Dasygnathoides is an extinct genus of pseudosuchian from the Late Triassic (Carnian) Lossiemouth Sandstone of Scotland.
Ornithosuchus is an extinct genus of pseudosuchians from the Late Triassic (Carnian) Lossiemouth Sandstone of Scotland. It was originally thought to be the ancestor to the carnosaurian dinosaurs, but it is now known to be more closely related to crocodilians than to dinosaurs.
Venaticosuchus is a genus of pseudosuchian archosaurs from the family Ornithosuchidae. Known from a single species, Venaticosuchus rusconii, this genus is described based on an incomplete skull and jaw collected from the Late Triassic (Carnian) Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina, which was deposited around 230 million years ago. This fossil material has been termed the holotype specimen PVL 2578. Venaticosuchus incorporated a myriad of features present in the other two genera of ornithosuchids, Ornithosuchus and Riojasuchus. However, it also had several unique traits, relating to the lower jaw.
Gracilisuchus is an extinct genus of tiny pseudosuchian from the Late Triassic of Argentina. It contains a single species, G. stipanicicorum, which is placed in the clade Suchia, close to the ancestry of crocodylomorphs. Both the genus and the species were first described by Alfred Romer in 1972.
Riojasuchus is an extinct genus of ornithosuchid archosaur from the Late Triassic (Norian) of Argentina. Ornithosuchidae was a widespread family of facultatively bipedal pseudosuchians with adaptations for scavenging. Riojasuchus is notable as one of the youngest and most complete members of the family. The type and only known species, Riojasuchus tenuisceps, was named and described by José Bonaparte in 1967. It was one of the first of many well-preserved Triassic archosaurs to be discovered in Argentina. The holotype specimen, PVL 3827, was found in the Los Colorados Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina.
Hesperosuchus is an extinct genus of crocodylomorph reptile that contains a single species, Hesperosuchus agilis. Remains of this pseudosuchian have been found in Late Triassic (Carnian) strata from Arizona and New Mexico. Because of similarities in skull and neck anatomy and the presence of hollow bones Hesperosuchus was formerly thought to be an ancestor of later carnosaurian dinosaurs, but based on more recent findings and research it is now known to be more closely related to crocodilians rather than dinosaurs.
Prestosuchus is an extinct genus of pseudosuchian in the group Loricata, which also includes Saurosuchus and Postosuchus. It has historically been referred to as a "rauisuchian", and was the defining member of the family Prestosuchidae, though the validity of both of these groups is questionable: Rauisuchia is now considered paraphyletic and Prestosuchidae is polyphyletic in its widest form.
Aetosauroides is an extinct genus of aetosaur from the Late Triassic of South America. It is one of four aetosaurs known from South America, the others being Neoaetosauroides, Chilenosuchus and Aetobarbakinoides. Three species have been named: the type species A. scagliai, A. subsulcatus and A. inhamandensis. Fossils have been found in the Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina and the Santa Maria Formation in the Paraná Basin in southeastern Brazil. The strata date to the late Carnian and early Norian stages, making Aetosauroides one of the oldest aetosaurs.
Ornithosuchidae is an extinct family of pseudosuchian archosaurs from the Triassic period. Ornithosuchids were quadrupedal and facultatively bipedal, meaning that they had the ability to walk on two legs for short periods of time. They had distinctive, downturned snouts, unique, "crocodile-reversed" ankle bones, and several other features that distinguish them from other archosaurs. Ornithosuchids were geographically widespread during the Carnian and Norian stages of the Late Triassic with members known from Argentina, Brazil, and the United Kingdom. Four genera, comprising Ornithosuchus, Venaticosuchus, Dynamosuchus, and Riojasuchus are presently known. The family was first erected by German paleontologist Friedrich von Huene in 1908.
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age, and is notable for its fossils of cynodonts, "rauisuchian" pseudosuchians, and early dinosaurs and other dinosauromorphs, including the herrerasaurid Staurikosaurus, the basal sauropodomorphs Buriolestes and Saturnalia, and the lagerpetid Ixalerpeton. The formation is named after the city of Santa Maria in the central region of Rio Grande do Sul, where outcrops were first studied.
