Temporal range: Late Triassic – Early Jurassic
|An artist's illustration of Coelophysis bauri|
| †Coelophysis bauri|
Coelophysis (see - low - FI - sis) 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.
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 herds. 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.
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. With this discovery and to date, Coelophysis would no longer be recognized for having a cannibalistic behavior.
Appearance in Media
In the first episode of Walking with Dinosaurs, it is shown hunting lungfish, cynodonts and eating a dying Postosuchus as well as each other during a drought. It also appeared in When Dinosaurs Roamed America.