"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.
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.
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.
Pseudosuchia is one of two major divisions of Archosauria, including living crocodilians and all archosaurs more closely related to crocodilians than to birds. Pseudosuchians are also informally known as "crocodilian-line archosaurs". Despite Pseudosuchia meaning "false crocodiles", the name is a misnomer as true crocodilians are now defined as a subset of the group.
Rauisuchidae is a group of large predatory Triassic archosaurs. Some disagreement exists over which genera should be included in the Rauisuchidae and which should be in the related Prestosuchidae and Poposauridae, and indeed whether these should even be thought of as separate valid families. Rauisuchids occurred throughout much of the Triassic, and may have first occurred in the Early Triassic if some archosaurian taxa such as Scythosuchus and Tsylmosuchus are considered to be within the family.
Prestosuchidae is a polyphyletic grouping of carnivorous archosaurs that lived during the Triassic. They were large active terrestrial apex predators, ranging from around 2.5 to 7 metres in length. They succeeded the Erythrosuchidae as the largest archosaurs of their time. While resembling erythrosuchids in size and some features of the skull and skeleton, they were more advanced in their erect posture and crocodile-like ankle, indicating more efficient gait. "Prestosuchids" flourished throughout the whole of the middle, and the early part of the late Triassic, and fossils are so far known from Europe, India, Africa (Tanzania), Argentina, and Paleorrota in Brazil. However, for a long time experts disagree regarding the phylogenetic relationships of the group, what genera should be included, and whether indeed the "Prestosuchidae" constitute a distinct family.
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".
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.
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.
Arganasuchus is an extinct genus of "rauisuchian" (loricatan) archosaur. It is known from a single species, Arganasuchus dutuiti. Fossils of this genus have been found in Upper Triassic rocks of the Argana Basin, Morocco. Though its remains were initially referred to Ticinosuchus when discovered during the 1970s, in 2007 it was identified as a distinct genus with unique features of the pubis and maxilla. Arganasuchus also had several anatomical details in common with Batrachotomus, Fasolasuchus, and Postosuchus, though its relations with other loricatans remains unresolved. Arganasuchus is considered a carnivore due to its large, knife-shaped teeth.
The Popo Agie Formation is a Triassic geologic formation that crops out in western Wyoming, western Colorado, and Utah. It was deposited during the Late Triassic in fluvial (river) and lacustrine (lake) environments that existed across much of what is now the American southwest. Fragmentary fossils of prehistoric reptiles and amphibians, including pseudosuchian reptiles and temnospondyl amphibians, have been discovered in the Popo Agie Formation. Dinosaur remains are also among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.
Procerosuchus is an extinct genus of loricatan archosaur. Fossils have been collected from the Late Triassic Santa Maria Formation in Geopark of Paleorrota, Rio Grande do Sul, Brazil, which is Carnian in age. The genus was first described by the German paleontologist Friedrich von Huene in 1942.
Stagonosuchus is an extinct genus of loricatan, or possibly a species of Prestosuchus. Fossils have been found from the Late Triassic Manda Formation in Tanzania that are Anisian in age.
Loricata is a clade of archosaur reptiles that includes crocodilians and some of their Triassic relatives, such as Postosuchus and Prestosuchus. More specifically, Loricata includes Crocodylomorpha and most "rauisuchians", a paraphyletic grade of large terrestrial pseudosuchians which were alive in the Triassic period and ancestral to crocodylomorphs.
Youngosuchus is an extinct genus of archosaur from the Middle Triassic of China. The type species is Y. sinensis. Y. sinensis was first described in 1973 as a new species of the erythrosuchid Vjushkovia. In 1985, it was reassigned as its own genus of rauisuchid. A 1992 study supported the original classification of Youngosuchus sinensis as an erythrosuchid, but more recent studies classify it as a "rauisuchian"-grade loricatan archosaur completely unrelated to Vjushkovia, which is most likely a synonym of Garjainia.
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.
Paracrocodylomorpha is a clade of pseudosuchian archosaurs. The clade includes the diverse and unusual group Poposauroidea as well as the generally carnivorous and quadrupedal members of Loricata, including modern crocodylians. Paracrocodylomorpha was named by paleontologist J. Michael Parrish in 1993, although the group is now considered to encompass more reptiles than his original definition intended. The most recent definition of Paracrocodylomorpha, as defined by Sterling Nesbitt in 2011, is "the least inclusive clade containing Poposaurus and Crocodylus niloticus. Most groups of paracrocodylomorphs became extinct at the end of the Triassic period, with the exception of the crocodylomorphs, from which crocodylians such as crocodiles and alligators evolved in the latter part of the Mesozoic.
Vivaron is a genus of rauisuchid known from the Late Triassic Chinle Formation in New Mexico. It is the second rauisuchid known from the southwestern United States, and it highlights the wide biogeographic range similar rauisuchid taxa occupied during the Late Triassic across Pangaea, despite the varied faunal assemblages at different latitudes.
Etjosuchus is an extinct genus of "rauisuchian" (loricatan) archosaur from the Triassic of Namibia. It is known from a single species, Etjosuchus recurvidens, which is based on a partial skeleton from the Ladinian or Carnian-age Omingonde Formation.
