for National Geographic News
It's not easy rescuing a reputation that's been trashed, especially if the subject has been dead for more than 200 million years. But that's what Robert Gay, a paleontology student at Northern Arizona University, is trying to do for a dinosaur with a rep as a cannibal.
Coelophysis (SEE-loh-FIE-sis) was a small, fast, meat-eating predator that lived in western North America during the Late Triassic (roughly 228 to 208 million years ago). A huge bone bed at Ghost Ranch, New Mexico, has hundreds, if not thousands of Coelophysis skeletons, representing all age groups.
"There is no other dinosaur in the world for which we have as many skeletons," said Hans-Dieter Sues, curator of vertebrate paleontology and associate director for science and collections at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.
Yet this spectacularly abundant fossil assemblage presents paleontologists with as many questions as answers.
Was Coelophysis a cannibal? Did they hunt in packs? Why were so many in one place at the same time? How did they die? Where did they die?
It's a Hard, Cruel World
These early dinosaurs had bodies the size of turkeys, but with long legs, long tails, and long necks. The neck and tail accounted for most of its 6-to-7-foot (2-meter) length. Coelophysis had hollow bones, was bipedal, and weighed 50 pounds (around 20 kilograms).
"It was extremely agile and nimble, and must have been a really fast little bugger, it was built so light," said Michael Williams, curator of vertebrate paleontology at the Cleveland Museum of Natural History.
The Ghost Ranch bone quarry was first excavated in 1947 under the direction of Edwin H. Colbert, a paleontologist with the American Museum of Natural History. Colbert published a scientific description of the animal in 1989. In it, he described two adults with the skeletons of young Coelophysis in their rib cages. The juvenile skeletons were too large and well developed to be unborn babies. This led him to conclude that Coelophysis was a cannibal.
Gay, in a presentation at the 62nd Annual Meeting of the Society of Vertebrate Paleontology this past October, argued that Coelophysis had been maligned. He contended that the larger animals were merely lying on top of the younger ones.
There is a precedent for revising a dinosaur's reputation. Oviraptor fossils were first found near nests, giving them their name, which literally means "egg stealer." Later finds revealed that they were sitting on their own nestshatching, not eating the eggs.
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