Coelophysis was one of the first dinosaurs that we know about. It lived about 210 million years ago. Coelophysis was a very primitive or simple dinosaur. It was small, about nine or ten feet long, and walked on two legs. It had a long, curved neck and a pointed head. From the dinosaur’s teeth, we can see that it was probably a carnivore, meaning that it ate meat. Coelophysis had many small teeth that were sharp and serrated like a saw. It was probably a fast runner, judging from footprints of this dinosaur. These footprints are called “trackways”. When the trackways are far apart, we can see that the dinosaur took big steps when it was running.
Coelophysis was a theropod dinosaur, meaning that it ate meat and ran on two legs. While most theropods had three fingers on each hand, this creature had four. It also had light, hollow bones, which is where it gets its name: Coelophysis means “hollow form”. It lived in dry, desert-like places. It ate small reptiles, fish, and even smaller dinosaurs. Like all the other dinosaurs, Coelophysis laid eggs.
Coelophysis hunted in groups. We know this because of the fossils we have found. In 1947, more than 100 Coelophysis skeletons were found in one valley in what is now New Mexico. No one knows why so many of them died at the same time. An entire herd or group might have died in a flood or an earthquake. But we do know that they lived in large groups and hunted together. Coelophysis bones have been found mostly in what is now the southwestern United States.