Coelophysis

What it was like

Coelophysis was a small, slender, bipedal predator built for speed, with a long neck, a narrow skull, and rows of sharp, curved teeth. It grew to about 3 meters (10 feet) long, though much of that length was a thin, whip-like tail.

Its bones were thin-walled and lightly built, keeping the animal quick on its feet. Coelophysis probably hunted small animals, and one fossil even preserves bones inside its body cavity that some researchers think are the remains of a meal.

Its world

Coelophysis lived from about 227 to 201 million years ago, in the Late Triassic, in what is now the southwestern United States, with fossils found in New Mexico, Texas, Arizona, and as far away as Connecticut and Massachusetts. Its bones come from formations including Chinle, Petrified Forest, Cooper Canyon, and Dockum.

It lived alongside early dinosaur relatives such as Chindesaurus, Daemonosaurus, and Camposaurus, in a world where dinosaurs were still a small part of the animal community.

How it was found

Cope named Coelophysis in 1889. About 22 fossil finds are known, including one exceptional site where the skeletons of many individuals were found together, among the largest gatherings of a single dinosaur species ever found. Coelophysis is considered one of the earliest known dinosaur genera. The related genus Megapnosaurus was once classified as a species of Coelophysis, though most paleontologists now treat it as separate.