Temporal range: Late Triassic–Early Jurassic
Coelophysis feathers
An artist's illustration of Coelophysis bauri
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Superorder: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Coelophysidae
Subfamily: †Coelophysinae
Genus: Coelophysis
Cope, 1889
Type species
Coelophysis bauri
Cope, 1887
Referred species
  • Coelophysis bauri (Cope, 1887)
  • Coelophysis kayentakatae? (Rowe, 1989)
  • Coelophysis rhodesiensis (Raath, 1969)
  • Podokesaurus? Talbot, 1911
  • Longosaurus Welles, 1984
  • Rioarribasaurus Hunt & Lucas, 1991
  • Megapnosaurus Ivie, Ślipiński & Węgrzynowicz, 2001
  • Gojirasaurus? Carpenter, 1997

Coelophysis (see - low - FI - sis) (Greek meaning "hollow form") was a dinosaur from the Late Triassic Period, living around 202 to 196 million years ago. It is the oldest dinosaur found in North America and scientists have discovered hundreds of skeletons of it.

Coelophysis could get fairly large for an early dinosaur, with adults ranging to a size of up to 3 meters (10 feet) and 1 meter (3 feet) tall. These sizes are generally divided into two specimen types - robust andmehpsaa.

It was a meat-eater, being a basal (one of the first) theropods, and 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.

Predators such as Ceolophysis had S-shaped necks that they could straighten in an instant to snap up small prey. It also had a flexible neck too.

Name & Discovery[]

It was Named in 1887, the type species of Coelophysis was originally named as a species of Coelurus. Edward Drinker Cope first named Coelophysis in 1889 to name a new genus, outside of Coelurus and Tanystrophaeus to which C. bauri was previously classified in for C. bauri, C. willistoni and C. longicollis.

Sexual Dimorphism[]

There were thought to be 2 species but it was found that males were bigger than females.


Coelophysis is known from a number of complete fossil skeletons of the species C. bauri, which was a lightly built dinosaur which measured up to 3 metres (9.8 feet) in length and which was more than a meter tall at the hips. Paul (1988) estimated the weight of the gracile form at 15 kg (33 lbs), and the weight of the robust form at 20 kilograms (44 lbs). Coelophysis was a bipedal, carnivorous, theropod dinosaur that was a fast and agile runner.

Recent studies on activity levels and the genus occurring in climates that could get colder than previously thought have changed opinions on the animal's integument. This revived an old hypothesis from the 1980s that Coelophysis was covered in feathers. The study indicated only a feathered animal of Coelophysis shape and size could have survived the cold so handily. Many paleontologists has thus begun returning the 1980s reconstructions for an idea of how the animal looked in life.


Coelophysis is a distinct taxonomic unit (genus), composed of two species; C. bauri and C. rhodesiensis (the latter formerly classified as the genus Megapnosaurus). 2 additional originally described species, C. longicollis and C. willistoni, are now considered synonymous with C. bauri. C. rhodesiensis is probably part of this generic complex, and is known from the Jurassic of southern Africa.

Appearance in Media[]

  • Coelophysis appeared In the first episode of Walking with Dinosaurs, where a young female is the main character and the leader of a pack. It is shown hunting lungfish, cynodonts and eating a dying female Postosuchus as well as each other (occasionally) during a drought. Then, when the wet season turned everything green again, a herd of Plateosaurus appeared and drove off the agile little Dinosaurs from a swollen river.
  • Coelophysis also appeared in When Dinosaurs Roamed America, where it appears as two separate species, Coelophysis itself, as a male, and the subspecies, "Syntarsus".
  • It also featured in Mammals Vs Dinos, where it hunts early mammals like Adelobasileus.
  • It also featured in Life After Dinosaurs.
  • Coelophysis appears in the Triassic section of Dinosaur Adventure 3D as “Syntarsus”.
  • Coelophysis makes a cameo appearance in the 1992 PBS miniseries, The Dinosaurs!
  • A Coelophysis appears as a brown needlenose in the ABC sitcom Dinosaurs.
  • It appears in Dinosaurs: Fun, Fact and Fantasy.