Coelophysis is one of the earliest known dinosaur genera. It was about three metres long and weighed up to 20 kg.

Coelophysis had a long, narrow head with large, forward-facing eyes that gave it good stereoscopic vision. This swift, agile animal probably relied on its vision in hunting its prey, which consisted mainly of smaller vertebrates. The teeth were typical of carnivorous dinosaurs, slightly curved with serrated (jagged or sawlike) edges.