Phytosaurs are an extinct group of large, mostly semiaquatic Late Triassic archosauriform reptiles. Phytosaurs belong to the order Phytosauria. Phytosauria and Phytosauridae are often considered to be equivalent groupings containing the same species, but some studies have identified non-phytosaurid phytosaurians. Phytosaurs were long-snouted and heavily armoured, bearing a remarkable resemblance to modern crocodilians in size, appearance, and lifestyle, as an example of convergence or parallel evolution. The name "phytosaur" means "plant reptile", as the first fossils of phytosaurs were mistakenly thought to belong to plant eaters.
Paleorhinus is an extinct genus of widespread basal phytosaur known from the Late Triassic. The genus was named in 1904 based on the type species Paleorhinus bransoni, which is known from Wyoming and Texas in the United States. Another valid species, Paleorhinus angustifrons from Bavaria, Germany, is also commonly referred to the genus. Paleorhinus had a length of about 2.5 meters.
Parasuchus is an extinct genus of basal phytosaur known from the Late Triassic of Andhra Pradesh and Madhya Pradesh, India. At its most restricted definition, Parasuchus contains a single species, Parasuchus hislopi. Parasuchus hislopi is one of several species belonging to a basal grade of phytosaurs, typified by the genus Paleorhinus. Historically, Paleorhinus has been known from better-described fossils, and many species have been lumped into that genus. Parasuchus hislopi, despite being described earlier than Paleorhinus, was considered an undiagnostic chimera until new neotype fossils were described in the late 1970s. Parasuchus hislopi and the two unambiguously valid species of Paleorhinus are all closely related; some authors have historically described them all under the species Paleorhinus, while others place the two Paleorhinus species into Parasuchus according to the principle of priority.
Rutiodon is an extinct genus of mystriosuchine phytosaurs from the Late Triassic of the eastern United States. The type species of Rutiodon, Rutiodon carolinensis, encompasses a large number of skulls and assorted postcranial fossils discovered in the Cumnock Formation of North Carolina. Fossils referable to the species are also known from Pennsylvania, New Jersey, and Virginia. Rutiodon carolinensis is the most well-described species of phytosaur in eastern North America, though its validity as a natural taxon has been questioned. Some paleontologists also recognize a larger and more robust species, Rutiodon manhattanensis, which is known from teeth and postcranial fossils from New Jersey and Pennsylvania.
Phytosaurus is a dubious genus of extinct parasuchid phytosaur found in an outcrop of the Keuper in Germany. Phytosaurus was the first phytosaur to be described, being done so by Georg Friedrich von Jaeger in 1828. The type species is P. cylindricodon and a second species, P. cubicodon, is also known.
Redondasaurus is an extinct genus of phytosaur from the Late Triassic of the southwestern United States. It was named by Hunt & Lucas in 1993, and contains two species, R. gregorii and R. bermani. It is the youngest and most evolutionarily-advanced of the phytosaurs.
Angistorhinus is an extinct genus of phytosaur known from the Late Triassic period of Texas and Wyoming, United States. It was first named by Mehl in 1913 and the type species is Angistorhinus grandis. Other species from Texas and Wyoming, A. alticephalus, A. gracilis and A. maximus, are cospecific with the type species. Angistorhinus is known from the holotype UC 631, partial skull and lower jaws recovered from the Popo Agie Formation, Chugwater Group, Wyoming and from the associated paratype UM 531, a partial skull, TMM 31098-1, skull and lower jaws and ROM 7977, partial skull and lower jaws, recovered from the 'Pre-Tecovas Horizon' in the Dockum Group, Texas. A possible second species, A. talainti is known from the Triassic of Morocco. In 1995, Long and Murry created the new combination, Angistorhinus megalodon by synonymy for Brachysuchus. Hungerbühler and Sues (2001) hypothesised that Angistorhinus is a junior synonym of Rutiodon. However, in 2010 Michelle R. Stocker retained the validity of Brachysuchus and of A. grandis.
Mystriosuchus is an extinct genus of phytosaur that lived in the Late Triassic in Europe and Greenland. It was first named by Eberhard Fraas in 1896, and includes four species: M. planirostris, M. westphali, M. steinbergeri, and M. alleroq.
Smilosuchus is an extinct genus of leptosuchomorph parasuchid from the Late Triassic of North America.
Mystriosuchini, historically known as Pseudopalatinae, is an extinct tribe of derived phytosaurs in the clade Leptosuchomorpha. As with all other phytosaurs, mystriosuchins lived during Late Triassic. The name is derived from the genus Mystriosuchus.
Leptosuchus is an extinct genus of leptosuchomorph phytosaur with a complex taxonomical history. Fossils have been found from the Dockum Group and lower Chinle Formation outcropping in Texas, New Mexico, and Arizona, USA, and date back to the Carnian stage of the Late Triassic.
