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Tuesday, May 28, 2013

New Feathered Dinosaur Discovered in Texas' Big Bend National Park

Like Darwin's many finches living side-by-side in the Galapagos Islands, a surprising variety of feathered, bird-like dinosaurs once roamed the ancient West from Alberta to Texas, scientists say.

A team of paleontologists at Yale University, led by Dr. Nick Longrich, says it has identified a whole new genus of dinos from fossils found in and around Texas' Big Bend National Park. And their analysis suggests that the diversity of dinosaurs both there and elsewhere was probably much richer than we ever thought.
Leptorynchos gaddisi, a newly identified dinosaur species, lived in Texas about 75 million years ago and was about the size of a dog. ©2013 Nick Longrich
"In general it appears that dinosaur species are pretty localized -- this is one more piece of evidence supporting that," Longrich told Western Digs. "But fossils of duckbills and ceratopsids [found elsewhere] tell the same story."

The new genus, named Leptorynchos or "small beak," is a type of caenagnathid -- a toothless, bird-like dinosaur about the size of a dog that lived some 75 million years ago. And it includes a newly identified species, Leptorynchos gaddisi, distinguished by the genus' eponymous short, blunt beak.

Scientists found clues of the new group while studying fossils excavated from an old WPA rock quarry in Big Bend National Park, and from a site in the nearby town of Terlingua, just outside the park boundary.

Big Bend National Park (NPS)
While other, very similar species had been found in the park -- and throughout the West from New Mexico to Alberta -- Longrich's team was struck by the difference in the beaks of the new Texas specimen.

As the researchers point out in their paper, just published in the Bulletin of the Peabody Museum of Natural History, beaks are a key to differentiating species among living dinosaurs -- that is, birds -- so the same should be true for extinct dinosaurs.

In this case, L. gaddisi had a narrower beak that was less upturned than in similar caenagnathids. Indeed, it was much like that of modern tortoises and parrots, suggesting that its diet was largely, maybe exclusively, herbivorous.

What's more, the dino's telltale beak was especially well adapted for tearing through tough, fibrous plants, while other related dinosaurs likely went for softer fare.

This strengthens the case that the region once hosted a great diversity of dinosaurs, the team says, because it suggests that -- much like Darwin's finches -- similar animals living in close quarters diverged into separate species over time, so as not to compete for the same resources.

For this reason, Longrich says, the small new dinosaur could have big consequences, and possibly bring controversy.

"I think the important thing it tells us is that dinosaurs were really, really diverse, and we haven't even begun to scratch the surface in terms of the number of species," he said.

"There are some people out there who say we have too many dinosaur species … and they're just wrong."

 Sources:

• Bulletin of the Peabody Museum of Natural History, Yale University, Volume 54, Issue 1

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