Coelophysidae is a family of primitive carnivorous theropod dinosaurs. Most species were relatively small in size. The family flourished in the Late Triassic and Early Jurassic periods, and has been found on numerous continents. Many members of Coelophysidae are characterized by long, slender skulls and light skeletons built for speed. One member, Coelophysis, displays the earliest known furcula in a dinosaur.
Under cladistic analysis, Coelophysidae was first defined by Paul Sereno in 1998 as the most recent common ancestor of Coelophysis bauri and Procompsognathus triassicus, and all of that common ancestor's descendants. However, Tykoski (2005) has advocated for the definition to change to include the additional taxa of "Syntarsus" kayentakatae and Segisaurus halli. Coelophysidae is part of the superfamily Coelophysoidea, which in turn is a subset of the larger Neotheropoda clade. As part of Coelophysoidea, Coelophysidae is often placed as sister to the Dilophosauridae family, however, the monophyly of this clade has often been disputed. The older term "Podokesauridae", named 14 years prior to Coelophysidae (which would normally grant it priority), is now usually ignored, since its type specimen was destroyed in a fire and can no longer be compared to new finds.
|Skull comparison of Coelophysidae (Coelophysis rhodesiensis at the top left, Panguraptor lufengensis at the top right, Coelophysis bauri at the bottom left, Coelophysis kayentakatae at the bottom right)|
Coelophysids are characterized by slender, skinny builds and long, narrow skulls with large fenestrae to allow for a lighter skull. They are fairly primitive theropods, and so have fairly basal characteristics, such as hollow air sacs in the cervical vertebrae and obligate bipedalism. Their slender builds allowed them to be fast and agile runners. All known members of Coelophysidae are carnivores. One species, Coelophysis bauri has the oldest known furcula (wishbone) of any dinosaur.
It has also been speculated that some species within Coelophysidae, namely Coelophysis bauri, displayed cannibalism, although the fossil evidence behind these claims has been heavily debated (Rinehart et al., 2009; Gay, 2002; Gay, 2010).
Coelophysidae is part of the larger superfamily of Coelophysoidea, which contains Dilophosauridae, Liliensternus, and Zupaysaurus in addition to Coelophysidae. Coelophysoidea, in turn, is part of the larger clade of Neotheropoda. Of the two major families within Coelophysoidea, Dilophosauridae and Coelophysidae, Coelophysidae is considered to be more basal.
Fossils of members of Coelophysidae have been found across many continents, including North America, South America, Europe, Asia, and Africa. Powellvenator podocitus was discovered in Northwestern Argentina. Procompsognathus triassicus was discovered in Germany, and Camposaurus arizonensis is from Arizona in North America. No coelophysid fossils were known from Asia until the discovery of Panguraptor lufengensis in 2014 in the Yunnan Province of China. The genus Coelophysis has been found in North America, South Africa, and Zimbabwe.
Averostra, or "bird snouts", is a clade that includes most theropod dinosaurs that have a promaxillary fenestra (fenestra promaxillaris), an extra opening in the front outer side of the maxilla, the bone that makes up the upper jaw. Two groups of averostrans, the Ceratosauria and the Orionides, survived into the Cretaceous period. When the Cretaceous–Paleogene extinction event occurred, ceratosaurians and two groups of orionideans within the clade Coelurosauria, the Tyrannosauroidea and Maniraptoriformes, were still extant. Only one subgroup of maniraptoriformes, Aves, survived the extinction event and persisted to the present day.Avetheropoda
Avetheropoda, or "bird theropods", is a clade that includes carnosaurians and coelurosaurs to the exclusion of other dinosaurs.Camposaurus
Camposaurus ( KAMP-o-SOR-əs) is a coelophysoid dinosaur genus from the Norian stage of the Late Triassic period of North America. The pertinent fossil remains date back to the early to middle Norian stage, and is widely regarded as the oldest known neotheropod.Cerapoda
Cerapoda ("ceratopsians and ornithopods") is a clade of the dinosaur order Ornithischia.Coelophysis rhodesiensis
Coelophysis rhodesiensis is an extinct species of coelophysid theropod dinosaur that lived approximately 188 million years ago during the early part of the Jurassic Period in what is now Africa. The species was a small to medium-sized, lightly built, ground-dwelling, bipedal carnivore, that could grow up to 3 m (9.8 ft) long. It was formerly called Syntarsus, but that name was already taken by a beetle, and was subsequently given the name Megapnosaurus by Ivie, Ślipiński & Węgrzynowicz, in 2001, though many subsequent studies have classified it in the genus Coelophysis.Coelophysoidea
Coelophysoidea were common dinosaurs of the Late Triassic and Early Jurassic periods. They were widespread geographically, probably living on all continents. Coelophysoids were all slender, carnivorous forms with a superficial similarity to the coelurosaurs, with which they were formerly classified, and some species had delicate cranial crests. Sizes range from about 1 to 6 m in length. It is unknown what kind of external covering coelophysoids had, and various artists have portrayed them as either scaly or feathered. Some species may have lived in packs, as inferred from sites where numerous individuals have been found together.
