"Rauisuchia" is a paraphyletic group of mostly large and carnivorous Triassic archosaurs. Rauisuchians are a category of archosaurs within a larger group called Pseudosuchia, which encompasses all archosaurs more closely related to crocodilians than to birds and other dinosaurs. First named in the 1940s, Rauisuchia was a name exclusive to Triassic archosaurs which were generally large, carnivorous, and quadrupedal with a pillar-erect hip posture, though exceptions exist for all of these traits. Rauisuchians, as a traditional taxonomic group, were considered distinct from other Triassic archosaur groups such as early dinosaurs, phytosaurs, aetosaurs, and crocodylomorphs.
Postosuchus, meaning "Crocodile from Post", is an extinct genus of rauisuchid reptiles comprising two species, P. kirkpatricki and P. alisonae, that lived in what is now North America during the Late Triassic. Postosuchus is a member of the clade Pseudosuchia, the lineage of archosaurs that includes modern crocodilians. Its name refers to Post Quarry, a place in Texas where many fossils of the type species, P. kirkpatricki, were found. It was one of the apex predators of its area during the Triassic, larger than the small dinosaur predators of its time. It was a hunter which probably preyed on large bulky herbivores like dicynodonts and many other creatures smaller than itself.
Arizonasaurus was a ctenosauriscid archosaur from the Middle Triassic. Arizonasaurus is found in the Middle Triassic Moenkopi Formation of northern Arizona. A fairly complete skeleton was found in 2002 by Sterling Nesbitt. The taxon has a large sailback formed by elongated neural spines of the vertebrae. The type species, Arizonasaurus babbitti, was named by Samuel Paul Welles in 1947.
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.
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".
Lotosaurus is an extinct genus of sail-backed poposauroid known from Hunan Province of central China.
Batrachotomus is a genus of prehistoric archosaur. Fossils of this animal have been found in southern Germany and dated from the Ladinian stage of the Middle Triassic period, around 242 to 237 million years ago. Batrachotomus was described by palaeontologist David J. Gower 22 years after its discovery.
Ctenosauriscus is an extinct genus of sail-backed poposauroid archosaur from Early Triassic deposits of Lower Saxony in northern Germany. It gives its name to the family Ctenosauriscidae, which includes other sail-backed poposauroids such as Arizonasaurus. Fossils have been found in latest Olenekian deposits around 247.5-247.2 million years old, making it one of the first known archosaurs.
Fenhosuchus is an extinct genus of archosauriform. The holotype, IVPP V 2697, and referred materials have been found in the Hsishihwa locality at Wuhsiang, China, from the Upper Ermaying Formation. The locality dates back to the Anisian stage of the Middle Triassic. The genus was named after the Fen River in Shanxi Province from which specimens were found. It may prove to be a chimera being composed of material from several different animals. Some material were believed to represent a rauisuchid. The calcaneum of Fenhosuchus seems to belong to an erythrosuchid or other basal archosauriform. Much of the material of the tarsal bones seem to be similar to those of the genus Shansisuchus. According to Nesbitt (2009) the assessment of Gower (2000) was correct, the holotype is a mix of Shansisuchus remains and a possible fragment from a paracrocodylomorph or a dinosauriform. Thus, Fenhosuchus cannot be considered a rauisuchian.
Jushatyria is an extinct genus of archosaur. Fossils have been found in the Koltaevo III Locality, district of Kumertau near the Ural Mountains in European Russia from the Bukobay Gorizont. The locality dates back to the Ladinian stage of the Middle Triassic. Additional material has been described from a locality on the banks of the Berdyanka River that was previously assigned to a rauisuchid-like archosaur. However, this material differed from the original specimens because it lacked slit-like antorbital openings accompanying the antorbital fossa. Nesbitt (2009) and Gower and Sennikov (2000) suggested that all material currently referred to Jushatyria most likely does not represent a single taxon. Thus, Jushatyria is known only from its holotype PIN 2867/5, an incomplete left maxilla. As the maxilla is damaged, many "rauisuchian" characters could not be verified. Jushatyria was reassigned as an indeterminate archosaur on the basis of the presence of an antorbital fossa on the lateral surface of the maxilla.
