Archosauria is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term, which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives; and Avemetatarsalia, which includes birds and their extinct relatives.
Anchisaurus is a genus of basal sauropodomorph dinosaur. It lived during the Early Jurassic Period, and its fossils have been found in the red sandstone of the Portland Formation, Northeastern United States, which was deposited from the Hettangian age into the Sinemurian age, between about 200 and 195 million years ago. Until recently it was classed as a member of Prosauropoda. The genus name Anchisaurus comes from the Greek αγχιanchi-; "near, close" + Greek σαυρος ; "lizard". Anchisaurus was coined as a replacement name for "Amphisaurus", which was itself a replacement name for Hitchcock's "Megadactylus", both of which had already been used for other animals.
Plateosaurus is a genus of plateosaurid dinosaur that lived during the Late Triassic period, around 214 to 204 million years ago, in what is now Central and Northern Europe. Plateosaurus is a basal (early) sauropodomorph dinosaur, a so-called "prosauropod". The type species is Plateosaurus trossingensis; before 2019, that honor was given to Plateosaurus engelhardti, but it was ruled as undiagnostic by the ICZN. Currently, there are three valid species; in addition to P. trossingensis, P. longiceps and P. gracilis are also known. However, others have been assigned in the past, and there is no broad consensus on the species taxonomy of plateosaurid dinosaurs. Similarly, there are a plethora of synonyms at the genus level.
Herrerasaurus is likely a genus of saurischian dinosaur from the Late Triassic period. This genus was one of the earliest dinosaurs from the fossil record. Its name means "Herrera's lizard", after the rancher who discovered the first specimen in 1958 in South America. All known fossils of this carnivore have been discovered in the Ischigualasto Formation of Carnian age in northwestern Argentina. The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 and is the only species assigned to the genus. Ischisaurus and Frenguellisaurus are synonyms.
Thecodontosaurus is a genus of herbivorous basal sauropodomorph dinosaur that lived during the late Triassic period.
Agrosaurus is an extinct genus of thecodontosaurid sauropodomorph probably originating from England that was originally believed to be a Triassic prosauropod from Australia. Agrosaurus would thus be the oldest dinosaur from that country. However, this appears to have been an error, and the material actually appears to come from Thecodontosaurus or a Thecodontosaurus-like animal from Bristol, England. The type species is Agrosaurus macgillivrayi.
Azendohsaurus is an extinct genus of herbivorous archosauromorph reptile from roughly the late Middle to early Late Triassic Period of Morocco and Madagascar. The type species, Azendohsaurus laaroussii, was described and named by Jean-Michel Dutuit in 1972 based on partial jaw fragments and some teeth from Morocco. A second species from Madagascar, A. madagaskarensis, was first described in 2010 by John J. Flynn and colleagues from a multitude of specimens representing almost the entire skeleton. The generic name "Azendoh lizard" is for the village of Azendoh, a local village near where it was first discovered in the Atlas Mountains. It was a bulky quadruped that unlike other early archosauromorphs had a relatively short tail and robust limbs that were held in an odd mix of sprawled hind limbs and raised forelimbs. It had a long neck and a proportionately small head with remarkably sauropod-like jaws and teeth.
Blikanasaurus is a genus of sauropodomorph dinosaur from the late Triassic of South Africa. The generic name Blikanasaurus is derived from Greek, meaning "lizard from Blikana". The species name cromptoni is taken from the surname of A.W. “Fuzz” Crompton, an American paleontologist who led numerous field expeditions in Elliot Formation outcrop localities in South Africa. Blikanasaurus is only known from partial hindlimb bones that were recovered from the lower Elliot Formation (LEF) in the Eastern Cape.
Camelotia is a genus of sauropodomorph dinosaur from the Late Triassic or Early Jurassic in what is now England. Paleontologists are divided on which family it may belong to; in the past, Camelotia has generally been assigned to the prosauropods, but this group of primitive dinosaurs is in constant flux. The genus is now considered a member of the family Melanorosauridae, which includes the first true giant herbivorous dinosaurs.
