New Look Suggests This Dinosaur Is No Beast
Monday, October 2, 2006
Alas, poor Coelophysis! We thought we knew him well.
Prehistoric inhabitant of New Mexico.
And above all, a cannibal. So heartless, so cold, it ate its own young.
Or so the story went.
Now a new analysis of the fossil evidence indicates that scientists did not know Coelophysis (pronounced SEE-lo-FYE-sis) so well after all. Bones preserved inside the fossilized stomach of an adult Coelophysis, long believed to be the remnants of a snack-sized baby Coelophysis and the primary evidence for cannibalism by that species, are actually bones from a crocodile of sorts -- the kind of prey that even the most ethically demanding paleontologist would find perfectly acceptable.
The rehabilitation of Coelophysis's reputation is a reminder of the difficulty of inferring animal behaviors from bits of bony evidence. But as museums prepare to revamp their displays -- and as publishers mull culling those loveable images of dino parents eating their own kids -- it is also a reminder that science means never having to say you're sorry.
"In science, all ideas must be open for testing," said Sterling Nesbitt, the PhD student at Columbia University who led the research that debunked the decades-old presumptions about Coelophysis.
The story begins in 1947, when scientists from New York's American Museum of Natural History excavated a remarkable bed of prehistoric bones containing more than 1,000 skeletons of Coelophysis bauri , one of the earliest dinosaurs to walk the Earth.
The largely intact skeletons, up to nine feet long from tail tip to nose, were in many cases stacked atop one another. Scientists suspect a huge herd was wiped out in a flash flood and quickly buried in mud and sand.
From this treasure trove of bones, two specimens in particular have taken on mythic lives of their own. Both were skeletons of Coelophysis adults that appeared to have remains of young Coelophysis in their stomachs. Over time, those specimens gained reputations as bedrock proof that this species fed on its own young.
"Pick up any dinosaur book, a children's book or textbook or even the primary scientific literature, they continually point to this as evidence of cannibalism," said Mark Norell, curator of the American Museum of Natural History. "Wherever Coelophysis is on display, there is some allusion to its being a cannibal."