Coelophysis is a very well known early dinosaur as scientists have discovered hundreds of skeletons of this meat-eater. It is the oldest dinosaur known in North America, living around 216 to 203 million years ago, during the Late Triassic Period. It was a swift hunter that seemed to eat almost anything it could catch. Some of the skeletons found in New Mexico had the remains of what appeared to be smaller Coelophysis in their stomachs, suggesting it occasionally resorted to cannibalism. It wasn't until in 2002 that the remains from the Ghost Ranch specimens have been re-examined, and later concluded that the "juvenile coelophysids" found in the abdominal cavities were actually from small crurotarsan reptiles such as Hesperosuchus. This is likely the result of the fossil of a larger individual overlapping a smaller one.
Coelophysis could get fairly large for an early dinosaur, with adults ranging to a size of up to 3 m (10 feet). These sizes are generally divided into two specimen types - robust and gracile - and are thought to represent gender differentiation. Being a basal (one of the first) theropods, it had some characteristics which were lost on later members of the theropod family. It still had four fingers, although the fourth digit was quite small.
The remains of hundreds of individuals were found at Ghost Ranch in New Mexico, which provided scientists with an unprecedented opportunity to study the individual differences within a large herd of the same dinosaurs.
Like other early carnivores, Coelophysis had many small, sharp teeth. As is shown by the vast numbers of individuals at Ghost Ranch, it is evident that early dinosaurs exhibited social behavior to the extent of congregating in large packs. The exact purpose of this large gathering is not known, but some scientists feel that it may have been breeding season.
Coelophysis is at the base of the family tree of a great many dinosaurs including all the dilophosaurs, oviraptors, ornithomimids and the ever popular "Raptor" family which includes Velociraptor, Utahraptor, and Deinonychus.
Note that the original type material, which may or may not belong to the same kind of animal as those later found at Ghost Ranch, has been given its own (disputed) genus: Eucoelophysis ("true Coelophysis").
A Coelophysis skull became the first dinosaur fossil to be taken into space in January 1998 when the Space Shuttle "Endeavor" carried a specimen from the Carnegie Museum to the Mir Space Station.
Coelophysis was featured in the Game Boy Advanced game Jurassic Park III: Park Builder.
A display featuring Coelophysis (or at least its figure from the Dino theme from 2012) is seen on the top floor of the Innovation Center in the level "Main Street Showdown". This display must be destroyed in order to advance in the level.
Coelophysis appeared in Jurassic Park Series 1 toy line, it came with constrictor bodies and comes with 2.