Examples of coelophysoids include Coelophysis, Procompsognathus and Liliensternus. Most dinosaurs formerly referred to as being in the dubious taxon "Podokesauridae" are now classified as coelophysoids.Jingshanosaurus
Jingshanosaurus (meaning "Jingshan lizard") is a genus of sauropodomorph dinosaurs from the early Jurassic period.Kayentavenator
Kayentavenator (meaning "Kayenta hunter") is a small carnivorous dinosaur genus which lived during the Early Jurassic Period; fossils were recovered from the Kayenta Formation of northeastern Arizona and were described in 2010.Lepidus praecisio
Lepidus is a genus of extinct coelophysoidean theropod from the Upper Triassic of the United States. It lived in the Otis Chalk localities of the Dockum Group in Texas, around 223 million years ago.Lucianovenator
Lucianovenator is an extinct genus of coelophysoid theropod dinosaur which lived in Argentina during the Triassic. The genus name Lucianovenator translates to "Luciano's hunter", in reference Don Luciano Leyes, who first reported the remains. The species name bonoi refers to Tulio del Bono, a local scientific authority who collaborated on the describers' research. It is one of the few neotheropods known from South America.Neotheropoda
Neotheropoda (meaning "new theropods") is a clade that includes coelophysoids and more advanced theropod dinosaurs, and the only group of theropods who survived the Triassic–Jurassic extinction event. Yet all of the neotheropods became extinct during the early Jurassic period except for Averostra.Notatesseraeraptor
Notatesseraeraptor ("feature mosaic tile thief"; from the Latin "nota", feature; "tesserae", tiles used to make a mosaic, in reference to the mixture of features normally found on dilophosaurids and coelophysoids; and "raptor", thief) is a genus of carnivorous theropod dinosaur that lived during the Late Triassic of what is now Switzerland. It was an early member of Neotheropoda with affinities to Dilophosaurus and Averostra. The new genus and species Notatesseraeraptor frickensis was named by Marion Zahner and colleagues in 2019.Since 1961, at the clay pit of Gruhalde, exploited by Tonwerke Keller, numerous fossils of Plateosaurus have been found. At a somewhat higher layer, in the spring of 2006, amateur paleontologist Michael Fisher discovered the postcranial skeleton of a small theropod. In 2009, the skull was secured. The fossils were unearthed and prepared by Ben Pabst and team. Initially the skeleton was provisionally referred to Coelophysidae. In 2008, parts of the postcranial skeleton were described in a master's thesis by Jasmina Christine Hugi. Lui Unterassner described the shoulder girdle and stomach content in his thesis of 2009, while Marion Zahner dedicated a thesis to the skull in 2014.In 2019, the type species Notatesseraeraptor frickensis gen. et sp. nov. was named and described by Marion Zahner and Winand Brinkmann. The generic name combines the Latin nota, "trait", tesserae, "mosaic tiles", and raptor, "predator". It refers to it being a carnivorous species showing a mix of traits of the Dilophosauridae and Coelophysoidea. The specific name refers to a provenance from the municipality of Frick in the Aargau. It represents the first Mesozoic theropod named from Switzerland.Orionides
Orionides is a clade of tetanuran theropod dinosaurs from the Middle Jurassic to the Present. The clade includes most theropod dinosaurs, including birds.Panguraptor
Panguraptor ("Pangu [a Chinese god] plunderer") is a genus of coelophysid theropod dinosaur known from fossils discovered in Lower Jurassic rocks of southern China. The type and only known species is Panguraptor lufengensis. The generic name refers to the deity Pangu but also to the supercontinent Pangaea for which in a geological context the same characters are used: 盘古. Raptor means "seizer", "robber" in Latin. The specific name is a reference to the Lufeng Formation.The holotype specimen was recovered on 12 October 2007 from the Lufeng Formation of Yunnan, which is noted for sauropodomorph fossils. It was described in 2014 by You Hai-Lu and colleagues.Podokesaurus
Podokesaurus ("swift-footed lizard") was a small carnivorous dinosaur that lived during the Pliensbachian–Toarcian stages of the Early Jurassic Period, and as such is one of the earliest known dinosaurs to inhabit the eastern United States.Procompsognathus
Procompsognathus is an extinct genus of coelophysid theropod dinosaur that lived approximately 210 million years ago during the later part of the Triassic Period, in what is now Germany. Procompsognathus was a small-sized, lightly built, ground-dwelling, bipedal carnivore, that could grow up to 1 m (3.3 ft) long.Pterospondylus
Pterospondylus (meaning "winged vertebra") is a dubious genus of theropod dinosaur from the Late Triassic. It was a coelophysoid theropod which lived in what is now Germany (Trossingen Formation). The type species, Pterospondylus trielbae, was described by Jaekel in 1913-14 for a single back vertebra. Sometimes, it is aligned with Procompsognathus, or even considered to be synonymous with it, despite being based on a vertebra that is twice the size of the corresponding bone in Procompsognathus.The specific name trielbae is derived from "Tri", in reference to the Triassic period, and "Elba", which points to the Elbe River area.Sarcosaurus
Sarcosaurus (meaning "flesh lizard") is a genus of theropod dinosaur, roughly 3.5 metres (11 ft) long. It lived during the Sinemurian stage of the Early Jurassic, about 194 million years ago. Sarcosaurus is one of the earliest known Jurassic theropods, and one of only a handful of theropod genera from this time period.Segisaurus
Segisaurus (meaning "Segi canyon lizard") is a genus of small coelophysoid theropod dinosaur, that measured approximately 1 metre (3.3 feet) in length. The only known specimen was discovered in early Jurassic strata in Tsegi Canyon, Arizona, for which it was named. Segisaurus is the only dinosaur to have ever been excavated from the area.