches, and perhaps walked on its knuckles while on the ground.
Ardipithecus challenges these assumptions, however. These hominids appear to have lived in a woodland environment, where they climbed on all fours along tree branches – as some of the Miocene primates did -- and walked, upright, on two legs, while on the ground. They do not appear to have been knuckle-walkers, or to have spent much time swinging and hanging from tree-branches, especially as chimps do. Overall, the findings suggest that hominids and African apes have each followed different evolutionary pathways, and we can no longer consider chimps as "proxies" for our last common ancestor.
"Darwin was very wise on this matter," said White.
"Darwin said we have to be really careful. The only way we're really going to know what this last common ancestor looked like is to go and find it. Well, at 4.4 million years ago we found something pretty close to it. And, just like Darwin appreciated, evolution of the ape lineages and the human lineage has been going on independently since the time those lines split, since that last common ancestor we shared," White said.
This special issue of Science includes an overview article, three articles that describe the environment Ardipithecus inhabited, five that analyze specific parts of Ardipithecus' anatomy, and two that discuss what this new body of scientific information may imply for human evolution.
Altogether, forty-seven different authors from around the world contributed to the total study of Ardipithecus and its environment. The primary authors are Tim White of the University of California, Berkeley, Berhane Asfaw of Rift Valley Research Service in Addis Ababa, Giday WoldeGabriel of Los Alamos National Laboratory, Gen Suwa of the University of Tokyo, and C. Owen Lovejoy of Kent State University.
"These are the results of a mission to our deep African past," said WoldeGabriel, who is also Project co-Director and geologist.
This research was funded by the National Science Foundation, the Institute of Geophysics and Planetary Physics of the University of California at Los Alamos National Laboratory (LANL), the Japan Society for the Promotion of Science, and others.
Adapted from materials provided by
American Association for the Advancement of Science, via EurekAlert!, a service of AAAS.

Was Mighty T. Rex 'Sue' Felled By A Lowly Parasite?

ScienceDaily (Sep. 30, 2009) — When pondering the demise of a famous dinosaur such as 'Sue,' the mighty Tyrannosaurus rex whose fossilized remains are a star attraction of the Field Museum in Chicago, it is hard to avoid the image of clashing Cretaceous titans engaged in bloody, mortal combat.
It is an image commonly promoted by museums and dinosaur aficionados. Sue's remains, in fact, exhibit holes in her jaw that some believed were battle scars, the result of conflict with another dinosaur, possibly another T. rex.
But a new study, published in the online journal PLoS ONE, provides evidence that Sue, perhaps the most famous dinosaur in the world, was felled in more mundane fashion by a lowly parasite that still afflicts modern birds. The study, conducted by an international team of researchers led by Ewan D.S. Wolff of the University of Wisconsin-Madison and Steven W. Salisbury of the University of Queensland, Australia, pins the demise of Sue and other tyrannosaurs with similar scars on an avian parasitic infection called trichomonosis, caused by a single-celled parasite that causes similar pathologies on the mandibles of modern birds, raptors in particular.
It is possible the infection in her throat and mouth may have been so acute that the 42-foot-long, 7-ton dinosaur starved to death, says Wolff, a vertebrate paleontologist and a third-year student at the UW-Madison School of Veterinary Medicine. Co-authors of the study include famed paleontologist John R. Horner of the Museum of the Rockies, which funded the study, and David J. Varricchio of Montana State University.
The focus of the new study was a survey of lesions on the jaws of Sue and nine other tyrannosaur specimens. The lesions had previously been attributed to bite wounds or, possibly, a bacterial infection.
"What drew my attention to trichomonosis as a potential candidate for these mysterious lesions on the jaws of tyrannosaurs is the manifestation of the effects of the disease in [bird] raptors," explains Wolff. "When we started looking at trichomonosis in greater depth, there was a story that matched some lines of evidence for transmission of the disease in tyrannosaurs."
In birds, trichomonosis is caused by a protozoan parasite called Trichomonas gallinae. It can be transmitted from birds such as pigeons, which commonly carry the parasite but often suffer few ill effects, to raptors such as falcons and hawks, where it causes serious lesions in the mandibles. The pattern of lesions, says Wolff, closely matches the holes in the jaws of tyrannosaurs and occurs in the same anatomical location.
The scars of combat among tyrannosaurs and other dinosaurs, Wolff notes, are not uncommon, but differ notably from the lesions that are the focus of the current study. The holes caused by trichomonosis tend to be neat and have relatively smooth edges, while bite marks are often messy, and they scar and puncture bone in ways that are not readily comparable.
Tyrannosaurs, notes Wolff, are known to have been gregarious, intermingling, fighting amongst themselves, and sometimes eating one another. Transmission of the parasite may have been through salivary contact or cannibalism, he says, noting that there is no known evidence of trichomonosis in other dinosaurs.
"This leads us to suspect that tyrannosaurs might have been the source of the disease and its transmission in its environment," Wolff says.
For the disease to manifest itself in the jaws of Sue and other tyrannosaurs, it would have had to be at an advanced stage as the parasite typically sets up housekeeping as a film in the back of the throat.
"The lesions we observe on Sue suggest a very advanced stage of the disease and may even have been the cause of her demise," says Wolff. "It is a distinct possibility as it would have made feeding incredibly difficult. You have to have a viable pharynx. Without that, you won't make it for very long, no matter how powerful you are."
Journal reference:
Ewan D. S. Wolff, Steven W. Salisbury, John R. Horner, David J. Varricchio. Common Avian Infection Plagued the Tyrant Dinosaurs. PLoS ONE, 2009; 4(9): e7288 DOI:
Adapted from materials provided by University of Wisconsin-Madison.