Avalonianus is a highly dubious and possibly invalid genus of archosaur from the Late Triassic of England. It was first described in 1898 by Harry Seeley with the name Avalonia, but that name was preoccupied, so Oskar Kuhn renamed it in 1961, albeit with no epithet. It was thought to be a prosauropod, but later analysis revealed it was actually a chimera, with the original teeth coming from a non-dinosaurian ornithosuchian, and later-referred post-cranial prosauropod remains. The only sufficient remains attributable to Avalonianus are several now lost fossil teeth from the chimera that were referred to Archosauria.
Euskelosaurus is a sauropodomorph dinosaur from the Late Triassic of South Africa and Lesotho. Fossils have only been recovered from the lower Elliot Formation in South Africa and Lesotho, and in one locality in Zimbabwe.
Orosaurus is a dubious genus of basal sauropodomorph from the Late Triassic of South Africa.
Teratosaurus is a genus of rauisuchians known from the Triassic Stubensandstein of Germany. It is estimated to be 6.2 meters (20.35 ft) long.
Poposauridae is a family of large carnivorous archosaurs which lived alongside dinosaurs during the Late Triassic. They were around 2.5 to 5 metres long. Poposaurids are known from fossil remains from North and South America. While originally believed to be theropod dinosaurs, cladistic analysis has shown them to be more closely related to crocodiles.
Palaeosaurus is a genus of indeterminate archosaur known from two teeth found in the Bromsgrove Sandstone Formation and also either the Magnesian Conglomerate or the Avon Fissure Fill of Clifton, Bristol, England. It has had a convoluted taxonomic history.
Poposaurus is an extinct genus of pseudosuchian archosaur from the Late Triassic of the southwestern United States. It belongs to the clade Poposauroidea, an unusual group of Triassic pseudosuchians that includes sail-backed, beaked, and aquatic forms. Fossils have been found in Wyoming, Utah, Arizona, and Texas. Except for the skull, most parts of the skeleton are known. The type species, P. gracilis, was described and named by Maurice Goldsmith Mehl in 1915. A second species, P. langstoni, was originally the type species of the genus Lythrosuchus. Since it was first described, Poposaurus has been variously classified as a dinosaur, a phytosaur, and a "rauisuchian".
Saurischia is one of the two basic divisions of dinosaurs, classified by their hip structure. Saurischia and Ornithischia were originally called orders by Harry Seeley in 1888 though today most paleontologists classify Saurischia as an unranked clade rather than an order.
Thecodontosauridae is a family of basal sauropodomorph dinosaurs that are part of the Bagualosauria, known from fossil remains found exclusively in the Magnesian Conglomerate of Bristol, England, which dates back to the Rhaetian stage of the Late Triassic. Two genera are known: Agrosaurus and Thecodontosaurus; the former is often considered to be the same animal as the latter.
Asylosaurus is a genus of basal sauropodomorph dinosaur from the Late Triassic Avon Fissure Fill of England. It is based on partial remains, discovered in the autumn of 1834, described in 1836 by Henry Riley and Samuel Stutchbury as pertaining to Thecodontosaurus, that Othniel Charles Marsh brought to Yale University between 1888 and 1890. These remains thus escaped destruction by a bombardment in 1940 during World War II, unlike the original holotype of Thecodontosaurus. Asylosaurus was described in 2007 by Peter Galton. The type species is A. yalensis, referring to Yale. The bones originally came from a Rhaetian-age cave fill at Durdham Down, Clifton, Bristol.
Phytodinosauria is a group of dinosaurs proposed in 1986, combining the Sauropodomorpha and Ornithischia as sister groups, conceptualized as a superorder of herbivorous dinosaurs excluding the carnivorous Theropoda. This hypothesis has been refuted by modern cladistic analysis, showing such a group to be polyphyletic. Modern studies either combine the Theropoda and Sauropodormorpha in the Saurischia or the Theropoda and Ornithischia in the Ornithoscelida.
