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New Texas Native: 96-million-year-old crocodile Terminonaris makes its first appearance in Texas, switches origins

Rare find alters origins and distribution of Terminonaris; first home was Texas and North America — not Europe

http://www.youtube.com/watch?v=oHS6vE4o3XY

Making its first appearance in Texas, a prehistoric crocodile thought to have originated in Europe now appears to have been a native of the Lone Star State.

The switch in origins for the genus known as Terminonaris is based on the identification of a well-preserved, narrow fossil snout that was discovered along the shoreline of a lake near Dallas.

The 96-million-year-old fossil from Texas is the oldest prehistoric crocodile of its kind in the world, according to paleontologist Thomas L. Adams at Southern Methodist University, Dallas, who identified the reptile.

A distant cousin of modern crocodiles and alligators, Terminonaris was similar to the modern-day Indian gharial, only much larger.

“With the recognition of Terminonaris here in Texas, this actually changes a lot about what we thought we knew about this group,” Adams said.

“Now we know the group had a wider distribution range, and that it’s much older. It represents a unique find for Texas. This is the first occurrence of Terminonaris in Texas. It’s also the oldest occurrence of Terminonaris in the world, and it’s also the southernmost occurrence of Terminonaris anywhere.”

There are six other known Terminonaris fossil specimens: five from North America and one from Europe. The European specimen, from Germany, previously was thought to be the oldest. Scientists had concluded that Terminonaris originated in Europe and then traversed the Atlantic and dispersed throughout North America.

“Now we know Terminonaris most likely originated here in Texas and dispersed northward,” said Adams, a doctoral candidate in SMU’s Roy M. Huffington Department of Earth Sciences at SMU.

Big Texas crocodile swam the shores of North America’s prehistoric seaway
Adams identified the reptile primarily from its long snout, which measures more than 2 feet long and 7 inches wide, or 62 centimeters. With a snout that long, Adams estimates the head would have been about one meter long.

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“Based on Nile crocodiles and the Indian gharial, which are both large crocodiles, a regression analysis indicates this Terminonaris probably would have been 23 to 25 feet long,” said Adams. “The largest living crocodile today is the saltwater crocodile, which can reach up to 20 feet in length.”

The Texas Terminonaris was an adult and most likely weighed more than a ton, he said.

Adams identified the fossils in “First Occurrence of the Long-Snouted Crocodyliform Terminonaris (Pholidosauridae) from the Woodbine Formation (Cenomanian) of Texas” in the Journal of Vertebrate Paleontology.

Prehistoric crocodiles such as Terminonaris together with living crocodiles make up a large group called crocodyliformes. While technically there are differences between living crocodiles and each of the different types of fossil crocodile forms, all of them are often commonly referred to as crocodiles.

Today there are only 23 species of living crocodiles, a small number compared to the many species of mammals, birds, lizards, snakes and fish alive today, Adams said. That’s in stark contrast to prehistoric times.

“In the past, the crocodilian forms were very diverse and they were very successful. There were hundreds of species. Even at the time of the Texas Terminonaris, they were found everywhere,” Adams said.

Texas specimen fills gap, expands age and range of group
Texas Terminonaris was discovered by Dallas-area amateur fossil enthusiast Brian Condon, a rural mail carrier. Condon discovered the heavy pieces of the snout and a vertebrate in 2005 while fossil hunting near his home on Lake Lewisville, a 26,000-acre recreational and fishing lake managed by the U.S. Army Corps of Engineers. He spotted the first of the pieces along the shoreline. Condon donated the fossils to SMU’s Shuler Museum of Paleontology.

In prehistoric times, Texas Terminonaris would have made its home in a marine setting, along the eastern shore of North America’s vast prehistoric Western Interior Seaway. One hundred million years ago the seaway was a wide, shallow sea that split the North American continent in half from the Arctic to the Gulf of Mexico, said Adams, lead author on the scientific article. The seaway would have covered Lake Lewisville’s location.