Thursday, July 23, 2009

Human Spear Likely Cause Of Death Of Neandertal

ScienceDaily (July 22, 2009) — The wound that ultimately killed a Neandertal man between 50,000 and 75,000 years was most likely caused by a thrown spear, the kind modern humans used but Neandertals did not, according to Duke University-led research.
"What we've got is a rib injury, with any number of scenarios that could explain it," said Steven Churchill, an associate professor of evolutionary anthropology at Duke. "We're not suggesting there was a blitzkrieg, with modern humans marching across the land and executing the Neandertals. I want to say that loud and clear."
But Churchill's analysis indicates the wound was from a thrown spear, and it appears that modern humans had a thrown-weapons technology and Neandertals didn't. "We think the best explanation for this injury is a projectile weapon, and given who had those and who didn't that implies at least one act of inter-species aggression."
Churchill is the first author of a new report now posted online in the Journal of Human Evolution on the long-ago incident in what is now Iraq. He and four other investigators used a specially calibrated crossbow, copies of ancient stone points and numerous animal carcasses to make their deductions.
Neandertals, stoutly-built and human-like, lived at the same time and in the same areas as some modern humans before going extinct. Anthropologists have been puzzling over Neandertal's fate for many years, proposing that perhaps they inter-bred with modern humans, failed to compete for food or resources, or were possibly hunted to extinction by the humans.
While narrowing the range of possible causes for the Iraqi Neandertal's wound, and raising the possibility of an encounter between humans and a now-extinct close cousin, the research does not definitively conclude who did it, or why.
The victim was one of nine Neandertals discovered between 1953 and 1960 in a cave in northeastern Iraq's Zagros Mountains. Now called "Shanidar 3," he was a 40- to 50-year-old male with signs of arthritis and a sharp, deep slice in his left ninth rib.
The wounded Neandertal's rib had apparently started healing before he died. Comparing the wound to medical records from the American Civil War, a time before modern antibiotics, suggested to the researchers that he died within weeks of the injury, perhaps due to associated lung damage from a stabbing or piercing wound.
"People have been speculating about that rib injury for going on 50 years now," Churchill said. "Some said it was interpersonal violence. Others said it could have been an accident. Did it involve only Neandertals? Now we, for the first time, have brought some experimental evidence to bear on these questions."
While scientists have been unable to precisely date the remains, Shanidar 3 could have lived and died as recently as 50,000 years ago. If so, he could have encountered modern humans who were just returning to the area then after a 30,000-year hiatus.
Archaeological evidence also suggests that by 50,000 years ago humans, but not their Neandertal cousins, had developed projectile hunting weapons, Churchill said. They used spear throwers, detachable handles that connected with darts and spears to effectively lengthen a hurler's arm and give the missiles a power boost.
As human weapons technology advanced, Neandertals continued using long thrusting spears in hunting, which they probably tried -- for personal safety -- to keep between themselves and their prey instead of hurling them, Churchill added.
Both Neandertals and humans were also armed with stone knives. And both species had developed techniques for making sharp stone points.
Looking back at this Paleolithic cold case, the study's authors evaluated all the possible causes of the rib wound with the aid of contemporary tools.
The injury is "consistent with a number of scenarios, including wounding from a long-range projectile (dart) weapon, knife stab, self-inflicted accidental injury and accidental stabbing by a hunting partner," the report said.
Drawing from studies aimed at improving police and prison guard protection, the researchers concluded that the downward sweep of a knife could have the correct trajectory to produce Shanidar 3's rib injury. "Knife attacks generally involve a relatively higher kinetic energy," the report said. However, "whatever created that puncture was carrying fairly low kinetic energy at a low momentum," said Churchill. "That's consistent with a spear-thrower delivered spear."
The investigators rigged up a special crossbow to fire stone-age projectiles, using calibration marks on the crossbow to tell them how much force they were delivering with each launch.
Those tests revealed the delivered energy needed to create similar wounds in the ribs of pig carcasses, which the researchers used as an approximation of a Neandertal's body.
The researchers also used measurements from a 2003 study to estimate the impact of using a thrusted rather than thrown spear, the kind of jabbing that Neandertals are thought to have employed. That produced higher kinetic energies and caused more massive rib damage than Shanidar 3 sustained.
Another clue was the angle of the wound. Whatever nicked his rib entered the Neandertal's body at about 45 degrees downward angle. That's consistent with the "ballistic trajectory" of a thrown weapon, assuming that Shanidar 3 -- who was about 5 feet, 6 inches tall -- was standing, Churchill said.
Shanidar 3 is one of two known Neandertal skeletons bearing evidence of a possible stone tool injury. The other remains, found in France, had an almost-healed head wound. That individual is known to have lived "at a time of overlap with modern humans we call the Cro-Magnon," Churchill said.
The study was funded by the National Science Foundation, the L.S.B. Leakey Foundation and the University of New Mexico. Other co-authors of the Journal of Human Evolution report include Robert Franciscus, an associate professor of anthropology at the University of Iowa; and three Duke alumni who assisted Churchill as undergraduates -- Hilary McKean-Peraza, Julie Daniel and Brittany Warren.
Adapted from materials provided by Duke University.

Wednesday, July 22, 2009

Ancient Humans Left Evidence From The Party That Ended 4,000 Years Ago

ScienceDaily (July 22, 2009) — The party was over more than 4,000 years ago, but the remnants still remain in the gourds and squashes that served as dishware. For the first time, University of Missouri researchers have studied the residues from gourds and squash artifacts that date back to 2200 B.C. and recovered starch grains from manioc, potato, chili pepper, arrowroot and algarrobo. The starches provide clues about the foods consumed at feasts and document the earliest evidence of the consumption of algarrobo and arrowroot in Peru.
"Archaeological starch grain research allows us to gain a better understanding of how ancient humans used plants, the types of food they ate, and how that food was prepared," said Neil Duncan, doctoral student of anthropology in the MU College of Arts and Science and lead author of the study that was published in the Proceedings of the National Academy of Science (PNAS). "This is the first study to analyze residue from bottle gourd or squash artifacts. Squash and bottle gourds had a variety of uses 4,000 years ago, including being used as dishes, net floats and symbolic containers. Residue analysis can help determine the specific use."
In the study, researchers recovered starch grains from squash and gourd artifacts by a method that currently is used to recover microfossils from stone tools and ceramics. First, the artifact was placed in a special water bath to loosen and remove adhering residue. Then the artifact's interior surface was lightly brushed to remove any remaining residue. The residues were collected, and starch grains were isolated from each of these sediments.
"The starch residues of edible plants found on the artifacts and the special archaeological context from which these artifacts were recovered suggest that the artifacts were used in a ritual setting for the serving and production of food," Duncan said. "The method used in this study could be used in other areas and time periods in which gourds and squash rinds are preserved."
Scientists believe the Buena Vista site, where the starch grains were recovered, served as a small ceremonial center in the central Chillon Valley. The social and ritual use of food is not well understood during this time period in Peru, but this research will enhance the potential for understanding, Duncan said.
The study, "Gourd and squash artifacts yield starch grains of feasting foods from preceramic Peru," is coauthored by Duncan; Deborah Pearsall, professor of anthropology; and Robert Benfer, emeritus professor of anthropology.
Journal reference:
Neil Duncan et al. Gourd and squash artifacts yield starch grains of feasting foods from preceramic Peru. Proceedings of the National Academy of Science, July 21, 2009
Adapted from materials provided by University of Missouri-Columbia.

Friday, July 17, 2009

Could Cannon Balls From The Early 19th Century Sink Warships?

ScienceDaily (July 16, 2009) — A joint experiment by researchers at the University of Haifa and Rafael Advanced Defense Systems Ltd. succeeded in solving the riddle: Could cannon balls from the early 19th century sink warships?
At first glance, the hull of the warship that sank off the coast of Acre seemed strong; but a unique experiment indicated that the thick timbers could not withstand the cannon balls.
A joint experiment carried out by researchers from the Leon Recanati Institute for Maritime Studies at the University of Haifa and staff of Rafael Advanced Defense Systems Ltd. has solved the riddle that has been puzzling researchers ever since they first observed the thick wooden sides of the sunken ship opposite the shore of Acre: could cannon fire have penetrated the hull?
The ship was discovered in 1966, but only since University of Haifa researchers began examining it about three years ago have its mysteries been exposed. The initial matters of interest related to the ship's origins, date and the reason why it sank. A map drawn up by a British officer in 1799, during Napoleon's siege of Acre, led the researchers to assume that this was a blockship sunk by the British to bar French vessels from entering the port.
Another puzzle that has occupied the researchers, however, relates to the thickness of the ship's hull. According to Dr. Yaacov Kahanov, who heads the research team, it was evident at first glance that the hull, which was constructed of oak, was unusually thick, leading the team to question the possibility of cannon-ball penetration. Experimental firings of cannons at replicas of wooden warships have been carried out in other countries, but due to the cost and complexity of such experiments, they have been few and far between. In general, they were only firing demonstrations, and scientific data has not always been obtained. So it was still hard to tell for sure whether the cannon balls found in the wreck would have been capable of sinking this particular ship.
The University of Haifa marine researchers received assistance from a team of Rafael engineers, who developed a unique model that enabled firing experiments to be carried out on a reduced scale, thereby reducing costs, and enabling controlled, measured and documented experimentation. The present experiment was carried out at a scale of 1:2, for which five models of the ship's hull, based on the archaeological findings, were constructed at the University. In parallel, Rafael adapted an experimental gun to fire steel balls, modeling the cannon balls. Meticulous measurements were taken to ensure setting the range of muzzle velocities of the period; 100-500 meters per second.
The experiments showed in the most dramatic way that, despite the hull's strength, it could not withstand the impact of the cannon fire, which penetrated it even at the lowest velocities. It also became evident that the lower the velocity, the more energy was absorbed in causing damage to the hull, and the more the wood splintered, which would have caused more harm to the ship's personnel. The results of this experiment, according to the researchers, are of much significance to the study of the vessel and to the study of naval battles in this period.
Adapted from materials provided by University of Haifa, via EurekAlert!, a service of AAAS.