The Los Colorados Formation is a sedimentary rock formation of the Ischigualasto-Villa Unión Basin, found in the provinces of San Juan and La Rioja in Argentina. The formation dates back to the Norian age of the Late Triassic.
Proterochampsa is an extinct genus of proterochampsid, non-archosaur archosauriformes from the Late Triassic of South America. The genus forms a monophyly within the family Proterochampsidae, and more broadly within the clade Proterochampsia. Like other proterochampsids, Proterochampsa are quadruped tetrapods superficially similar in appearance to modern crocodiles, although the two groups are not closely related. Proterochampsids can be distinguished from other related archosauriformes by characters such as a dorsoventrally flattened, triangular skull with a long, narrow snout at the anterior end and that expands transversally at the posterior end, asymmetric feet, and a lack of postfrontal bones in the skull, with the nares located near the midline. Proterochampsa is additionally defined by characters of dermal sculpturing consisting of nodular protuberances on the skull, antorbital fenestrae facing dorsally, and a restricted antorbital fossa on the maxilla. The genus comprises two known species: Proterochampsa barrionuevoi and Proterochampsa nodosa, with the species names potentially recalling “new neighborhood” in Spanish and the large nodular growths of P. nodosa, respectively. P. barrionuevoi specimens have been discovered in the Ischigualasto Formation in northwestern Argentina, while P. nodosa specimens have been found in the Santa Maria supersequence in southeastern Brazil. The two species are distinct in several characters, including that P. nodosa has larger, more well-developed nodular protuberances, a more gradually narrowing snout, and a higher occiput than P. barrionuevoi. Of the two, P. nodosa is thought to have less derived features than P. barrionuevoi.
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.
The Chañares Formation is a Carnian-age geologic formation of the Ischigualasto-Villa Unión Basin, located in La Rioja Province, Argentina. It is characterized by drab-colored fine-grained volcaniclastic claystones, siltstones, and sandstones which were deposited in a fluvial to lacustrine environment. The formation is most prominently exposed within Talampaya National Park, a UNESCO World Heritage Site within La Rioja Province.
Tarjadia is an extinct genus of erpetosuchid pseudosuchian, distantly related to modern crocodilians. It is known from a single species, T. ruthae, first described in 1998 from the Middle Triassic Chañares Formation in Argentina. Partial remains have been found from deposits that are Anisian-Ladinian in age. Long known mostly from osteoderms, vertebrae, and fragments of the skull, specimens described in 2017 provided much more anatomical details and showed that it was a fairly large predator. Tarjadia predates known species of aetosaurs and phytosaurs, two Late Triassic groups of crurotarsans with heavy plating, making it one of the first heavily armored archosaurs. Prior to 2017, most studies placed it outside Archosauria as a member of Doswelliidae, a family of heavily armored and crocodile-like archosauriforms. The 2017 specimens instead show that it belonged to the Erpetosuchidae.
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.
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.
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.
Rugarhynchos is an extinct genus of doswelliid archosauriform from the Late Triassic of New Mexico. The only known species is Rugarhynchos sixmilensis. It was originally described as a species of Doswellia in 2012, before receiving its own genus in 2020. Rugarhynchos was a close relative of Doswellia and shared several features with it, such as the absence of an infratemporal fenestra and heavily textured skull bones. However, it could also be distinguished by many unique characteristics, such as a thick diagonal ridge on the side of the snout, blunt spikes on its osteoderms, and a complex suture between the quadratojugal, squamosal, and jugal. Non-metric multidimensional scaling and tooth morphology suggest that Rugarhynchos had a general skull anatomy convergent with some crocodyliforms, spinosaurids, and phytosaurs. However, its snout was somewhat less elongated than those other reptiles.
Incertovenator is an extinct genus of archosauriform reptile, likely an archosaur, of uncertain affinities. Its unstable position is a result of possessing a number features found in both the bird-line avemetatarsalian archosaurs and the crocodylian-line pseudosuchians. The type and only known species is I. longicollum, which is known from single specimen discovered in the Late Triassic Ischigualasto Formation of Argentina. Incertovenator is known almost entirely by its vertebral column. This indicates that it had a relatively long neck, leading to its uncertain classification due to the convergent evolution of elongated neck vertebrae in both avemetatarsalian and pseudosuchian archosaurs.