In its day-to-day life on the seaway, Terminonaris would have kept close to shore, perhaps in a shallow lagoon or estuary, also venturing into the seaway’s warm salty water to hunt for fish. Like modern crocodiles and alligators, Terminonaris would have eaten whatever it could catch, Adams said. Its long, slender snout was well-suited for devouring fish, small mammals and even small dinosaurs.

North America’s other Terminonaris fossil specimens also were found along the seaway. A Kansas specimen is the youngest, about 91 million years, while those from Saskatchewan, Canada, and Montana are 93 million years old. The German specimen is 94 million years old.

“Terminonaris now here in Texas fills in a gap that we didn’t have information for,” Adams said. “It tells us that as a group, as a genus, they were around much longer, because we extend the age back to 96 million years. The range for them is now expanded, because this is the most southern occurrence of them.”

Well-preserved fossil offers no clues to adult reptile’s cause of death
While the Texas fossil is well-preserved, how the reptile died remains a mystery since only the snout was found.

It probably died in the water or washed out into the open sea, where it floated to the bottom and was buried very quickly, said Adams. The discovery of seven Terminonaris fossil specimens worldwide is significant, he said.

“To be fossilized, it requires they die at the right time in the right place, be buried very quickly, then eventually be exposed and uncovered,” he said. “So the odds of being fossilized and being found as a fossil are very slim.”

Condon found one piece at the water’s edge of Lake Lewisville. The other pieces were further up a bank that sloped toward the shore, Condon said. The pieces had been deposited on the ground by receding water, pulled from the Woodbine Formation by constant waves that had washed away a soil bank and uncovered the heavy fossils. The outcrop of the Woodbine Formation visible at Lake Lewisville starts at the Red River in North Texas and thins as it nears Dallas.

Condon, who had previously found other fossils in the area, initially thought the pieces were petrified wood.

“This piece looked like a loaf of bread from Subway. It was all wrinkled,” Condon said. “Then I picked it up and turned it over and saw it had teeth — big, round conical teeth — and I thought, ‘This is amazing. It’s a jaw.'”

Co-authors on the article were SMU paleontologists Michael J. Polcyn, Dale A. Winkler and Louis L. Jacobs, and also paleontologist Octavio Mateus, Universidade Nova de Lisboa, Portugal.

The research was funded by Southern Methodist University???s Institute for the Study of Earth & Man. — Margaret Allen

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Tiny teeth discovered from Inner Mongolia are new species of today’s birch mouse, rare “living fossil”

Birch mouse is now 9 million years older than previously known and migrated from Asia to North America

Tiny fossil teeth discovered in Inner Mongolia are a new species of birch mouse, indicating that ancestors of the small rodent are much older than previously reported, according to paleontologist Yuri Kimura, Southern Methodist University in Dallas.

Fossils of the new species were discovered in sediments that are 17 million years old, said Kimura, who identified the new species and named it Sicista primus to include the Latin word for “first.”

Previously the oldest prehistoric ancestor of the modern-day birch mouse was one that inhabited Inner Mongolia 8 million years ago.

Adding 9 million years to the ancestry of the rodent family that includes birch mice and jumping mice distinguishes this genus, Sicista, as a “living fossil,” Kimura said. That places the genus among some of the most unique rodents on earth — those whose ancestry spans 2 to 3 times the average, she said.

Kimura identified Sicista primus from 17 tiny teeth, whose size makes them difficult to find. A single molar is about the size of half a grain of rice. The teeth, however, are distinctive among the various genera of rodents known as Dipodidae. Cusps, valleys, ridges and other distinguishing characteristics on the surface of the teeth are identifiable through a microscope.

“We are very lucky to have these,” Kimura said. “Paleontologists usually look for bones, but a mouse is very tiny and its bones are very thin and fragile. The teeth, however, are preserved by enamel. Interestingly, small mammal teeth are very diverse in terms of their structure, so from that we can identify a species.”

Kimura reported the new species in the article “The earliest record of birch mice from the Early Miocene Nei Mongol, China” in the scientific journal Naturwissenschaften. Images of the research and expedition are posted on the SMU Research flickr site. Go to SMUVideo’s “Inner Mongolia yields ‘living fossil’” to watch Kimura discuss the research.

