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Journalism of Courage
Alas, poor Coelophysis! We thought we knew him well. Birdlike dinosaur. Prehistoric inhabitant of New Mexico. And above all, a cannibal. So heartless, so cold, it ate its own young.
Or so the story went.
8220;In science, all ideas must be open for testing,8217;8217; said Sterling Nesbitt, PhD student at Columbia University who led the research that debunked the presumptions about Coelophysis.
The story begins in 1947, when scientists from New York8217;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 9 ft 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 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. 8220;Pick up any dinosaur book, a children8217;s book or textbook or even the primary scientific literature, they continually point to this as evidence of cannibalism,8217;8217; said Mark Norell, curator of the American Museum of Natural History.
Then, last year, Nesbitt noticed something peculiar while waiting for the C train in the 81st Street station of the New York City subway system. That8217;s the station for the natural history museum, and its walls are adorned with high-quality bronze castings of fossils8212;including one of the famed Coelophysis cannibal fossils.
8220;I was looking at how well this one was done,8217;8217; said Nesbitt, who at the time was a second-year doctoral student in a paleontology. 8220;It was a very good replica of the actual specimen, which I had not seen up close because it was behind glass8217;8217; in the museum.
Nebitt ran his finger over the casting of the leg bone inside the dinosaur8217;s stomach, trying to feel the slightly offset head of the femur8212;a small knob characteristic of dinosaur bones. For the life of him, he said, he could not feel it. 8220;After that,8217;8217; Nesbitt said, 8220;I told Mark we should definitely reexamine the original because I8217;m pretty sure it8217;s not a dinosaur.8217;8217;
Arrangements were made to have the display8217;s glass removed. Using solvents and fine tools, the researchers removed the key bone from the 210-million-year-old specimen. The verdict was straightforward: That dinosaur8217;s last meal had not been a baby Coelophysis after all8212;indeed, was not any kind of dinosaur8212;but was some other reptile.
That led to a closer examination of the other New Mexico specimen. The bones do appear to be those of Coelophysis. But one is far too large to have been swallowed whole. And the orientation of those supposedly swallowed bones makes it virtually certain that they are from a small individual that was crushed beneath the larger animal when disaster struck.
8220;Our results show that although stomach contents were remarkably preserved 8230; no evidence for cannibalism exists,8217;8217; the team concluded in last week8217;s issue of Biology Letters, a publication of the Royal Society.
8212;LAT-WP / Rick Weiss