Wednesday, July 15, 2009

Crocodile Skull Unearthed At Arlington Archosaur Site In Texas

ScienceDaily (July 15, 2009) — Paleontologists have made the most important discovery to date at the Arlington Archosaur Site, a prolific fossil site in North Arlington, Texas. The disassembled skull of a crocodile with two and a half inch long teeth that lived nearly 100 million years ago has been unearthed.
"We have over 50 bones exposed," said The University of Texas at Arlington dinosaurs lecturer Derek Main, who heads the project. "They are truly impressive. The teeth measure 6.5 centimeters, larger than my thumb."
To date, more dinosaur fossils have been recovered from the Arlington Archosaur Site, where excavation began little more than a year ago, than from any other site in the Dallas-Fort Worth area. The site lies within Cretaceous rocks, formed 95 million years ago when Arlington was the beachhead for a giant sea that divided the continent.
The site has yielded fossils from various species of animals, including dinosaurs. A skeleton of a large herbivorous "duck billed" dinosaur was excavated from the northern hillside at the site. Crocodile fossils are among the most commonly found.
Main said the site is unique because it is a major dinosaur excavation in the middle of a large metropolitan setting and it preserves many fossils from different animals. he site also has fossils from turtles, lungfish, fish and sharks. The excavation of the Arlington Archosaur Site began in the spring of 2008 when the Huffines Group obtained the property and granted land access to UT Arlington.
Adapted from materials provided by University of Texas At Arlington.

Last Supper Of The Hominids Establishes Times They Lived At Sites

ScienceDaily (July 15, 2009) — In the French cave of Arago, an international team of scientists has analyzed the dental wear of the fossils of herbivorous animals hunted by Homo heidelbergensis. It is the first time that an analytical method has allowed the establishment of the length of human occupations at archaeological sites. The key is the last food that these hominids consumed.
For many years, the mobility of the groups of hominids and how long they spent in caves or outdoors has been a subject of discussion among scientists. Now, an international team headed by researchers from the Catalan Institute of Human Paleoecology and Social Evolution (IPHES) in Tarragona has based its studies on the dental fossils of animals hunted by hominids in order to determine the vegetation in the environment and the way of life of Homo heidelbergensis.
Florent Rivals is the main author and a researcher from the Catalan Institute for Research and Advanced Studies (ICREA), attached to the IPHES in Tarragona. "For the first time, a method has been put forward which allows us to establish the relative length of the human occupations at archaeological sites as, up until now, it was difficult to ascertain the difference between, for example, a single long-term occupation and a succession of shorter seasonal occupations in the same place", he explained to SINC.
In the study, recently published in the Journal of Human Evolution, the researchers analyze the dental wear of the ungulates (herbivorous mammals) caused by microscopic particles of opaline silica in plants. These marks appear when eating takes place and erase the previous ones. This is why they are so useful.
Thanks to the "last supper phenomenon", the scientists have been able to analyze the last food consumed by animals such as the Eurasian wild horse (Equus ferus), the mouflon (Ovis ammon antiqua) and the reindeer (Rangifer tarandus). "This method allows us to confirm the seasonal nature of the occupation", Rivals added. According to the team, the microwear of the teeth is sensitive to seasonal changes in the diet.
The application has allowed the researchers to estimate the length of the occupation of the site from the Lower Paleolithic Age in the cave of Arago (France) by the number of marks on the fossils and, therefore, the variation in the diet of several species of herbivores, as "each season presented food resources which were limited and different in the environment", the paleontologist clarified.
High and low periods of occupation
After confirming the hypothesis in present-day animals whose age and date of death was known to the scientists, the researchers demonstrated that, if a group of animals is seen during a specific season (a short-term occupation), the signs of dental wear undergo little variation. But if the occupation lasts several seasons, the dental marks are more diverse.
"If the animals are hunted during long periods of occupation, more variable dental wear would be expected", Rivals declared. In the case of the French cave of Arago, the study of the dental wear confirms that it was occupied in different ways. "With this method, we were able to prove that at the site, which belonged to Homo heidelbergensis, there is evidence of differing mobility, as there were highly mobile groups and others with little mobility", the scientist confirmed.
The Spanish and German researchers have combined this application with multidisciplinary studies of archaeological sites in order to apply it to other settlements of the Mid-Paleolithic Age such as Payre (France), Taubach (Germany) and Abric Romani (Spain).
Journal reference:
Rivals et al. A new application of dental wear analyses: estimation of duration of hominid occupations in archaeological localities. Journal of Human Evolution, 2009; 56 (4): 329 DOI: 10.1016/j.jhevol.2008.11.005
Adapted from materials provided by FECYT - Spanish Foundation for Science and Technology.

Tuesday, July 14, 2009

Sharks: Missing Piece Of Fossil Puzzle Found

ScienceDaily (July 14, 2009) — The mode of reproduction seen in modern sharks is nearly 400 million years old. That is the conclusion drawn by Professor Per Erik Ahlberg, Uppsala University, from his discovery of a so-called "clasper" in a primitive fossil fish earlier this year. The research results are published in Nature.
In February this year, a paper published in Nature by a team of Australian and British researchers showed that placoderms, a group of ancient fishes that died out more than 350 million years ago, gave birth to live young. Beautifully preserved fossil embryos in the body cavity of the placoderm Incisoscutum showed that these fishes, close to the common origin of all jawed vertebrates, had a mode of reproduction similar to modern sharks.
Live birth requires internal fertilization. Sharks achieve this by using a "clasper", an extension of the pelvic fin that functions like a penis. The authors looked for a clasper in their placoderm fossils but couldn't find one, so they were forced to argue that it had been made of soft cartilage and had not been preserved.
Shortly afterwards, Per Erik Ahlberg from Uppsala University visited one of the Australian researchers and spotted a perfectly preserved bony clasper in one of their Incisoscutum fossils.
"It was lying in plain view but had been misinterpreted as part of the pelvis and overlooked," he says.
Together with the original authors he is publishing a short paper in the journal Nature that presents this missing piece of the puzzle and completes the picture of placoderm reproduction from mating to birth.
"It provides a pedigree of nearly 400 million years for the "advanced" and seemingly specialized reproductive biology of modern sharks," says Per Ahlberg.
Journal reference:
Per Ahlberg, Kate Trinajstic, Zerina Johanson & John Long. Pelvic claspers confirm chondrichthyan-like internal fertilization in arthrodires. Nature, 2009; DOI: 10.1038/nature08176
Adapted from materials provided by Uppsala University.

Saturday, July 11, 2009

Down Under Dinosaur Burrow Discovery Provides Climate Change Clues

ScienceDaily (July 11, 2009) — On the heels of his discovery in Montana of the first trace fossil of a dinosaur burrow, Emory University paleontologist Anthony Martin has found evidence of more dinosaur burrows – this time on the other side of the world, in Victoria, Australia. The find, to be published this month in Cretaceous Research, suggests that burrowing behaviors were shared by dinosaurs of different species, in different hemispheres, and spanned millions of years during the Cretaceous Period, when some dinosaurs lived in polar environments.
"This research helps us to better understand long-term geologic change, and how organisms may have adapted as the Earth has undergone periods of global cooling and warming," says Martin, a senior lecturer in environmental studies at Emory. Martin is also an honorary research associate at Monash University in Melbourne.
In 2006, in collaboration with colleagues from Montana State University and Japan, Martin identified the 95-million-year-old skeletal remains of a small adult dinosaur and two juveniles in a fossilized burrow in southwestern Montana. They later named the dinosaur species Oryctodromeus cubicularis, meaning "digging runner of the lair."
The researchers hypothesized that, besides caring for young in their dens, burrowing may have allowed some dinosaurs to survive extreme environments – throwing a wrench in some extinction theories.
A year after the Montana find, Martin traveled to the Victoria coast, which marks the seam where Australia once snuggled against Antarctica. Lower Cretaceous strata of Victoria have yielded the best-documented assemblage of polar dinosaur bones in the world.
During a hike to a remote site known as Knowledge Creek, west of Melbourne, Martin rounded the corner of an outcropping and was astounded to see, right at eye level, the trace fossil of what appeared to be a burrow almost identical to the one he had identified in Montana. "I stared at it for a long time," recalls Martin. "In paleontology, the saying, 'where luck meets preparation' really holds true."
The probable burrow etched into the Early Cretaceous outcrop is about six-feet long and one-foot in diameter. It gently descends in a semi-spiral, ending in an enlarged chamber. Martin later found two similar trace fossils in the same area.
Last period of global warming
The Victoria fossils are about 110 million years old, around the time that Australia split with Antarctica, and dinosaurs roamed in prolonged polar darkness along forested southern Australia river plains. It was one of the last times the Earth experienced global warming, with an average temperature of 68 degrees Fahrenheit – about 10 degrees higher than today.
During the polar winter, though, the temperature could plunge below freezing. Previously, researchers theorized that the small dinosaurs in the region survived harsh weather by sheltering beneath large tree roots or in hollows. Martin's find, however, indicates that they may have dug into the soft banks of rivers flowing out of the rift valley.
The age, size and shape of the likely burrows led Martin to hypothesize that they were made by small ornithopod dinosaurs – herbivores that were prevalent in the region. These ornithopods stood upright on their hind legs and were about the size of a large, modern-day iguana.
"It's fascinating to find evidence connecting a type of behavior between dinosaurs that are probably unrelated, and lived in different hemispheres during different times," Martin says. "It fills in another gap in our understanding of the evolution of dinosaurs, and ways they may have survived extreme environments."
An eye for subtle clues
A specialist in trace fossils – including tracks, scat and burrows – Martin is known for detecting subtle paleontology clues. He also identified the first tracks of a large, carnivorous dinosaur in Victoria, and the first fossil crayfish burrows from the same area.
Martin teaches a seminar at Emory on modern-day animal tracking, a skill that he says aids him in finding signs of prehistoric life. "It's important to do as much field work as possible, because it gives your mind a better library of search images," he says.
Adapted from materials provided by Emory University.