An SMU doctoral student in the Huffington Department of Earth Sciences, Kimura was part of the international team that discovered the fossils during expeditions to Inner Mongolia in 2004, 2005 and 2007.

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Microscopic evidence of a living fossil
The new fossils of Sicista primus from the Early Miocene age are also now the earliest known record of Sicista, the birch mouse genus that comprises 13 modern and 7 fossil species, said Kimura. As a result, Sicista now boasts the most ancient ancestry of the 326 genera in the largest rodent suborder to which it belongs, Myomorpha. The suborder includes laboratory mice and rats.

“The birch mouse is a rare case of a small mammal genus persisting from the Early Miocene without significant morphological changes,” Kimura said in reporting the findings.

Rodents, both modern and prehistoric, rank as the most prolific mammals on earth. After the reign of dinosaurs, 65 million years ago, rodents evolved and dispersed worldwide during the Cenozoic, the “Age of Mammals.” They comprise about 42 percent of all living mammals. Scientists know now that only 1.5 percent of modern rodent genera, however, go as far back as the Early Miocene or older.

“Diversity within a rodent genus is not unusual, but the long record of the genus Sicista, first recognized at 17 million years ago, is unusual,” said Kimura. “The discovery of Early Miocene S. primus reveals that Sicista is fundamental to understanding how a long-lived genus persisted among substantially fast-evolving rodent groups.”

Birch mice migrated from Asia to North America
Previously the record for the oldest species of Sicista belonged to an 8 million-year-old species identified in Eurasia, Kimura said.

In identifying the new species, Kimura also reverses the long-held hypothesis that ancestors of birch mice migrated from North America to Asia. That hypothesis has been based on a 14.8 million-year-old specimen from South Dakota, which was identified in 1977 as the separate rodent genus Macrognathomys. Kimura’s analysis, however, concludes that Macrognathomys is actually Sicista. For that reason, she concluded, Sicista first inhabited the forests and grasslands of prehistoric Asia and then dispersed to North America via the Bering Land Bridge, Kimura said.

In a comparison of the molars and premolars from Macrognathomys and Sicista primus, Kimura reported finding 12 shared dental characteristics. In addition, phylogenetic analysis to identify evolutionary relationships indicated that both belong to the same genus, Sicista, she said.

Reconnaissance of earlier Central Asiatic Expedition localities yields small mammals
The teeth of Sicista primus were discovered in fine sediments gathered from Gashunyinadege, a fossil locality in the central region of Inner Mongolia.

Gashunyinadege is one of several fossil localities near Tunggur, a fossil site discovered in the 1920s by the Central Asiatic Expedition, which was led by Roy Chapman Andrews from the American Museum of Natural History.

Kimura is a member of an international scientific team sponsored by the Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology and the Natural History Museum of Los Angeles County. The team’s expeditions have been led by paleontologists Qiu Zhuding, IVPP; Wang Xiaoming, Natural History Museum of Los Angeles County; and Li Qiang, IVPP. Their expeditions retrace important classic localities, as well as prospect new fossil localities.

Kimura and other members of the team discovered the birch mouse fossils by first prospecting Gashunyinadege for small mammal fossils visible to the naked eye. Those fossils indicated the possibility of even smaller mammal fossils, so the team gathered 6,000 kilograms, more than 13,000 pounds, of Early Miocene sediment. Using standing water from recent rains, they washed the sediments repeatedly through continually smaller screens to separate out small fossils. Bags of concentrate containing particles the size of mouse teeth were returned to IVPP laboratories to hunt for fossils with a microscope.

The research was funded by the Institute for the Study of Earth and Man at SMU, Dallas Paleontological Society, Geological Society of America, Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology. — Margaret Allen

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with SMU’s Yuri Kimura or to book her in the SMU studio, call SMU News & Communications at 214-768-7650.

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3-D mapping of Guatemala’s “Head of Stone” confirms ancient Maya buildings buried beneath forest cover

Mapping of Maya’s “Holtun” site in Central Lakes region of Guatemala locates triadic pyramid, astronomical observatory, ritual ball court, residential mounds, plazas

Archaeologists have made the first three-dimensional topographical map of ancient monumental buildings long buried under centuries of jungle at the Maya site “Head of Stone” in Guatemala.