Tsylmosuchus is an extinct genus of proterosuchid archosauriform reptile known from Western Russia. Fossils referred to Tsylmosuchus occurred over a wide area in sediments corresponding to the Induan and Olenekian stages of the Early Triassic. Most of these fossils are fragmentary neck vertebrae which were originally reported as sharing similarities with crocodile-line archosaurs (pseudosuchians) such as Mandasuchus. As a result, Tsylmosuchus was first described as part of the family Rauisuchidae, making it supposedly one of the oldest known archosaurs. However, its fragmentary remains do not show any of the distinguishing features of rauisuchids or even pseudosuchians in general, so Tsylmosuchus has more recently been interpreted as an indeterminate archosauriform. Although three species of Tsylmosuchus have been named, they lack diagnostic traits and are probably not distinct from each other. In 2023, Tsylmosuchus was reinterpreted as a proterosuchid, specifically a member of the subfamily Chasmatosuchinae.
Vjushkovisaurus is an extinct genus of Middle Triassic archosauriform. It is known from the Anisian-aged Donguz Gorizont in Sol-Iletsk, Orenburg Oblast, Russia. The genus was named in 1982, with the type species being V. berdjanensis. Material has been collected in the Berdyanka II locality from a fossil assemblage called the Eryosuchus Fauna along the Berdyanka River, specifically in a sand-carbonate concretion in the upper part of the main river channel. Vjushkovisaurus is known only from the holotype PIN 2865/62, a partial postcranial skeleton which consists of 12 presacral vertebrae, left humerus, ribs, a fragment of the coracoid and a fragment of the fibula.
Tikisuchus is an extinct genus of rauisuchid archosauromorph. It is known from the Late Triassic Tiki Formation in the Shahdol District of central India and was the first rauisuchid to have been found in Asia. The horizon from which remains have been found is Carnian in age. The type species is T. romeri, named in honor of American paleontologist Alfred Romer. Romer was present at the Tiki locality during the excavation of the fossil, but died before the description of the genus in 1987. Tikisuchus is known only from one specimen, called ISI R 305, which consists of the skull and some postcranial elements of a young individual.
Poposauroidea is a clade of advanced pseudosuchians. It includes poposaurids, shuvosaurids, ctenosauriscids, and other unusual pseudosuchians such as Qianosuchus and Lotosaurus. It excludes most large predatory quadrupedal "rauisuchians" such as rauisuchids and "prestosuchids". Those reptiles are now allied with crocodylomorphs in a clade known as Loricata, which is the sister taxon to the poposauroids in the clade Paracrocodylomorpha. Although it was first formally defined in 2007, the name "Poposauroidea" has been used for many years. The group has been referred to as Poposauridae by some authors, although this name is often used more narrowly to refer to the family that includes Poposaurus and its close relatives.
Decuriasuchus is an extinct genus of loricatan from the Middle Triassic period. It is a carnivorous archosaur that lived in what is now southern Brazil, in Paleorrota. It was first named by Marco Aurélio G. França, Jorge Ferigolo and Max C. Langer in 2011 and the type species is Decuriasuchus quartacolonia. The generic name means "unit of ten crocodiles" in Latin and Greek in reference to the ten known specimens and the animal's possible group behavior. The specific name refers to the Quarta Colonia region where the fossils were collected.
Smok is an extinct genus of large carnivorous archosaur. It lived during the latest Triassic period. Its remains have been found in Lisowice, southern Poland. The only species is Smok wawelski and was named in 2012. It is larger than any other known predatory archosaur from the Late Triassic or Early Jurassic of central Europe. The relation of Smok to other archosaurs has not yet been thoroughly studied; it may be a rauisuchid, prestosuchid, an ornithosuchid pseudosuchian or a theropod dinosaur.