Tuesday, July 7, 2009

Preserved organic molecules in the skin of a dinosaur that died around 66-million years ago, identified.

ScienceDaily (July 8, 2009) — Scientists from The University of Manchester have identified preserved organic molecules in the skin of a dinosaur that died around 66-million years ago.
The well-preserved fossil of the plant-eating hadrosaur – known as ‘Dakota’ – has been analysed by researchers writing in the journal Proceedings of the Royal Society B.
The team report how the fossil's soft tissues were spared from decay by fine sediments that formed a mineral cast.
A wide range of tests have shown that the fossil still holds cell-like structures, although the constituent proteins have decayed.
Advanced imaging and chemical techniques have revealed that the mummified duckbilled dinosaur had two layers of skin – just like the skin of modern birds and reptiles, which scientists believe are closely related to duckbilled dinosaurs.
They believe the hippo-sized Dakota fell into a watery grave, with little oxygen present to speed along the decay process. Meanwhile, very fine sediments reacted with the soft tissues of the animal, forming a kind of cement.
As a result, the 66 million-year-old fossil still retains some of the organic matter of the original dinosaur, mixed in with the minerals.
"You're looking at cell-like structures; you slice through this and you're looking at the cell structure of dinosaur skin,” said Dr Phil Manning, Senior Lecturer in Palaeontology & Research Fellow School of Earth, Atmospheric & Environmental Sciences (SEAES). “That is absolutely gobsmacking."
The Manchester research team comprised Dr Phil Manning (SEAES and Manchester Museum), Peter Morris (SEAES and the Williamson Research Centre for Molecular Environmental Science), Adam McMahon and Emrys Jones (Wolfson Molecular Imaging Centre), Andy Gize and Joe Macquaker (SEAES), Prof Simon Gaskell and Onrapak Reamtong (Manchester Interdisciplinary Biocentre), Dr Bill Sellers (Faculty of Life Science), Bart van Dongen (SEAES and Williamson Research Centre for Molecular Environmental Science), Mike Buckley and Dr Roy Wogelius (SEAES and Williamson Research Centre for Molecular Environmental Science)
Scientists at The University of Liverpool, Manchester Metropolitain University, Yale University and The University of York also took part in the study.
Adapted from materials provided by University of Manchester.

Coralline Algae In The Mediterranean Lost Their Tropical Element Between 5 And 7 Million Years Ago

ScienceDaily (July 7, 2009) — An international team of researchers has studied the coralline algae fossils that lived on the last coral reefs of the Mediterranean Sea between 7.24 and 5.3 million years ago. Mediterranean algae and coral reefs began to resemble present day reefs following the isolation of the Mediterranean from the Indian Ocean and global cooling 15 and 20 million years ago respectively.
The research team from the University of Granada (UGR) and the University of Modena and Reggio Emilia (Italia) show coralline algae distribution patterns in the west and centre of the Mediterranean Sea (in Salento, Italy and Almería, Spain) by way of a fossil register of 21 species collected in the two areas.
"Coralline algae are calcareous algae that are very common nowadays, although unknown to the general public, including naturalists, and quite often in fossil form, particularly in relatively modern rocks", Juan C. Braga, the chief author and a researcher at the Stratigraphy and Paleontology Department of the UGR explained to SINC.
The study, which was published recently in Palaeogeography Palaeoclimatology Palaeoecology, describes and interprets the disappearance of the last Messinian coral reefs (between 7.24 and 5.3 million years ago) in the Mediterranean Sea. "In subsequent, more recent eras, this sea has not had the right oceanographic conditions (above all a high enough temperature) to house coral reefs," Braga added.
When Tropical Coral Reefs Became Atlantic
During the period studied by the scientists through the coralline algae fossils found in the Mediterranean, the last few reefs boasted very little coralline diversity. "This is the result of the long history of global cooling over the last 20 million years and the isolation (separation) of the Mediterranean from the Indian Ocean, some 15 million years ago," the research says.
According to the results of the research, the relative abundance of coralline algae in reefs and slope deposits is 1-5% and 18% lower respectively in the Sorbas basin (Almería) than in Salento (Italy). Furthermore, the main components of the coralline algae assemblages found in shallow water are extant species that are very common in the Mediterranean.
Other species, such as Spongites fruticulosus and Phymatolithon calcareum, have lived in the western Mediterranean for more than 25 million years. However, the typical components of present-day coral reefs, such as Hydrolithon species with thick thalli, which were no longer present in the western region of the Mediterranean 7 million years ago.
"Just like reef corallines, algae flora reflects the cooling of the Mediterranean and its isolation from the Indian Ocean, and only a few tropical biotas existed in the Messinian era. Moreover, most of them already had Atlantic affinities and resembled the algae that still inhabits our coasts today", Braga states.
The Mediterranean-Atlantic characteristics of Messinian reef corallines therefore reflect the decrease in tropical biotas that occurred during the Miocene (around 20 million years ago). According to the research team, the widespread decline of this type of algae was due to global cooling and the isolation of the Mediterranean during the middle Miocene.
Journal reference:
Braga et al. Coralline algae (Corallinales, Rhodophyta) in western and central Mediterranean Messinian reefs. Palaeogeography Palaeoclimatology Palaeoecology, 2009; 275 (1-4): 113 DOI: 10.1016/j.palaeo.2009.02.022
Adapted from materials provided by FECYT - Spanish Foundation for Science and Technology.

A DNA analysis was performed of shed hairs found in a book owned by Copernicus for decades.

ScienceDaily (July 7, 2009) — Swedish and polish researchers now publish results from the analysis of the putative remains of Copernicus. A DNA-analysis of shed hairs found in a book from Museum Gustavianum, Uppsala University, was one interesting piece in the project.
The efforts to identify the remains of Nicolaus Copernicus (1473-1543), found under the cathedral in Frombork, was made in a collaborative project between Swedish and Polish scientists in a team consisting of archaeologists, anthropologists and geneticists. The results is published this week in the journal PNAS (Proceedings of the National Academy of Sciences).
At Uppsala University a DNA analysis was performed of shed hairs found in a book owned by Copernicus for decades, and now kept in Museum Gustavianum at Uppsala University.
"The analysis of several hairs resulted in interpretable profiles for four of the hairs. Of these, two of the hairs have the same profile as the putative remains of Copernicus", says Marie Allen, researcher at Uppsala University.
The Uppsala researchers also made tests of a tooth as well as bone tissue from the putative remains of Copernicus. Results from the analysis of the remains from the Institute of Forensic Research in Krakow and the Museum and institute of zoology in Warsaw and the Uppsala laboratory were identical.
"Although these results points towards the materials being from the same individual, there is a probability of random match", says Marie Allen.
The DNA material in this case was limited and also degraded. Therefore, a so called mitochondrial DNA test was performed, which yields a relatively low evidentiary value. This test is commonly used in criminal investigations, but as circumstantial evidence to strengthen the case.
"The DNA results should be looked at and evaluated in the light of, and together with the information from other disciplines as the archaeological, anthropological and facial reconstruction data", says Marie Allen.
Adapted from materials provided by Uppsala University.

