Coelophysis‭ (‬Hollow form‭)

Short Info

Coelophysis‭ (‬Hollow form‭)

Phonetic : See-lo-fie-sis.

Named By : Edward Drinker Cope‭ ‬-‭ ‬1889

Diet : Carnivore

Size : Estimated 2.5-3 meters long

Type of Dinosaur : Small Theropod

Type Species : C.‭ ‬bauri (type), C. kayentakatae, C. rhodesiensis. Possibly C. holyokensis.

Found in : South Africa, Zimbabwe USA,‭ ‬New Mexico and Arizona.‭ ‬Quite possibly other areas of the US and even further afield.

When it Lived : Late Triassic, 225-190 million years ago

Coelophysis (/se’lafIsIsor seh-LOF’sis in the traditional sense (/,seloU’faIsIs/SEL-o si:loU’faIsIs/SEE-loF often heard in the last years) was a extinct genus belonging to the coelophysids, a dinosaur species that lived between 221.5 to the year 196 million ago in the latter half of the Triassic Period in what is today the southwest United States and also in South Africa and Zimbabwe.


Coelophysis bauri mountJames St. John, CC BY 2.0, via Wikimedia Commons


Coelophysis was a tiny and slenderly built, ground-dwelling bipedal carnivore that could attain as high as 3 meters (9.8 feet) in length. It’s one of the first dinosaur genera to be identified. Material that resembles similar species has been discovered all over the world in various Late Triassic and Early Jurassic formations.

The species of type C. bauri, originally assigned to the Genus Coelurus by Edward Drinker Cope in 1887 It was named by him in 1889. It is believed that the names Longosaurus and Rioarribasaurus are both synonymous with Coelophysis. Another dinosaur Genus, Megapnosaurus, has also been identified as an alternative. Theropods of the primitive era are known for being among the dinosaur genera that has the highest number of specimens.

In 1887, the original kind of Coelophysis was first named an eukaryotic species of Coelurus. Edward Drinker Cope first named Coelophysis in 1889 in order to create an entirely new genus in addition to Coelurus as well as Tanystropheus with the genus C. bauri was previously identified as C. bauri, C. willistoni, and C. Longicollis. A fossil hunter who was an amateur working in the name of Cope, David Baldwin, discovered the first dinosaur remains in 1881, in the Chinle Formation in northwestern New Mexico. Then, in 1887, Cope referred the specimens taken to two species: C. bauri and C. longicollis from the Genus Coelurus. In the year 1887, Cope changed the specimens to a different Genus, called Tanystropheus. A few months later Cope changed his classification after recognizing the differences between vertebrae. He named the species Coelophysis and included C. bauri as the most common species. It was named in honor of Georg Baur, a comparative anatomist with ideas identical to Cope’s. The name Coelophysis is derived in the Greek words coilos/koilos (meaning hollow) along with phusis/physis (meaning “form”) and, therefore “hollow form” which is an allusion to the hollow vertebrae. But, the first discoveries were not well preserved to provide a full picture of the new dinosaur. The year 1947 saw the discovery of a large graveyard consisting of Coelophysis fossils was discovered through George Whitaker, the assistant of Edwin H. Colbert, in New Mexico, at the Ghost Ranch, close to the initial discovery. American Museum of Natural History paleontologist Edwin H. Colbert conducted an extensive examination of all fossils discovered up to that date, and classified them under Coelophysis. The Ghost Ranch fossils were so abundant, with numerous well-preserved and fully articulated specimens that one has become the standard specimen, or the prototype specimen, across the entire family replacing the previous poor-quality specimen.

“Syntarsus” rhodesiensis was first identified in Raath (1969) in 1969 and was assigned to Podokesauridae. The taxon “Podokesauridae”, was abandoned because its original specimen was destroyed by fire, and it is no longer able to be compared with new discoveries. Through the years, paleontologists classified this genus as Ceratosauridae (Welles 1984), Procompsognathidae (Parrish and Carpenter 1986) and Ceratosauria (Gauthier 1986). In 2004 “Syntarsus” was found synonymous with Coelophysis by Tykoski and Rowe (2004). Ezcurra Novas (2007) and Novas (2007) as well as Ezcurra (2007) have also determined they believed that “Syntarsus” was synonymous with Coelophysis this is the present consensus in science.

Coelophysis is identified through a variety completely fossilized skeletons from this kind C. bauri which was a thinly built dinosaur, measuring up to 3 meters (9.8 feet) long[18] was over a meter high on the hips. Paul (1988) estimates that the weight of the weak version at 15 kilograms (33 lbs) while it was the same for the strong one at 20 kilograms (44 lbs). Coelophysis was an bipedal carnivorous dinosaur that was a quick and agile run. While it was an early dinosaur that evolved, the body shape of the theropod had already advanced significantly from animals like Herrerasaurus or Eoraptor. Coelophysis’s torso Coelophysis follows the basic theropod body design, but the pectoral girdle has unique characteristics. C. bauri was the only dinosaur to have the furcula (wishbone) that was the first known specimen of a dinosaur. Coelophysis is also able to preserve the original condition of having four fingers (manus). It only had three functional fingers, and the fourth was found inside the skin of the hand.

Coelophysis was a tinier hip and forelimbs that were adapted to grasp prey and feet with narrow legs. The neck and tail of the animal were long and slim. The hindlimbs and pelvis that comprise C. bauri have minor variations from Theropod’s body structure. It features an open acetabulum as well as the straight ankle hinges that make up the Dinosauria. The hindlimb terminated in the form of a foot with three toes (pes) and the hallux raised. The tail was a unique design in its interlocking vertebrae that formed an unrigid lattice that was believed to prevent its tail moving upwards and down.

Coelophysis was born with a long, narrow head (approximately 300 mm (0.9 inches)) and large forward-facing eyes, which gave the animal stereoscopic vision, and, as a result, superior depth perception. Rinehart et al. (2004) discussed the complete sclerotic circle discovered for an infant Coelophysis bauri (specimen NMMNH P-4200) and examined it against data from the sclerotic rings of reptiles as well as birds. They discovered the Coelophysis could be a regular visually-oriented predator. The study revealed that vision in Coelophysis outperformed Lizards and was comparable to the vision of modern predators of birds. Eyes of Coelophysis seem to be closest to the eyes of hawks and eagles with a superior capacity of accommodation. It also suggests low night-vision, which could suggest that the dinosaur had a circular rather than split pupil.

Coelophysis was characterized by an elongated snout with large fenestrae that reduced the weight of the skull and the narrow struts of bones helped to preserve the structure of the skull. The neck had a distinct curvature called sigmoid. The braincase is identified as Coelophysis bauri, but only a few details could be obtained since the skull had been crushed. Contrary to other theropods it was the case that the cranial ornamentation of Coelophysis did not lie on the top of the skull. A low, laterally raised bony ridges were found on the dorsolateral side of the lacrimal and nasal bones within the skull, just above the antorbital bone.

Source: Wikipedia