Coelodontognathus is an extinct genus of reptile from the Early Triassic of European Russia. It was originally described as a procolophonid parareptile in 1967 but was reclassified as a possible trilophosaurid archosauromorph in 2008. The genus includes two species: the type species C. donensis and C. ricovi. C. donensis is known from the holotype PIN 4173/129 and the referred PIN 4173/130, and C. ricovi is known from the holotype PIN 4173/127 and the referred PIN 4173/128, all of which represent dentaries that are housed at the Paleontological Institute, Russian Academy of Sciences. Another dentary, SGU 104/3105, originally referred to C. donensis was reassigned to its own genus and species Vitalia grata by Ivakhnenko, 1973. The fossils have been found at the Donskaya Luka Locality near the village of Sirotinskaya and the Don River in Ilovlinsky District, Volgograd Oblast, from the Lipovskaya Formation of the Gamskii Horizon. Like Coelodontognathus, Vitalia which is known from the same locality was also first identified as a procolophonid and later reclassified as a trilophosaurid. Coelodontognathus and Vitalia are similar to procolophonids in that they have wide teeth but differs from them in that they have tooth roots set deep into the jaws.
Doniceps is an extinct genus of reptile from the Early Triassic of European Russia known from the type species D. lipovensis. It was solely known from the holotype premaxilla 104/3106 housed at Saratov University, however the specimen is probably lost. It was collected at the Donskaya Luka Locality near the village of Sirotinskaya in Ilovlinsky District, Volgograd Oblast, from the Lipovskaya Formation of the Gamskii Horizon. The generic name refers to the nearby Don River added the Greek suffix for "head", -ceps. The specific name is derived from the name of the type locality Donskaya Luka, also known as Lipovaya Balka. Named by Otschev and Rykov in 1968 as an archosauromorph, Arkhangelskii & Sennikov (2008) classified the taxon as a possible trilophosaurid. Doniceps is thought to be similar to Coelodontognathus and Vitalia, both of which are known exclusively from the same locality and were first identified as procolophonids but later reclassified as trilophosaurids.
Vitalia is an extinct genus of reptile from the Early Triassic of European Russia known from the type species V. grata. It is known from the holotype dentary PIN 4173/126 as well as two additional dentaries PIN 1043/627 and 1043/628, all housed at the Paleontological Institute, Russian Academy of Sciences. The type dentary was originally included in the hypodigm of Coelodontognathus donensis named by the notable Russian vertebrate paleontologist Vitaliy Georgiyevich Ochev in 1967. Ivakhnenko (1973) separated the specimen and gave it its own genus and species name in light of the new material, which he named in honor of Ochev. The dentaries of Vitalia were collected at the Donskaya Luka Locality near the village of Sirotinskaya in Ilovlinsky District, Volgograd Oblast, from the Lipovskaya Formation of the Gamskii Horizon. Like Coelodontognathus, Vitalia was originally described as a procolophonid parareptile in 1973, but Arkhangelskii & Sennikov (2008) reclassified the taxon as a possible trilophosaurid archosauromorph. Vitalia is thought to be similar to the possible trilophosaurids Coelodontognathus and Doniceps, both of which are known exclusively from the same locality. Coelodontognathus and Vitalia are similar to procolophonids in that they have wide teeth but differs from them in that they have tooth roots set deep into the jaws.
Scolotosuchus is an extinct genus of rauisuchid from the Early Triassic of Russia. The only known species, Scolotosuchus basileus, has been discovered at the Donskaya Luka Locality. It differs from all other rauisuchids in the morphology of its spine, which allowed it to both resist great stress and gave it a great range of mobility. Additionally, it may have lacked osteoderms, with its spine instead being supported in a similar manner as in dinosaurs. At 3 m (9.8 ft) it was likely the apex predator of its ecosystem.