Largest Carnivorous Dinosaur Tooth Ever Found In Spain

ScienceDaily (July 7, 2009) — Researchers from the Teruel-Dinópolis Joint Palaeontology Foundation have compared an Allosauroidea tooth found in deposits in Riodeva, Teruel, with other similar samples. The palaeontologists have concluded that this is the largest tooth of a carnivorous dinosaur to have been found to date in Spain.
The features and size of the 9.83cm tooth provide key information needed to identify its former owner. The researchers are in no doubt – it was a large, predatory, carnivorous dinosaur (theropod) belonging to the Allosauroidea clade (one of the branches of the phylogenetic tree), a group that contains large carnivorous dinosaurs measuring between six and 15 meters.
"Given the great variations between the teeth of different kinds of allosauroids, it would be prudent for us to assign this fossil to an indeterminate Allosauroidea", Luis Alcalá, one of the researchers involved in the study to be published in the upcoming issue of Estudios Geológicos and managing director of the Teruel-Dinópolis Joint Palaeontology Foundation, tells SINC.
The tooth, found by local residents in Riodeva, Teruel, in the Villar del Arzobispo Formation, has been compared with other samples from the Allosauroidea group from the Iberian Peninsula – in particular with a large tooth from Portugal (measuring 12.7cm) and another belonging to an Allosauroidea indet in Spain, until now described as the largest in Spain at 8.27cm.
Working towards a complete faunal record of Riodeva
The palaeontologists say that "the presence of a large Allosauroidea is a great addition to the faunal record of the dinosaurs described in the Villar del Arzobispo Formation in Riodeva".
Plant-eating dinosaur groups (phytophages) discovered in the deposit to date have been identified as sauropods, stegosaurids and basal ornithopods (from tooth remains and a complete rear leg). "Now the carnivorous dinosaurs are also represented, at least by two medium-sized theropods and a large predator belonging to the Allosauroidea clade", adds Alcalá.
Carnivorous dinosaurs grew new teeth over their lifetimes, which increase the likelihood of finding them. In this case, the condition of the crown of the tooth found (without any reabsorption surfaces) indicates that it was not a discarded tooth. The palaeontologists hope to discover the remains of this large predator, which could have attacked Turiasaurus riodevensis, the 'European giant'.
Journal reference:
Royo-Torres et al. Diente de un gran dinosaurio terópodo (Allosauroidea) de la Formación Villar del Arzobispo (Titónico-Berriasiense) de Riodeva (España). Estudios Geológicos, 2009; DOI: 10.3989/egeol.39708.049
Adapted from materials provided by FECYT - Spanish Foundation for Science and Technology.

Underground Cave Dating From The Year 1 A.D. Exposed In Jordan Valley

ScienceDaily (July 7, 2009) — An artificial underground cave, the largest in Israel, has been exposed in the Jordan Valley in the course of a survey carried out by the University of Haifa's Department of Archaeology. Prof. Adam Zertal, who headed the excavating team, reckons that this cave was originally a large quarry during the Roman and Byzantine era and was a "one of a kind." Various engravings were uncovered in the cave, including cross markings, and it is assumed that this could have been an early monastery.
"It is probably the site of "Galgala" from the historical Madaba Map," Prof. Zertal says.
The enormous and striking cave covers an area of approximately 1 acre: it is some 100 meters long and about 40 meters wide. The cave is located 4 km north of Jericho. The cave, which is the largest excavated by man to be discovered in Israel, was exposed in the course of an archaeological survey that the University of Haifa has been carrying out since 1978.
As with other discoveries in the past, this exposure is shrouded in mystery. "When we arrived at the opening of the cave, two Bedouins approached and told us not to go in as the cave is bewitched and inhabited by wolves and hyenas," Prof. Zertal relates. Upon entering, accompanied by his colleagues, he was surprised to find an impressive architectonic underground structure supported by 22 giant pillars. They discovered 31 cross markings on the pillars, an engraving resembling the zodiac symbol, Roman letters and an etching that looks like the Roman Legion's pennant. The team also discovered recesses in the pillars, which would have been used for oil lamps, and holes to which animals that were hauling quarried stones out of the cave could have been tied.
The cave's ceiling is some 3 meters high, but was originally probably about 4 meters high. According to Prof. Zertal, ceramics that were found and the engravings on the pillars date the cave to around 1-600 AD. "The cave's primary use had been as a quarry, which functioned for about 400-500 years. But other findings definitely indicate that the place was also used for other purposes, such as a monastery and possibly as a hiding place," Prof. Zertal explains.
The main question that arose upon discovering the cave was why a quarry was dug underground in the first place. "All of the quarries that we know are above ground. Digging down under the surface requires extreme efforts in hauling the heavy rocks up to the surface, and in this case the quarrying was immense. The question is, why?"
For a possible answer to this mystery, Prof. Zertal points to the famous Madaba map. This is a Byzantine mosaic map that was found in Jordan and is the most ancient map of the Land of Israel. Jerusalem and the Jordan Valley are depicted with precision on the map, and a site called Galgala is depicted next to a Greek inscription that reads "Dodekaliton", which translates as "Twelve Stones." This place is marked at a distance from Jericho that matches this cave's distance from the city.
According to the map, there is a church next to Dodekaliton; there are two ancient churches located nearby the newly discovered cave. According to Prof. Zertal, until now it has been hypothesized that the meaning of "Twelve Stones" related to the biblical verses that describe the twelve stones that the Children of Israel place in Gilgal. However, it could be that the reference is a description of the quarry that was dug where the Byzantines identified the Gilgal.
"During the Roman era, it was customary to construct temples of stones that were brought from holy places, and which were therefore also more valuable stones. If our assumption is correct, then the Byzantine identification of the place as the biblical Gilgal afforded the site its necessary reverence and that is also why they would have dug an underground quarry there," Prof. Zertal concludes. "But" he adds, "much more research is needed."
Adapted from materials provided by University of Haifa, via EurekAlert!, a service of AAAS.

