Coelophysis

Coelophysis was an agile, slender early theropod that flourished throughout southwestern North America during the Late Triassic. It grew to roughly three metres in total length but had hollow, thin-walled bones that kept its body mass exceptionally light, around twenty kilograms. At the famous Ghost Ranch quarry in New Mexico, hundreds of complete skeletons were buried together in a flash flood event, providing an unprecedented view of its anatomy, growth rates, and distinct robust and gracile morphs. Its long, flexible neck supported a narrow head lined with finely serrated teeth, perfect for catching small reptiles, cynodonts, and fish. Although bones discovered within the abdominal cavity of one individual were originally thought to indicate cannibalism, restudy revealed them to be the remains of small crocodylomorphs. Coelophysis remains one of the best-understood early predatory dinosaurs in the fossil record.

Hundreds of complete skeletons were unearthed together at Ghost Ranch in New Mexico.

Where and when

Coelophysis lived in the Late Triassic, from 216 to 201 million years ago (Norian-Rhaetian age). Its remains come from United States, in the Chinle Formation.

The numbers

Length 2.9 m (estimates run from 2.7 to 3 m). Mass about 19 kg. Hip height about 0.8 m. That is 1.7 human-lengths, or 0.26 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Coelophysis with a bus Place on the timeline