Archosauromorpha is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs rather than lepidosaurs. Archosauromorphs first appeared during the late Middle Permian or Late Permian, though they became much more common and diverse during the Triassic period.
Proterosuchus is an extinct genus of archosauriform reptiles that lived during the Early Triassic. It contains three valid species: the type species P. fergusi and the referred species P. alexanderi and P. goweri. All three species lived in what is now South Africa. The genus was named in 1903 by the South African paleontologist Robert Broom. The genus Chasmatosaurus is a junior synonym of Proterosuchus.
Tasmaniosaurus is an extinct genus of archosauromorph reptile known from the Knocklofty Formation of West Hobart, Tasmania, Australia. The type species is T. triassicus. This genus is notable not only due to being one of the most complete Australian Triassic reptiles known, but also due to being a very close relative of Archosauriformes. Once believed to be a proterosuchid, this taxon is now believed to have been intermediate between advanced non-archosauriform archosauromorphs such as Prolacerta, and basal archosauriforms such as Proterosuchus. Features traditionally used to define Archosauria and later Archosauriformes, such as the presence of an antorbital fenestra and serrated teeth, are now known to have evolved prior to those groups due to their presence in Tasmaniosaurus.
Mesosuchus is an extinct genus of basal Rhynchosaur from early Middle Triassic deposits of Eastern Cape, South Africa. It is known from the holotype SAM 5882, a partial skeleton, and from the paratypes SAM 6046, SAM 6536, SAM 7416 and SAM 7701 from the Aliwal North Euparkeria site. Mesosuchus is quite small, spanning around 30 cm in length. Mesosuchus was discovered and named by David Meredith Seares Watson in 1912.
Luperosuchus is an extinct genus of loricatan pseudosuchian reptile which contains only a single species, Luperosuchus fractus. It is known from the Chañares Formation of Argentina, within strata belonging to the latest Ladinian stage of the late Middle Triassic, or the earliest Carnian of the Late Triassic. Luperosuchus was one of the largest carnivores of the Chañares Formation, although its remains are fragmentary and primarily represented by a skull with similarities to Prestosuchus and Saurosuchus.
Yarasuchus is an extinct genus of avemetatarsalian archosaur that lived during the Anisian stage of the Middle Triassic of India. The genus was named and described in 2005 from a collection of disarticulated but fairly complete fossil material found from the Middle Triassic Yerrapalli Formation. The material is thought to be from two individuals, possibly three, with one being much more complete and articulated than the other. The type and only species is Y. deccanensis. Yarasuchus was a quadruped roughly 2–2.5 metres (6.6–8.2 ft) long, with an elongated neck and tall spines on its vertebrae. Unlike other quadrupedal Triassic reptiles, the limbs and shoulders of Yarasuchus were slender, and more like those of ornithodirans.
Suchia is a clade of archosaurs containing the majority of pseudosuchians. It was defined as the least inclusive clade containing Aetosaurus ferratus, Rauisuchus tiradentes, Prestosuchus chiniquensis, and Crocodylus niloticus by Nesbitt (2011). Generally the only pseudosuchian group which is omitted from Suchia is the family Ornithosuchidae, although at least one analysis classifies ornithosuchids as close relatives of erpetosuchids and aetosaurs. Phytosaurs are also excluded from Suchia, although it is not certain whether they qualify as pseudosuchians in the first place.
Archeopelta is an extinct genus of carnivorous archosaur from the late Middle or early Late Triassic period. It was a 2 m (6 ft) long predator which lived in what is now southern Brazil. Its exact phylogenetic placement within Archosauriformes is uncertain; it was originally classified as a doswelliid, but subsequently it was argued to be an erpetosuchid archosaur.
Teraterpeton is an extinct genus of trilophosaurid archosauromorphs. It is known from a partial skeleton from the Late Triassic Wolfville Formation of Nova Scotia, described in 2003. It has many unique features seen in no other related form, including an elongated, toothless snout and large openings for the nostrils. Because of this, Teraterpeton was originally placed in its own family, Teraterpetidae, related to Trilophosaurus. Newer studies generally place it within Trilophosauridae.
Erpetosuchidae is an extinct family of pseudosuchian archosaurs. Erpetosuchidae was named by D. M. S. Watson in 1917 to include Erpetosuchus. It includes the type species Erpetosuchus granti from the Late Triassic of Scotland, Erpetosuchus sp. from the Late Triassic of eastern United States and Parringtonia gracilis from the middle Middle Triassic of Tanzania; the group might also include Dyoplax arenaceus from the Late Triassic of Germany, Archeopelta arborensis and Pagosvenator candelariensis from Brazil and Tarjadia ruthae from Argentina.