The map puts into 3-D perspective the location and size of Head of Stone’s many buildings and architectural patterns, which are typical of Maya sites: 70-foot-tall “triadic pyramid,” an astronomical observatory, a ritual ball court, numerous plazas and also residential mounds that would have been the homes of elites and commoners, according to archaeologist Brigitte Kovacevich, Southern Methodist University, Dallas.

The map situates the primary buildings relative to one another and also places them within the context of the site’s hills and valleys in the Central Lakes agricultural region of north-central Guatemala.

The buildings date from 800 B.C. to 900 A.D., says Kovacevich, an expert in Meso-American cultures and co-leader of an international scientific team that has been granted permission by the Guatemalan government to work the site, which has never before been excavated.

Movement to understand early periods, how kingship developed
Known for its far-reaching state-level government, Maya civilization during the “Classic” period from 200 A.D. to 900 A.D. consisted of huge monumental cities with tens of thousands of people ruled by powerful kings, palaces, pyramidal temples and complex political and economic alliances, Kovacevich says.

The ancient culture at its peak during the Classic period has been well-documented by archaeologists studying the civilization’s large urban centers, such as Tikal, which was one of the most powerful and long-lasting of the Maya kingdoms.

In contrast, “Head of Stone,” called “Holtun” in Maya, is a modest site from the “Pre-Classic” period, 600 B.C. to 250 A.D., she says. The small city had no more than 2,000 people at its peak. Situated about 35 kilometers south of Tikal, “Head of Stone” in its heyday preceded the celebrated vast city-states and kingship culture for which the Maya are known.

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To book a live or taped interview with Dr. Brigitte Kovacevich in the SMU News Broadcast Studio call SMU News at 214-768-7650 or email SMU News at news@smu.edu.

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By excavating a small city, Kovacevich says, the archaeologists hope to understand early Maya trade routes and alliances, the importance of ritual for developing political power, how political power emerged, and how kingship lines evolved and solidified.

“There is a movement toward a greater understanding of these early periods, with smaller sites and common people,” says Kovacevich, an assistant professor in SMU’s Anthropology Department. “Little is known about how kingship developed, how individuals grabbed political power within the society, how the state-level society evolved and why it then was followed by a mini-collapse between 100 A.D. and 250 A.D.”

Kovacevich presented “‘Head of Stone’: Archaeological Investigation at the Maya Site of Holtun, Guatemala” during the 76th annual meeting of the Society for American Archaeology in Sacramento, Calif., March 30 to April 3.

Besides Kovacevich, archaeologists on the team and co-authors of the paper are Michael G. Callaghan, University of Texas at Arlington; Patricia R. Castillo, Universidad San Carlos, Guatemala; and Rodrigo Guzman, Universidad del Valle, Guatemala. The 3-D topographic map expands surveys from 1995 and 2002 by Guatemalan archaeologist Vilma Fialko and Guatemala’s Institute of Anthropology and History, which were documented by Fialko and archaeologist Erick M. Ponciano.

Situated in a patch of rainforest on defensible escarpment
Head of Stone today sits in a patch of rainforest surrounded by cow pastures and cornfields on a limestone escarpment, which would have made it highly defensible, Kovacevich says.

Holtun’s structures — more than 100 of them — now are overgrown with a thin layer of centuries-old jungle foliage and soil. The site is about one kilometer long and half a kilometer wide, or almost three-quarters of a mile long and one-third of a mile wide. The large mounds protruding here and there from the jungle floor signal to archaeologists the familiar building arrangements customary at a Maya site, Kovacevich says.

As with most Maya sites, looters have tunneled into many of the important structures. Kovacevich and her colleagues will dig more tunnels to further explore the buildings with the help of Guatemalan experts skilled at working Maya sites.

Key structures: “E Group,” residential group
The 3-D mapping has confirmed an “E Group,” a key Maya architectural structure. Holtun’s “E Group” dates from 600 B.C. to 600 A.D. and consists of stair-step pyramids and elongated buildings that likely served as astronomical observatories central to Maya rituals. A stepped pyramid to the west of a long narrow building directly oriented north-south served as the observational structure and was related to veneration of sacred ancestors, Kovacevich says.