Friday, July 3, 2009

Triple Fossil Find Puts Australia Back On The Dinosaur Map

ScienceDaily (July 3, 2009) — Scientists have discovered three new species of Australian dinosaur discovered in a prehistoric billabong in Western Queensland.
Reporting on July 3 in the open-access, peer-reviewed journal, PLoS ONE, Scott Hocknull and colleagues at the Queensland Museum and the Australian Age of Dinosaurs Museum of Natural History describe the fossils of three new mid-Cretaceous dinosaurs from the Winton Formation in eastern Australia: two giant, herbivorous sauropods and one carnivorous theropod, all of which are to be unveiled in Queensland on July 3. The three fossils add to our knowledge of the Australian dinosaurian record, which is crucial for the understanding of the global paleobiogeography of dinosaurian groups.
Australia’s dinosaurian fossil record is extremely poor, compared with that of other similar-sized continents, such as South America and Africa. However, the mid-Cretaceous Winton Formation in central western Queensland has, in recent years, yielded numerous fossil sites with huge potential for the discovery of new dinosaurian taxa. Between 2006 and 2009, extensive excavations have yielded many well-preserved dinosaur fossils, as well as the remains of other contemporaneous fauna.
In a single, comprehensive, publication, Hocknull and colleagues describe the remains of three individual dinosaur skeletons, found during joint Australian Age of Dinosaurs Museum and Queensland Museum digs in two different sites in the Winton Formation. They represent three new genera and species of dinosaur: two giant herbivorous sauropods and a carnivorous theropod.
The carnivore, named by the authors on the paper Australovenator wintonensis (nicknamed “Banjo”) is the most complete meat-eating dinosaur found in Australia, to date and sheds light on the ancestry of the largest-ever meat-eating dinosaurs, the carcharodontosaurs, a group of dinosaurs that became gigantic, like Giganotosaurus.
“The cheetah of his time, Banjo was light and agile,” said lead author Scott Hocknull. “He could run down most prey with ease over open ground. His most distinguishing feature was three large slashing claws on each hand. Unlike some theropods that have small arms (think T. rex), Banjo was different; his arms were a primary weapon.
“He’s Australia's answer to Velociraptor, but many times bigger and more terrifying.”
The skeleton of Australovenator solves a 28-year-old mystery surrounding an ankle bone found in Victoria, which was originally classified as a dwarf Allosaurus, although this classification remained controversial until the discovery of Australovenator—the researchers are now able to confirm that the ankle bone belonged to the lineage that led to Australovenator.
The two plant-eating theropods, named Witonotitan wattsi (“Clancy”) and Diamantinasaurus matildae (“Matilda”), are different kinds of titanosaur (the largest type of dinosaur ever to have lived). While Witonotitan represents a tall, gracile animal, which might have fitted into a giraffe-like niche, the stocky, solid Diamantinasaurus represents a more hippo-like species.
All three dinosaurs are nicknamed after characters from a world-famous, Australian poet. Banjo Patterson composed Waltzing Matilda in 1885 in Winton, where the song was also first performed (and where the fossils were discovered). Waltzing Matilda is now considered to be Australia’s national song.
In a quirky twist of fate, the song Waltzing Matilda describes the unfortunate demise of a swag-man, who steals a jumbuck (sheep) but is driven to leap into a billabong (an Australian word for a small oxbow lake) to avoid being captured by the police. He ends up drowning in the billabong alongside the stolen sheep.
Banjo and Matilda were found buried together in what turns out to be a 98-million-year-old billabong. Whether they died together or got stuck in the mud together remains a mystery; however, echoing the song, both predator and possible prey met their end at the bottom of a billabong, 98 million years ago. This shows that processes that were working in the area over the last 98 million years are still there today. “Billabongs are a built-in part of the Australian mind,” said Hocknull, “because we associate them with mystery, ghosts and monsters.”
The finding and documentation of the fossils was a 100% Australian effort. Both Matilda and Banjo were prepared by Australian Age of Dinosaurs Museum thanks to thousands of hours of volunteer work and philanthropy.
“This is the only place in Australia where you can come off the street and be taught to be a palaeontologist and find, excavate and prepare your own part of Australian natural history,” said Hocknull. The dinosaurs will now be part of a museum collection and this effort will enable future generations of scientists to be involved in a new wave of dinosaur discoveries and to bring the general public in touch with their own natural heritage.”
This collaborative effort links closely with PLoS ONE’s philosophy of making science freely accessible to the general public. “One of my major motivations for submitting to PLoS ONE was the fact that my research will reach a much wider community, including the hundreds of volunteers and public who gave their time and money to the development of natural history collections,” said Hocknull. “They are the backbone of our work (excuse the pun) and they usually never get to see their final product because they rarely subscribe to scientific journals.”
All three new taxa, along with some fragmentary remains from other taxa, indicate a diverse Early Cretaceous sauropod and theropod fauna in Australia, and the finds will help provide a better understanding of the Australian dinosaurian record, which is, in turn, crucial for the understanding of the global palaeobiogeography of dinosaurian groups.
The authors agree that even though hundreds of bones have already been found at the site, these fossils are just the tip of the iceberg. “Many hundreds more fossils from this dig await preparation and there is much more material left to excavate,” they said. Australian Age of Dinosaurs Museum and Queensland Museum staff and volunteers will continue to dig at this and other sites in 2010.
The fossils will be unveiled at the Australian Age of Dinosaurs Museum of Natural History in Queensland, Australia, July 3 by Anna Bligh, the Premier of Queensland. Stage 1 of the museum, a non-profit, volunteer-driven, science initiative that aims to bring Australian dinosaurs to the world, will also be opened by Ms Bligh on July 3.
Journal reference:
Scott A. Hocknull, Matt A. White, Travis R. Tischler, Alex G. Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott. New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia. PLoS ONE, 2009; 4 (7): e6190 DOI: 10.1371/journal.pone.0006190
Adapted from materials provided by Public Library of Science.

Wednesday, July 1, 2009

Dino Tooth Sheds New Light On Ancient Riddle: Major Group Of Dinosaurs Had Unique Way Of Eating

ScienceDaily (June 30, 2009) — Microscopic analysis of scratches on dinosaur teeth has helped scientists unravel an ancient riddle of what a major group of dinosaurs ate -- and exactly how they did it!
Now for the first time, a study led by the University of Leicester, has found evidence that the duck-billed dinosaurs -- the Hadrosaurs -- in fact had a unique way of eating, unlike any living creature today.
Working with researchers from the Natural History Museum, the study uses a new approach to analyse the feeding mechanisms of dinosaurs and understand their place in the ecosystems of tens of millions of years ago. The results are published today in the Proceedings of the National Academy of Sciences.
Palaeontologist Mark Purnell of the University of Leicester Department of Geology, who led the research, said: "For millions of years, until their extinction at the end of the Cretaceous, duck-billed dinosaurs – or hadrosaurs - were the World's dominant herbivores. They must have been able to break down their food somehow, but without the complex jaw joint of mammals they would not have been able to chew in the same way, and it is difficult to work out how they ate. It is also unclear what they ate: they might have been grazers, cropping vegetation close to the ground - like today's cows and sheep - or browsers, eating leaves and twigs - more like deer or giraffes. Not knowing the answers to these questions makes it difficult to understand Late Cretaceous ecosystems and how they were affected during the major extinction event 65 million years ago.
"Our study uses a new approach based on analysis of the microscopic scratches that formed on hadrosaur's teeth as they fed, tens of millions of years ago. The scratches have been preserved intact since the animals died. They can tell us precisely how hadrosaur jaws moved, and the kind of food these huge herbivores ate, but nobody has tried to analyse them before."
The researchers say that the scratches reveal that the movements of hadrosaur teeth were complex and involved up and down, sideways and front to back motion. According to Paul Barrett palaeontologist at the Natural History Museum "this shows that hadrosaurs did chew, but in a completely different way to anything alive today. Rather than a flexible lower jaw joint, they had a hinge between the upper jaws and the rest of the skull. As they bit down on their food the upper jaws were forced outwards, flexing along this hinge so that the tooth surfaces slid sideways across each other, grinding and shredding food in the process".
The scratch patterns provide confirmation of a theory of hadrosaur chewing first proposed 25 years ago, and provides new insights into their ecology, say the researchers.
The research also sheds light on what the dinosaurs ate. Vince Williams of the University of Leicester said: "Although the first grasses had evolved by the Late Cretaceous they were not common and it is most unlikely that grasses formed a major component of hadrosaur diets. We can tell from the scratches that the hadrosaur's food either contained small particles of grit, normal for vegetation cropped close to the ground, or, like grass, contained microscopic granules of silica. We know that horsetails were a common plant at the time and have this characteristic; they may well have been an important food for hadrosaurs".
One of the big surprises of this study is that so much information about such large animals can be gleaned from such a tiny patch of tooth. "By looking at the pattern of scratches in an area that is only about as wide as a couple of human hairs we can work out how and what these huge herbivores were eating" notes Williams. "And because we can analyse single teeth, rather than whole skeletons, the technique has the potential to tell us a lot more about dinosaur feeding and the ecosystems in which they lived."
1. The erroneous idea that all dinosaurs could chew is so widely accepted that the memorable 'Chewits' advertising campaigns of the 1980s were based on the idea. Note that the dinosaur shown in the adverts is not a hadrosaur:
2. The paper "Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding" by Vincent S. Williams, Paul M. Barrett and Mark A. Purnell is published in the Proceedings of the National Academy of Sciences (online Early Edition).
3. This study is based on Edmontosaurus: Lived USA and Canada 65-68 million years ago; Length up to 13 m, weight up to 3 tonnes; One of the most abundant dinosaurs of its time; Known from many complete skeletons, including several mummies with skin impressions and gut contents preserved.
Adapted from materials provided by University of Leicester, via EurekAlert!, a service of AAAS.

