Indonesian elephant fossil opens window to past

SOURCE

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 Geology 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 skeleton has been unearthed since vertebrate fossil 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 elephants 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'

SOURCE

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 (http://oi.uchicago.edu/museum/special/meresamun/), 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

SOURCE

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.

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

SOURCE

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.

(PhysOrg.com) -- 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 people 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 chemical signature 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 islands 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)

Dinosaurs May Have Been Smaller Than Previously Thought

SOURCE

ScienceDaily (June 22, 2009) — The largest animals ever to have walked the face of the earth may not have been as big as previously thought, reveals a paper published June 21 in the Zoological Society of London’s Journal of Zoology.

Scientists have discovered that the original statistical model used to calculate dinosaur mass is flawed, suggesting dinosaurs have been oversized.
Widely cited estimates for the mass of Apatosaurus louisae, one of the largest of the dinosaurs, may be double that of its actual mass (38 tonnes vs. 18 tonnes).
"Paleontologists have for 25 years used a published statistical model to estimate body weight of giant dinosaurs and other extraordinarily large animals in extinct lineages. By re-examining data in the original reference sample, we show that the statistical model is seriously flawed and that the giant dinosaurs probably were only about half as heavy as is generally believed" says Gary Packard from Colorado State University.
The new predictions have implications for numerous theories about the biology of dinosaurs, ranging from their energy metabolism to their food requirements and to their modes of locomotion.
Journal reference:
. Allometric equations for predicting body mass of dinosaurs. Journal of Zoology, June 21, 2009 DOI: 10.1111/j.1469-7998.2009.00594.x
Adapted from materials provided by Wiley - Blackwell, via AlphaGalileo.

Ice Sheets Can Retreat 'In A Geologic Instant,' Study Of Prehistoric Glacier Shows

SOURCE

ScienceDaily (June 22, 2009) — Modern glaciers, such as those making up the Greenland and Antarctic ice sheets, are capable of undergoing periods of rapid shrinkage or retreat, according to new findings by paleoclimatologists at the University at Buffalo.

The paper, published on June 21 in Nature Geoscience, describes fieldwork demonstrating that a prehistoric glacier in the Canadian Arctic rapidly retreated in just a few hundred years.
The proof of such rapid retreat of ice sheets provides one of the few explicit confirmations that this phenomenon occurs.
Should the same conditions recur today, which the UB scientists say is very possible, they would result in sharply rising global sea levels, which would threaten coastal populations.
"A lot of glaciers in Antarctica and Greenland are characteristic of the one we studied in the Canadian Arctic," said Jason Briner, Ph.D., assistant professor of geology in the UB College of Arts and Sciences and lead author on the paper. "Based on our findings, they, too, could retreat in a geologic instant."
The new findings will allow scientists to more accurately predict how global warming will affect ice sheets and the potential for rising sea levels in the future, by developing more robust climate and ice sheet models.
Briner said the findings are especially relevant to the Jakobshavn Isbrae, Greenland's largest and fastest moving tidewater glacier, which is retreating under conditions similar to those he studied in the Canadian Arctic.
Acting like glacial conveyor belts, tidewater glaciers are the primary mechanism for draining ice sheet interiors by delivering icebergs to the ocean.
"These 'iceberg factories' exhibit rapid fluctuations in speed and position, but predicting how quickly they will retreat as a result of global warming is very challenging," said Briner.
That uncertainty prompted the UB team to study the rates of retreat of a prehistoric tidewater glacier, of similar size and geometry to contemporary ones, as way to get a longer-term view of how fast these glaciers can literally disappear.
The researchers used a special dating tool at UB to study rock samples they extracted from a large fjord that drained the ice sheet that covered the North American Arctic during the past Ice Age.
The samples provided the researchers with climate data over a period from 20,000 years ago to about 5,000 years ago, a period when significant warming occurred.
"Even though the ice sheet retreat was ongoing throughout that whole period, the lion's share of the retreat occurred in a geologic instant -- probably within as little as a few hundred years," said Briner.
The UB research reveals that the period of rapid retreat was triggered once the glacier entered deep ocean waters, nearly a kilometer deep, Briner said.
"The deeper water makes the glacier more buoyant," he explained.
"Because the rates of retreat were so much higher in the deep fjord, versus earlier when it terminated in more shallow waters or on land, the findings suggest that contemporary tidewater glaciers in Greenland and Antarctica that are retreating into deep waters may begin to experience even faster rates of retreat than are currently being observed," said Briner.
Right now, Jakobshavn Isbrae is draining into waters that are nearly a kilometer deep, he said, which means that its current rates of retreat -- as fast as 10 kilometers in the past decade -- could continue for the next hundred years.
"If modern glaciers do this for several decades, this would rapidly raise global sea level, intercepting coastal populations and requiring vast re-engineering of levees and other mitigation systems," said Briner.
Co-authors on the paper were Aaron C. Bini, formerly a master's of science candidate in the UB Department of Geology, and Robert S. Anderson, Ph.D., in the Department of Geological Sciences at the University of Colorado, Boulder.
Briner's research was funded by the National Science Foundation.
Adapted from materials provided by University at Buffalo.