“From the observational structure you can see the sun rising at the different solstices throughout the year, which is very important agriculturally, to know the timing of the seasons and when to plant and when to harvest,” she says. “So the people creating this are harnessing that knowledge to show their followers and constituents that they possibly are even controlling the change of seasons.”

Adjacent to the “E Group” are four structures that face one another around a central patio. The pattern usually indicates a residential group, where cooking and food processing were carried out on the patio, Kovacevich says.

“The closeness of the residential structure to the “E Group” suggests these were very early elites, and possibly kings,” she says. “Kingship was just being established during this period.”

The Maya often left offerings to their ancestors, such as jade or ceramics, at the base of structures.

Triadic pyramid represents Maya mythology?
Besides the “E Group,” a triadic pyramid dating from 300 B.C. to 300 A.D. sits at the north end of the site. As is typical at Maya sites, three pyramids about 10 feet tall sit atop a high platform that rises about 60 feet from the jungle floor, Kovacevich says. One of the pyramids faces south, flanked on either side by the other two, which face inward around a central patio. The platform sits atop — and obscures — an earlier sub-structure platform, buried underground and decorated with monumental masks that are visible from the looters’ tunnels.

“Some archaeologists argue that this configuration represents elements of Maya mythology: the three hearthstones of creation that were set down by the gods to create the first home and hearth, thereby civilizing humanity,” Kovacevich says. “Re-creation of that by the people at Holtun would show piousness and connection to ancestors.”

During the Classic period, kings were typically buried in Maya pyramids. During the Pre-Classic period, however, that isn’t the case and they were typically buried in their residence. It’s possible an early king of Holtun was buried in one of the residential structures, Kovacevich says.

“Ancestors are buried beneath the floor and kept very close and venerated,” she says. “The more ancestors a residence has, the more times the family redoes their floor, making a new floor, and so their mound gets higher and higher. A person with more ties, more ancestors, has more status.”

Another familiar structure is a ball court, signified by two long mounds that are exactly parallel, said Kovacevich.

“Those are the two sides of the ball court, and the ball would have been bounced in the center off of the sides,” she said. “Almost all Maya sites had a ball court.”

The team’s Holtun excavation is scheduled to start this summer. Funding is from the Institute for the Study of Earth and Man, the Downey Family Fund for Faculty Excellence and SMU. — Margaret Allen

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility on campus for live TV, radio or online interviews. To speak with Dr. Kovacevich or to book her in the SMU studio, call SMU News & Communications at 214-768-7650.

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Modern-day bamboo tool-making shines light on scarcity of Stone Age tools from prehistoric East Asia

Bamboo knives are easy to make — and will cut meat, but not hides, suggesting prehistoric people preferred crudely made stone flakes

The long-held theory that early human ancestors in East Asia crafted their tools from bamboo and wood is much more complicated than originally conceived, according to a new study.

Research until now has failed to address a fundamental question: Is it even possible to make complex bamboo tools with simple stone tools?

Now an experimental archaeological study — in which a modern-day flint knapper replicated the crafting of bamboo knives — confirms that it is possible to make a variety of bamboo tools with the simplest stone tools.

However, rather than confirming the long-held “bamboo hypothesis,” the new research shows there’s more to the theory, says archaeologist Metin I. Eren, the expert knapper who crafted the tools for the study.

Study: Bamboo knives were efficiently crafted and able to cut meat, but not hide

The researchers found that crudely knapped stone choppers made from round rock “cobbles” performed remarkably well for chopping down bamboo. In addition, bamboo knives were efficiently crafted with stone tools.

While the knives easily cut meat, they weren’t effective at cutting animal hides, however, possibly discouraging their use during the Stone Age, say the authors. Some knives made from a softer bamboo species entirely failed to produce and hold a sharp edge.