New Fossil Primate Suggests Common Asian Ancestor, Challenges Primates Such As 'Ida'


ScienceDaily (July 1, 2009) — According to new research published online in the Proceedings of the Royal Society B (Biological Sciences) on July 1, 2009, a new fossil primate from Myanmar (previously known as Burma) suggests that the common ancestor of humans, monkeys and apes evolved from primates in Asia, not Africa as many researchers believe.
A major focus of recent paleoanthropological research has been to establish the origin of anthropoid primates (monkeys, apes and humans) from earlier and more primitive primates known as prosimians (lemurs, tarsiers and their extinct relatives). Prior to recent discoveries in China, Thailand, and Myanmar, most scientists believed that anthropoids originated in Africa. Earlier this year, the discovery of the fossil primate skeleton known as "Ida" from the Messel oil shale pit in Germany led some scientists to suggest that anthropoid primates evolved from lemur-like ancestors known as adapiforms.
According to Dr. Chris Beard–– a paleontologist at Carnegie Museum of Natural History in Pittsburgh, Pennsylvania and a member of the international team of researchers behind the Myanmar anthropoid findings––the new primate, Ganlea megacanina, shows that early anthropoids originated in Asia rather than Africa. These early Asian anthropoids differed radically from adapiforms like Ida, indicating that Ida is more closely related to modern lemurs than it is to monkeys, apes and humans.
The 38-million-year-old Ganlea megacanina fossils, excavated at multiple sites in central Myanmar, belong to a new genus and species. The name of the new species refers to a small village, Ganle, near the original site where the fossils were found, and the greatly enlarged canine teeth that distinguish the animal from closely related primates. Heavy dental abrasion indicates that Ganlea megacanina used its enlarged canine teeth to pry open the hard exteriors of tough tropical fruits in order to extract the nutritious seeds contained inside.
"This unusual type of feeding adaptation has never been documented among prosimian primates, but is characteristic of modern South American saki monkeys that inhabit the Amazon Basin," says Dr. Beard. "Ganlea shows that early Asian anthropoids had already assumed the modern ecological role of modern monkeys 38 million years ago."
Ganlea and its closest relatives belong to an extinct family of Asian anthropoid primates known as the Amphipithecidae. Two other amphipithecids, Pondaungia and Myanmarpithecus, were previously discovered in Myanmar, while a third, named Siamopithecus, had been found in Thailand. A detailed analysis of their evolutionary relationships shows that amphipithecids are closely related to living anthropoids and that all of the Burmese amphipithecids evolved from a single common ancestor. Some scientists had previously argued that amphipithecids were not anthropoids at all, being more closely related to the lemur-like adapiforms.
The discovery of Ganlea strongly supports the idea that amphipithecids are anthropoids, because adapiforms never evolved the features that are necessary to become specialized seed predators. Indeed, all of the Burmese amphipithecids appear to have been specialized seed predators, filling the same ecological niche occupied by modern pitheciine monkeys in the Amazon Basin of South America. During the Eocene when Ganlea and other amphipithecids were living in Myanmar, they inhabited a tropical floodplain that was very similar to the environment of the modern Amazon Basin.
Fossils of Ganlea megacanina were first discovered in Myanmar in December 2005. The fieldwork is a long-term collaboration by scientists from several institutions in Myanmar; as well as the University of Poitiers and the University of Montpellier in France; Carnegie Museum of Natural History in Pittsburgh, PA; and the Department of Mineral Resources in Bangkok, Thailand. Funding was provided by the U.S. National Science Foundation and the Centre National de la Recherche Scientifique in France.
Adapted from materials provided by Carnegie Museum of Natural History.

Tuesday, June 23, 2009

Indonesian elephant fossil opens window to past


Scientists arrange the bones of an estimated 200,000 year-old giant elephant at Geology Museum in Bandung, West Java, Indonesia, Thursday, June 18, 2009. Indonesian scientists are reconstructing the largest, most complete skeleton of an ancient elephant ever found in the tropics, a finding that may offer new clues into the largely mysterious origins of its modern Asian cousin. Based on the fossil, the ancient elephant stood four meters (13-feet) tall, was five meters (16-feet) long and weighed more than 10 tons, considerably larger than the great Asian mammals now on Earth. (AP Photo/Dita Alangkara)
(AP) -- Indonesian scientists are reconstructing the largest, most complete skeleton of a prehistoric giant elephant ever found in the tropics, a finding that may offer new clues into the largely mysterious origins of its modern Asian cousin.
The prehistoric elephant is believed to have been submerged in quicksand shortly after dying on a riverbed in Java around 200,000 years ago. Its bones - almost perfectly preserved - were discovered by chance in March when an old sand quarry collapsed during monsoon rains.
The animal stood four meters (13-feet) tall, five meters (16-feet) long and weighed more than 10 tons - closer in size to the woolly mammoth of the same period than to the great Asian mammals now on Earth.
Animal fossils are rare in the humid, hot climate of the equator because decomposition occurs extremely quickly.
Following a monthlong excavation, a team of seven paleontologists from the Museum in Bandung, West Java, set the bones in plaster for the trip back to their office where they will be laboriously pieced back together.
"We believe from the shape of its teeth that it was a very primitive elephant," but little else has been verified, said paleontologist Fachroel Aziz, who is heading a 12-strong skeletal reconstruction team.
Scientists agree it is the first time an entire prehistoric elephant has been unearthed since vertebrate findings began to be recorded in Indonesia in 1863.
"It is very uncommon to discover a fossil like this in a tropical region like Indonesia," said Edi Sunardi, an independent expert at Indonesia's Pajajaran University in Bandung, West Java. "It apparently was covered by volcanic sediment that protected it from high temperatures, erosion and decay."
The next challenge will be removing the delicate bones from their molds and joining them into a stable, upright structure, a process that experts said is already being hampered by a lack of funding, inadequate tools and poor expertise.
Indonesia, an emerging and impoverished democracy of 235 million people, cannot afford to allocate more than a token sum to its aging museums, even for projects that have the potential to advance knowledge about the origin of key native species.
Gert van den Berg, a researcher at Australia's Wollongong University who helped dig up the skeleton, said tests are under way to determine its precise age and species, and that they will help provide details "about when the modern evolved into what they are now."
About 2,000 old elephant remains have been found across the island nation over the past 150 years, but never in such good condition, Aziz said.
"We want to exhibit it publicly because this is a spectacular discovery," he said.

Cold Case Techniques Bring Mummy’s Face To 'Life'


ScienceDaily (June 23, 2009) — Thanks to the skills of artists who work on cold case investigations, people have a chance to see what the University of Chicago’s mummy Meresamun may have looked like in real life.
A Chicago forensic artist and a police artist in Maryland prepared the images, which depict an engaging woman in her late 20s as she would have looked in 800 B.C. Both artists, though working independently, produced strikingly similar images.*
Dr. Michael Vannier, Professor of Radiology, began the process of restoring the mummy’s facial features with two exhaustive CT examinations of Meresamun in 2008 at the University of Chicago Medical Center.
“A huge number of CT scans of the skull were used to create a 3-D digital model of Meresamun’s skull,” said Emily Teeter, Research Associate at the Oriental Institute an curator of a museum exhibition about the mummy. “Those files were given to forensic artists who use methods employed in cold case investigations where skeletal remains need to be identified.”
The Oriental Institute wanted to compare multiple reconstructions, in order to obtain a trustworthy image of Meresamun’s face. Both a digital version of the traditional forensic reconstruction and a missing person-type sketch were submitted.
In the traditional forensic method, layers of fat, muscle and flesh are built up upon the skull. Starting with a three-dimensional image of the skull created from multiple CT scans, Chicago artist Joshua Harker used a technique known as the Gatliff-Snow American Tissue Depth Marker Method to calculate the contours of the face to digitally recreate Meresamun’s appearance.
“The skull is the driving architecture of the face—all the proportions and placements are there, if know how to read it,” Harker explained. “Even the shapes of the lips, nose and eyebrows can be determined if you know what to look for,” The American Tissue Depth Marker method has been shown to be effective in accurately reconstructing a face, both in identifying victims and as admissible evidence in court.
“I try not to make any assumptions without expert direction, whether that be from an anthropologist regarding the race, gender or age, or from and expert like Emily Teeter who can give me an accurate description about details based on historical evidence,” Harker said. “I am ecstatic that my reconstruction of Meresamun has been so well received by the community who knows the most about her.”
Michael Brassell, who works with the Department of Justice/Maryland State Police Missing Persons Unit, used his skills as a trained sketch artist to produce a second, more traditional reconstruction.
“The project was no different then any of the postmortems drawings I have worked on for cold case homicides. The CT scans were very clear, making my job easy,” he said. “If this was a homicide case, I would almost go as far to guarantee a hit on the profile drawing.”
Meresamun lived in Thebes (ancient Luxor) about 800 B.C. and died of undetermined causes about age 29-30. An exhibit, “The Life of Meresamun: A Temple Singer in Ancient Egypt,” features her mummy and coffin and will be featured through Dec. 6 at the Oriental Institute Museum. A video display allows visitors to view features of Meresamun’s physical state and perform a “virtual unwrapping” of the mummy, enabling them to see how it was prepared. Advanced digital techniques have made it possible to recreate Meresamun’s appearance.
She was tall by ancient standards—5-and-a-half feet—her features were regular with wide-spaced eyes and she had an overbite. “Meresamun was, until the time of her death at about 30, a very healthy woman,” Vannier said. “The lack of arrest lines on her bones indicates good nutrition through her lifetime and her well-mineralized bones suggest that she lived an active lifestyle.”
*The drawings are on display at the Oriental Institute Museum, and have been placed on the institute’s Web site (, on Meresamun’s Facebook page, her Wikipedia listing and on YouTube.
Adapted from materials provided by University of Chicago.

