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Bizarre Species

domingo, 2 de mayo de 2010

Toothy Texas Pterosaur Discovered; Soared Over Dallas


Long before six flags flew over Texas, a newfound species of winged reptile with an exceptionally toothy grin owned the skies over what is now the Lone Star State.

The recently discovered pterosaur, dubbed Aetodactylus halli, was identified based on a 95-million-year-old lower jawbone found outside of Dallas by amateur fossil hunter Lance Hall. The pterosaur had a relatively slender jaw filled with thin, needlelike teeth, which might have helped the creature pluck fish from the shallow sea that once covered the region, a new study says.

"It was hanging out near the ocean, and that is probably where it derived its food from," said study leader Timothy Myers, a paleontologist at Southern Methodist University in Dallas.

By comparing the jawbone to more complete pterosaur fossils, Myers and his team think A. halli was a medium-size animal with a nine-foot (three-meter) wingspan and a short tail.

Texas's Toothy Pterosaur a Rare Find

Pterosaurs ruled the skies from the late Triassic period, more than 200 million years ago, until dinosaurs went extinct at the end of the Cretaceous, about 65 million years ago.

At 95 million years old, A. halli is one of the youngest members yet found in the Ornithocheiridae family of toothed pterosaurs, Myers said.

Despite being common elsewhere in the world, toothed pterosaur fossils are rare in Texas: A. halli is only the second ornithoceirid yet discovered in North America.

The new pterosaur had 54 teeth in its lower jaw, which is an unusual amount for ornithoceirids, Myers added. Most other members of the family had just 30 lower jaw teeth. Only Boreopterus, a relative from the same time period found in China, is known to have had as many teeth as A. halli.

When the animal lived, a giant north-south interior seaway split North America from the Gulf of Mexico to the Arctic Ocean, putting what is now Dallas underwater.

A. halli's jawbone was found in marine rocks exposed near a highway in Mansfield, southwest of Dallas (see map), which would have been the southernmost end of the ancient sea. No other fossils from the animal have been unearthed nearby, Myers said.

"It could be that something caused the pterosaur to die and fall into the water," he said. "Decay started, and the lower jaw just fell off and got separated from the rest of the body."

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