“The ‘bamboo hypothesis’ has been around for quite awhile, but was always represented simply, as if all bamboo species, and bamboo tool-making were equal,” says Eren, a doctoral candidate in anthropology at Southern Methodist University in Dallas. “Our research does not debunk the idea that prehistoric people could have made and used bamboo implements, but instead suggests that upon arriving in East and Southeast Asia they probably did not suddenly start churning out all of their tools on bamboo raw materials either.”

The findings appear online in the article “Were Bamboo Tools Made in Prehistoric Southeast Asia? An Experimental View from South China,” which will be published in an issue of the journal Quaternary International, edited by Parth Chauhan and Rajeev Parnaik.

“The importance of experimental archaeology, of replicating the production of bamboo tools with simple stone artifacts, was needed for a long time. Due to successful cooperation in every stage of the experiments with our Chinese colleagues, we managed to demonstrate the potential of a simple stone tool technology to produce many different daily tools made of bamboo,” said archaeologist and lead author Ofer Bar-Yosef, professor of Stone Age archaeology at Harvard University.

In addition to Bar-Yosef and Eren, co-authors were archaeologists Jiarong Yuan and Yiyuan Li of Hunan Provincial Institute of Archaeology and Cultural Relics; and archaeologist David J. Cohen of Boston University.

Poor diversity of prehistoric stone tools in Southeast Asia
As in Africa, previous fossil discoveries in East Asia have indicated that early human ancestors continuously inhabited those regions for as much as 1.6 million years. Unlike Africa and western Eurasia, however, where stone tools show increasing and decreasing complexity, East Asia’s stone tools remain relatively simple.

Researchers know that simple flaked “cobble” industries existed in some parts of the vast East and Southeast Asia region, which includes present-day China, Brunei, Cambodia, Indonesia, Laos, parts of Malaysia, Myanmar, Philippines, Thailand, East Timor and Vietnam. Stone tool discoveries there have been limited to a few hand axes, cleavers and choppers flaked on one side, however, indicating a lack of more advanced stone tool-making processes, innovation and diversity found elsewhere, say the authors.

The lack of complex prehistoric stone tool technologies has remained a mystery. Some researchers have concluded that prehistoric people in East Asia must have instead crafted and used tools made of bamboo — a resource that was readily available to them.

Scientists suggest several reasons for missing stone tool industry
Scientists have hypothesized various explanations for the lack of complex stone tools in East and Southeast Asia. On one hand, it’s been suggested that human ancestors during the early Stone Age left Africa with rudimentary tools and were then cut-off culturally once they reached East Asia, creating a cultural backwater.

Others have suggested a lack of appropriate stone raw materials in East and Southeast Asia. In the new study, however, Bar-Yosef, Eren and colleagues showed otherwise by demonstrating that more complex stone tools could be manufactured on stone perceived to be “poor” in quality.

Studies set out to test “bamboo theory” by replicating stone tools
Prolific in East and Southeast Asia, bamboo stands grow fast and thick, reaching maturity in 5 to 7 years and totaling more than 1,000 species, the authors say.

In a 2007 pilot study and a 2008 expanded study the authors worked with the Archaeological Field Research Station of the Hunan Provincial Institute of Archaeology and Cultural Relics in Shimen, China. Experiments were carried out in three locations across Hunan province known to possess clusters of Paleolithic sites.

The researchers gathered different kinds of cobble-sized rocks along the banks of the Li, Wu and Xiao Shui rivers, similar to those that would have been available to prehistoric human ancestors.

From those rocks, Eren easily replicated flake tools and stone choppers, some of them flaked on one side and some flaked on two sides. The team then observed a local bamboo toolmaker — who used metal tools to easily slice the bamboo — to learn techniques for sawing, shaving, splitting, peeling and chopping bamboo.

Stone tools efficiently chopped down bamboo stalks and produced knives
Using the crudely knapped stone choppers, the researchers in 84 minutes chopped down 14 bamboo stalks representing five species. When cut, the stalks, both small and large in diameter, totaled more than 65 meters in length. The stone tools performed remarkably well for that purpose, the authors write. That was especially true, they said, considering the tools were wielded by two modern people who were inexperienced with chopping bamboo, researchers Eren and Li. But Eren sometimes found himself scrambling up trees to release felled bamboo wedged in branches.

