Eucoelophysis

true Coelophysis ("true hollow form")

• eu · Greek · true, good
• koilos · Greek · hollow
• physis · Greek · form, nature

The name combines the Greek "eu" (true or good) with Coelophysis, the name of another Triassic reptile from New Mexico. It was chosen because the original describers thought the fossils belonged to a true coelophysoid, a close relative of Coelophysis. That identification was later revised, so the name now reflects a mistaken early classification.

Named by

Sullivan and Lucas

Year named

1999

Period

Late Triassic

Stage

Norian

Found in

Petrified Forest Member, Chinle Formation, New Mexico, USA

The type species is Eucoelophysis baldwini. It was first described as a coelophysoid theropod dinosaur. Later work (Ezcurra 2006, Nesbitt et al. 2007) showed that the remains belong to a silesaurid, a dinosauriform close to the origin of dinosaurs. Some of the material first assigned to it may be a chimera. Whether it counts as a true dinosaur depends on how Silesauridae is classified, and most recent studies place silesaurids just outside Dinosauria.