54-million-year-old Skull Reveals Early Evolution Of Primate Brains


ScienceDaily (June 23, 2009) — Researchers at the University of Florida and the University of Winnipeg have developed the first detailed images of a primitive primate brain, unexpectedly revealing that cousins of our earliest ancestors relied on smell more than sight.
The analysis of a well-preserved skull from 54 million years ago contradicts some common assumptions about brain structure and evolution in the first primates. The study also narrows the possibilities for what caused primates to evolve larger brain sizes. The study is scheduled to appear online the week of June 22 in the Proceedings of the National Academy of Sciences.
The skull belongs to a group of primitive primates known as Plesiadapiforms, which evolved in the 10 million years between the extinction of the dinosaurs and the first traceable ancestors of modern primates. The 1.5-inch-long skull was found fully intact, allowing researchers to make the first virtual mold of a primitive primate brain.
"Most explanations on the evolution of primate brains are based on data from living primates," said lead author Mary Silcox, an anthropologist at the University of Winnipeg and research associate at UF's Florida Museum of Natural History. "There have been all these inferences about what the brains of the earliest primates would look like, and it turns out that most of those inferences are wrong."
Researchers used CT scans to take more than 1,200 cross-sectional X-ray images of the skull, which were combined into a 3-D model of the brain.
"A large and complex brain has long been regarded as one of the major steps that sets primates apart from the rest of mammals," said Florida Museum vertebrate paleontologist and study co-author Jonathan Bloch. "At our very humble beginnings, we weren't so special. That happened over tens of millions of years."
The animal, Ignacius graybullianus, represents a side branch on the primate tree of life, Bloch said. "You can think of it as a cousin of the main line lineage that would have given rise ultimately to us."
In previous research, Bloch and Silcox established that Plesiadapiforms were transitional species. Ignacius was similar to modern primates in terms of its diet and tree-dwelling but did not leap from tree to tree like modern fast-moving primates.
In many ways, the early primate behaved like living primates but with a brain that was one-half to two-thirds the size of the smallest modern primates. This means that factors such as tree-dwelling and fruit-eating can be eliminated as potential causes for primates evolving larger brain sizes, Silcox said, because "the smaller brained Ignacius was already doing those things."
The mold suggests a "startling combination" of features in the early primate that requires a rethinking of primate brain evolution, said Florida State University anthropologist Dean Falk, who was not involved in the study.
"Hypotheses about early primate brain evolution often link keen smell with nocturnal insect-eating, and a more recently evolved increase in visual processing with fruit-eating in arboreal habitats," Falk said.
The move to larger brain size occurred during an evolutionary burst that happened 10 million years after the extinction of the dinosaurs. At that point, visual features in the brain became much more prominent while the olfactory bulbs became proportionately smaller.
More than likely, Bloch said, this change in brain structure and size was related to primates living in closed canopy forests that brought trees closer together and allowed for more leaping. But answering that will require the discovery and analysis of new fossils.
Changes in brain size and brain structure in the early stages of primate evolution have generated enormous debates for decades. But until now, fossil evidence has been lacking.
Many models of the ancestral primate brain are based on tree shrews, which come from southeast Asia and are distantly related to humans. But with some 70 million years of evolution between them and humans, "it turns out tree shrew brains are not a good model," Silcox said.
Adapted from materials provided by University of Florida.

Monday, June 22, 2009

Obsidian 'trail' provides clues to how humans settled, interacted in Kuril Islands


Tiny obsidian flakes such as this found in the Kuril Islands have been traced to their source on Japan's Hokkaido Island and Russia's Kamchatka Peninsula.
( -- Archaeologists have used stone tools to answer many questions about human ancestors in both the distant and near past and now they are analyzing the origin of obsidian flakes to better understand how people settled and interacted in the inhospitable Kuril Islands.
Using X-ray fluorescence spectrometers, archaeologists from the University of Washington and the Smithsonian Institution have found the origin of 131 flakes of obsidian, a volcanic glass. These small flakes were discarded after stone tools were made from obsidian and were found at 18 sites on eight islands in the Kurils. The flakes were found with other artifacts that were dated over a time period spanning about 1,750 years, from 2500 to 750 years before the present.
The Kuril Archipelago stretches for nearly 800 miles between the northern-most Japanese island of Hokkaido and the Kamchatka Peninsula in Russia. Despite the islands' volcanic origin, there are no known local sources of obsidian.
"A key quality of obsidian is you can create very sharp edge. Obsidian flakes easily and fractures in a way that is predictable. When it was available have used it," said Colby Phillips, lead author of the new study and an anthropology doctoral student at the University of Washington. His co-author is Robert Speakman of the Smithsonian's Museum Conservation Institute.
Obsidian is formed when magma is extruded from a volcano and can be geochemically identified Phillips said. That's because the obsidian from each volcano has a unique based on the amount of elements such as rubidium, zirconium and strontium in the glass. Archaeologists gather obsidian samples from volcanoes to create a data base of chemical signatures and compare archaeological samples collected in the field to the data base.
Phillips and Speakman pinpointed the Kuril flakes they analyzed to four locations on Hokkaido and five sources on Kamchatka. The majority of the flakes, slightly more than 60 percent, originated in Kamchatka.
Human occupation of the Kurils began about 4,000 years ago at the southern end of the island chain near Hokkaido and gradually spread northward. And where humans went they carried obsidian with them.
"Obsidian only makes up about 8 percent of the stone tools and the waste left from their manufacture, but it shows up at all sites and over all time periods," said Phillips. "Obsidian may have played a role in maintaining social and trade networks as people migrated across the Kurils. Our work suggests social relationships can be important in local and regional areas. Here we have people living in an isolated area that is covered by fog and clouds and subject to tsunamis, volcanic eruptions and earthquakes. So it would be advantageous to have connections with other people. The fact that we have a material such as obsidian throughout the islands shows people were proactive in maintaining ties in the prehistoric era."
The researchers found a basic pattern of obsidian distribution in the islands. Obsidian from Hokkaido was primarily found in the Southern Kurils with a few samples discovered in the Central Kurils. Kamchatka obsidian was only found in the Central and Northern Kurils.
The Southern Kurils are separated from the other islands in the chain by the 70-mile-wide Bussol Strait. Phillips believes that at some time it became too costly to make the dangerous ocean crossing, and people in the central and northern began trading for Kamchatka obsidian.
Since the research was accepted for publication, Phillips and Speakman have analyzed the sources of an additional 700 obsidian flakes and their results mirror the newly published data.
Source: University of Washington (news : web)