After numerous trials, the researchers developed a simple “bamboo knife reduction sequence” that could produce 20 sharp, durable bamboo knives in about five hours. Using pork purchased from a local market, the researchers write, they found that the knives easily cut meat, but not hide.

In other findings, the authors write that with a simple stone unifacial chopper, Bar-Yosef was able in 30 minutes to easily make a sharp spear that would have been capable of killing an animal. Also, using the replicated stone tools they were able to produce strips of bamboo thin enough for weaving baskets. “For some items, like baskets, bamboo might have been an ideal raw material,” Eren said.

“But one is left to wonder, at least for butchery tasks, why a prehistoric person would go to the trouble of producing a bamboo knife when a stone flake would certainly do the trick,” the authors write.

Unprecedented study confronts long-standing assumption
“The so-called bamboo hypothesis, to explain the virtual absence of complex prehistoric stone tool technologies in eastern and southeastern Asia, has been often cited but always remained somewhat ambiguous,” said Chauhan, co-editor of the Quaternary International issue in which the article will be published. “This unprecedented experimental study by Ofer Bar-Yosef, Metin Eren and colleagues represents a first step in the right direction, to confront a long-standing assumption about early human technological adaptations.”

Funding for the research was provided by the American School of Prehistoric Research, Harvard University; a National Science Foundation Graduate Research Fellowship; and the Department of Anthropology, Southern Methodist University.

SMU is a private university in Dallas where nearly 11,000 students benefit from the national opportunities and international reach of SMU’s seven degree-granting schools. For more information see www.smuresearch.com. Follow SMU Research on Twitter, @smuresearch.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with Metin Eren or book him in the studio, call SMU News & Communications at 214-768-7650.

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Flying Texas reptile: World’s oldest Pteranodon? First specimen of its kind discovered as far south as Texas

Unique specimen is first of its kind discovered as far south as Texas, where it flew over a vast ancient sea

Fossilized bones discovered in Texas from a flying reptile that died 89 million years ago may be the earliest occurrence of the prehistoric creature known as Pteranodon.

Previously, Pteranodon bones have been found in Kansas, South Dakota and Wyoming in the Niobrara and Pierre geological formations. This likely Pteranodon specimen is the first of its kind found in Texas, according to paleontologist Timothy S. Myers at Southern Methodist University in Dallas, who identified the reptile. The specimen was discovered north of Dallas by an amateur fossil hunter who found various bones belonging to the left wing.

Pteranodon was a type of pterosaur that lived about the same time as some dinosaurs, about 100 million to 65 million years ago. The only reptiles to dominate the ancient skies, pterosaurs had broad leathery wings and slim torsos.

Adult pterosaur, toothless variety with about a 12-foot wing span
The specimen identified by Myers is an adult pterosaur of the toothless variety and while larger than most birds, wasn’t among the largest pterosaurs, Myers said, noting it had a wing span between 12 and 13 feet, or 3.6 to 4 meters. It was discovered in the Austin Group, a prominent rock unit in Texas that was deposited around 89 million years ago, early in the geological time period called the Late Cretaceous.

Pterosaurs, many of which survived on fish, lived at a time when a massive ancient sea cut across the central United States. The Western Interior Seaway was a shallow body of water that split North America in half from the Arctic Ocean to the Gulf of Mexico.

More than a thousand Pteranodon fossils have been unearthed from the middle part of the seaway.

No definitive Pteranodon specimens have emerged from the southern part that is now Texas.

The SMU specimen, if it is Pteranodon, would be the first discovered so far south in the Western Interior Seaway, said Myers, a postdoctoral researcher in SMU’s Huffington Department of Earth Sciences.

Myers reported and described the specimen in “Earliest Occurrence of the Pteranodontidae (Archosauria: Pterosauria) in North America; New Material from the Austin Group of Texas” in the Journal of Paleontology.

Left wing suggests Pteranodon; cause of death a mystery
Key to identifying the SMU fossils as Pteranodon is a humerus of 5.7 inches, or 14.5 centimeters. The humerus is the uppermost bone in the wing and attaches to the torso. The humerus of the SMU specimen, while complete, did suffer some damage during fossilization when it became compressed and distorted through millions of years of compaction.