Sudden Collapse In Ancient Biodiversity: Was Global Warming The Culprit?

SOURCE

ScienceDaily (June 19, 2009) — Scientists have unearthed striking evidence for a sudden ancient collapse in plant biodiversity. A trove of 200 million-year-old fossil leaves collected in East Greenland tells the story, carrying its message across time to us today.

Results of the research appear in the journal Science.
The researchers were surprised to find that a likely candidate responsible for the loss of plant life was a small rise in the greenhouse gas carbon dioxide, which caused Earth's temperature to rise.
Global warming has long been considered as the culprit for extinctions--the surprise is that much less carbon dioxide gas in the atmosphere may be needed to drive an ecosystem beyond its tipping point than previously thought.
"Earth's deep time climate history reveals startling discoveries that shake the foundations of our knowledge and understanding of climate change in modern times," says H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which partially funded the research.
Jennifer McElwain of University College Dublin, the paper's lead author, cautions that sulfur dioxide from extensive volcanic emissions may also have played a role in driving the plant extinctions.
"We have no current way of detecting changes in sulfur dioxide in the past, so it's difficult to evaluate whether sulfur dioxide, in addition to a rise in carbon dioxide, influenced this pattern of extinction," says McElwain.
The time interval under study, at the boundary of the Triassic and Jurassic periods, has long been known for its plant and animal extinctions.
Until this research, the pace of the extinctions was thought to have been gradual, taking place over millions of years.
It has been notoriously difficult to tease out details about the pace of extinction using fossils, scientists say, because fossils can provide only snap-shots or glimpses of organisms that once lived.
Using a technique developed by scientist Peter Wagner of the Smithsonian Institution National Museum of Natural History in Washington, D.C., the researchers were able to detect, for the first time, very early signs that these ancient ecosystems were already deteriorating--before plants started going extinct.
The method reveals early warning signs that an ecosystem is in trouble in terms of extinction risk.
"The differences in species abundances for the first 20 meters of the cliffs [in East Greenland] from which the fossils were collected," says Wagner, "are of the sort you expect. "But the final 10 meters show dramatic loses of diversity that far exceed what we can attribute to sampling error: the ecosystems were supporting fewer and fewer species."
By the year 2100, it's expected that the level of carbon dioxide in the modern atmosphere may reach as high as two and a half times today's level.
"This is of course a 'worst case scenario,'" says McElwain. "But it's at exactly this level [900 parts per million] at which we detected the ancient biodiversity crash.
"We must take heed of the early warning signs of deterioration in modern ecosystems. We've learned from the past that high levels of species extinctions--as high as 80 percent--can occur very suddenly, but they are preceded by long interval of ecological change."
The majority of modern ecosystems have not yet reached their tipping point in response to climate change, the scientists say, but many have already entered a period of prolonged ecological change.
"The early warning signs of deterioration are blindingly obvious," says McElwain. "The biggest threats to maintaining current levels of biodiversity are land use change such as deforestation. "But even relatively small changes in carbon dioxide and global temperature can have unexpectedly severe consequences for the health of ecosystems."
The paper was co-authored by McElwain, Wagner and Stephen Hesselbo of the University of Oxford in the U.K.
Journal reference:
. Fossil Plant Relative Abundances Indicate Sudden Loss of Late Triassic Biodiversity in East Greenland. Science, June 18, 2009
Adapted from materials provided by National Science Foundation.