Pamelaria is an extinct genus of allokotosaurian archosauromorph reptile known from a single species, Pamelaria dolichotrachela, from the Middle Triassic of India. Pamelaria has sprawling legs, a long neck, and a pointed skull with nostrils positioned at the very tip of the snout. Among early archosauromorphs, Pamelaria is most similar to Prolacerta from the Early Triassic of South Africa and Antarctica. Both have been placed in the family Prolacertidae. Pamelaria, Prolacerta, and various other Permo-Triassic reptiles such as Protorosaurus and Tanystropheus have often been placed in a group of archosauromorphs called Protorosauria, which was regarded as one of the most basal group of archosauromorphs. However, more recent phylogenetic analyses indicate that Pamelaria and Prolacerta are more closely related to Archosauriformes than are Protorosaurus, Tanystropheus, and other protorosaurs, making Protorosauria a polyphyletic grouping.
Aenigmastropheus is an extinct genus of early archosauromorph reptiles known from the middle Late Permian Usili Formation of Songea District, southern Tanzania. It contains a single species, Aenigmastropheus parringtoni, known solely from UMZC T836, a partial postcranial skeleton of a mature individual. It was collected in 1933, and first described in 1956, as a "problematic reptile" due to its unique morphology. Therefore, a binomial name was erected for this specimen in 2014. Aenigmastropheus was probably fully terrestrial.
Nundasuchus is an extinct genus of crurotarsan, possibly a suchian archosaur related to Paracrocodylomorpha. Remains of this genus are known from the Middle Triassic Manda beds of southwestern Tanzania. It contains a single species, Nundasuchus songeaensis, known from a single partially complete skeleton, including vertebrae, limb elements, osteoderms, and skull fragments.
Kadimakara is an extinct genus of early archosauromorph reptile from the Arcadia Formation of Queensland, Australia. It was seemingly a very close relative of Prolacerta, a carnivorous reptile which possessed a moderately long neck. The generic name Kadimakara references prehistoric creatures from Aboriginal myths which may have been inspired by ice-age megafauna. The specific name K. australiensis relates to the fact that it was found in Australia. Prolacerta and Kadimakara were closely related to the Archosauriformes, a successful group which includes archosaurs such as crocodilians, pterosaurs, and dinosaurs.
Boreopricea is an extinct genus of archosauromorph reptile from the Early Triassic of arctic Russia. It is known from a fairly complete skeleton discovered in a borehole on Kolguyev Island, though damage to the specimen and loss of certain bones has complicated study of the genus. Boreopricea shared many similarities with various other archosauromorphs, making its classification controversial. Various studies have considered it a close relative of Prolacerta, tanystropheids, both, or neither. Boreopricea is unique among early archosauromorphs due to possessing contact between the jugal and squamosal bones at the rear half of the skull.
Aenigmaspina is an extinct genus of enigmatic pseudosuchian (=crurotarsan) archosaur from the Late Triassic of the United Kingdom. Its fossils are known from the Pant-y-ffynnon Quarry in South Wales, of which its type and only known species is named after, A. pantyffynnonensis. Aenigmaspina is characterised by the unusual spines on its vertebrae, which are broad and flat on top with a unique 'Y' shape. Although parts of its skeleton is relatively well known, the affinities of Aenigmaspina to other pseudosuchians are unclear, although it is possibly related to families Ornithosuchidae, Erpetosuchidae or Gracilisuchidae.
Fraxinisaura is an extinct genus of basal lepidosauromorph reptile known from the Middle Triassic of Germany. The only known species is Fraxinisaura rozynekae. It possessed an elongated snout, unique features of the teeth, and an ilium which was intermediate in orientation between sphenodontians and squamates. Based on characteristics of the maxilla, it is considered a close relative of Marmoretta from the Middle Jurassic of the United Kingdom, resolving a ghost lineage between that genus and other Triassic basal lepidosauromorphs.
Polymorphodon is an extinct genus of archosauriform reptile from the Middle Triassic of Germany. The only known species is Polymorphodon adorfi, discovered in Lower Keuper deposits at a quarry in Eschenau, Germany. Polymorphodon is notable for its heterodont dentition, with long and conical premaxillary teeth followed by thin maxillary teeth with large serrations. Maxillary teeth near the back of the mouth are short and leaf-shaped, similar to some living and extinct reptiles with a herbivorous or omnivorous diet. This may suggest that Polymorphodon had some reliance on plants in its diet, a rarity among basal archosauriforms, most of which are carnivores.
Issi is a plateosaurid dinosaur described in 2021 from the Late Triassic Fleming Fjord Formation of Greenland. It contains one species, Issi saaneq; the full binomial name means "cold bone".
Parvosaurus is an extinct species of rhynchocephalian reptile known from the Late Triassic of Germany.