“If it wasn’t crushed so badly, it would be possible to determine if it really is Pteranodon,” Myers said. “These bones are easily flattened. They are hollow inside, because they have to be lightweight to allow a pterosaur to fly. So they compress like a pancake as they’re embedded in layers of rock.”

While it’s difficult to narrow the humerus definitively to a specific genus and species, some features clearly identify the specimen as part of the Pteranodontidae family, most likely the genus Pteranodon. It exhibits, for example, the prominent warped deltopectoral crest that is characteristic of members of the Pteranodontidae family, called pteranodontids, he said.

Discovered along with the humerus were parts of the elongated fourth finger that in pterosaurs forms the wing. The SMU specimen’s metacarpal — at 20 centimeters — is incomplete, missing an estimated 37 percent of its length.

The fossils do not solve the mystery of the reptile’s cause of death, Myers said. But it appears the animal probably died in flight over the sea and then fell into the water. Its carcass probably floated for some time, so that when the flesh decomposed the bones separated at the joints, known as “disarticulation,” before they settled to the sea floor and were buried.

“We know it was disarticulated when it was buried because the bones weren’t preserved in correct anatomical position,” Myers said. “Abrupt truncation of the broken end of one of the bones and infilling of the break with sediment also indicates that the breakage and disarticulation took place prior to burial.”

May be oldest Pteranodon in world
If the specimen represents Pteranodon, Myers said, it would be the oldest one in North America by 1 million to 2 million years, and the second oldest pteranodontid in the world.

Pterosaurs were alive from the Late Triassic — more than 200 million years ago — to the Late Cretaceous, evolving from small-bodied creatures to some of the largest animals to ever inhabit the skies, Myers said. An older pteranodontid specimen, belonging to the genus Ornithostoma, previously was identified in England.

“Any pterosaur material is fairly rare to find unless you have exceptional preservation conditions. They are frail, fragile bones, and they require rapid burial to be well preserved,” Myers said. “The SMU specimen was deposited relatively far offshore in deep water, perhaps 50 to 80 feet deep. It’s fairly exceptional because of the number of elements. Typically you’ll only find one piece, or one part of a piece in the local rock.”

During the Early Cretaceous, many types of pterosaurs lived around the world, Myers said. The earliest ones had thin, razor-sharp teeth. In the transition from Early to Late Cretaceous, the toothed variety disappear from the fossil record and toothless forms, like the SMU specimen, become more common, he said.

Dallas area specimens illustrate pterosaur evolution
North Texas is fortunate to have had both the toothed and toothless kinds discovered in the area, illustrating the evolutionary transition, noted Myers.

Besides the toothless specimen just identified by Myers, an older toothed pterosaur, Aetodactylus halli, previously was discovered in the Dallas area. Aetodactylus, also identified by Myers, lived 95 million years ago.

“This new specimen adds a lot more information about pterosaurs in North America,” Myers said. “It helps constrain the timing of the transition from toothed to toothless because there’s only a few million years separating this specimen and Aetodactylus.”

Amateur fossil collector Gary Byrd of Rockwall, Texas, discovered the new SMU pterosaur fossils about 10 years ago.

A roofing contractor who keeps an eye out for fossils, Byrd made the find after stopping to look at two freshly excavated culverts while driving through a new subdivision in Collin County. Using a hammer and pick he dug out the bones and brought them to SMU paleontologists Louis Jacobs and Dale Winkler. Jacobs and Winkler indicated the fossils were likely a pterosaur. Byrd donated the fossils to SMU’s Shuler Museum of Paleontology.

“I found a couple parts of a fish, and then when I saw these my initial thought was that they weren’t fish,” Byrd recalled. “I kind of knew it was something different — a birdlike thing. It’s very rare you find those thin, long bones.”

This isn’t the first time Byrd has hit it lucky finding fossils. In 1994 he discovered dinosaur bones that he donated to SMU’s Shuler Museum. The specimen was identified as a rare primitive duck-billed dinosaur and named Protohadros byrdi after Byrd. — Margaret Allen

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