Machaeroprosopus is an extinct genus of mystriosuchin leptosuchomorph phytosaur from the Late Triassic of the southwestern United States. M. validus, once thought to be the type species of Machaeroprosopus, was named in 1916 on the basis of three complete skulls from Chinle Formation, Arizona. The skulls have been lost since the 1950s, and a line drawing in the original 1916 description is the only visual record of the specimen. Another species, M. andersoni, was named in 1922 from New Mexico, and the species M. adamanensis, M. gregorii, M. lithodendrorum, M. tenuis, and M. zunii were named in 1930. Most species have been reassigned to the genera Smilosuchus, Rutiodon, or Phytosaurus. Until recently, M. validus was considered to be the only species that has not been reassigned. Thus, Machaeroprosopus was considered to be a nomen dubium or "doubtful name" because of the lack of diagnostic specimens that can support its distinction from other phytosaur genera. However, a taxonomic revision of Machaeroprosopus, conducted by Parker et al. in 2013, revealed that UW 3807, the holotype of M. validus, is not the holotype of Machaeroprosopus, while the species Machaeroprosopus buceros, Machaeroprosopus being a replacement name, with a fixed type species, for Metarhinus, is the combinatio nova of the type species of the genu: Belodon buceros. Therefore, the name Pseudopalatus must be considered a junior synonym of Machaeroprosopus, and all species of the former must be reassigned to the latter. This revised taxonomy was already accepted in several studies, including Stocker and Butler (2013). Stocker and Butler (2013) also treated M. andersoni as a valid species, and not a junior synonym of Machaeroprosopus buceros as was previously suggested by Long and Murry (1995).
Pravusuchus is an extinct genus of leptosuchomorph parasuchid phytosaur known from the Late Triassic of Arizona, United States. It contains a single species, Pravusuchus hortus, which is known from three specimens. These specimens were previously referred to Smilosuchus or to Leptosuchus, but Pravusuchus's autapomorphy, its phylogenetic position as well as a trait shared with mystriosuchins, justified the erection of a new taxon for the material.
Brachysuchus is an extinct genus of phytosaur known from the late Triassic period of Dockum Group in Texas, United States. It is known from the holotype UMMP 10336 is composed of a skull, lower jaws and partial postcranium and from the associated paratype UMMP 14366, nearly complete skull, recovered from the 'Pre-Tecovas Horizon' in the Dockum Group. It was first named by Case in 1929 and the type species is Brachysuchus megalodon. Its closest relative was Angistorhinus. However, its rostral crest was much smaller than that of Angistorhinus, and the rostrum as a whole is shorter and thicker.
Francosuchus is a dubious genus of probably basal phytosaur known from the Late Triassic of Bavaria, southern Germany. It was named by Oskar Kuhn in 1933 and the type species is Francosuchus broilii. In the same article Kuhn also named a second species Francosuchus latus. Both species were known solely from their holotypes, two partial skulls that were housed at the Bavarian State Collection for Palaeontogy and Geology. Both specimens were collected at Ebrach Quarry, bed number 13 from the late Carnian-aged Blasensandstein Member of the Hassberge Formation. As the holotypes were destroyed during World War II and poorly documented, Francosuchus and its species are usually considered to be nomina dubia.
Mesorhinosuchus is an extinct genus of basal phytosaur possibly known from the Early Triassic of Saxony-Anhalt, central-eastern Germany. It was first named by Otto Jaekel in 1910 and the type species is Mesorhinus fraasi. The generic name Mesorhinus was preoccupied by Mesorhinus piramydatus Ameghino, 1885, a macraucheniid mammal, which is now considered to be a junior synonym of Oxyodontherium. Thus, an alternative generic name, Mesorhinosuchus, was proposed by Oskar Kuhn in 1961. The genus is occasionally misspelled as Mesorhinosaurus, while Stocker and Butler (2013) recently misspelled its original generic name as Mesosuchus.
Protome is an extinct genus of parasuchid phytosaur from the Late Triassic of Arizona, represented by a single species, Protome batalaria. It is known from a single holotype incomplete, partially disarticulated skull and left lower jaw called PEFO 34034 from the Upper Lot's Wife beds, Sonsela Member of the Chinle Formation in Petrified Forest National Park. The skull was discovered in 2004 by Michelle Stocker and Bill Parker and was described by them as a specimen of Smilosuchus adamanensis. It was placed in the new genus Protome in 2012. The genus name Protome is the Greek word for an animal's face. The specific name batalaria is the Latin word for battleship, which is a reference to Battleship NW, the locality within Petrified Forest where the skull was found.
Parasuchidae is a clade of phytosaurs more derived than Diandongosuchus, a basal phytosaur. It encompasses nearly all phytosaurs, include early Parasuchus-grade forms as well as a more restricted clade of more specialized phytosaurs. This more restricted clade is traditionally known as the family Phytosauridae and more recently as the subfamily Mystriosuchinae.
Diandongosuchus is an extinct genus of archosauriform reptile, possibly a member of the Phytosauria, known from the Middle Triassic of China. The type species Diandongosuchus fuyuanensis was named in 2012 from the Zhuganpo Formation of Yunnan Province. It is a marine species that shows similarities with another Chinese Triassic species called Qianosuchus mixtus, although it has fewer adaptations toward marine life. It was originally classified as the basal-most member of the pseudosuchian clade Poposauroidea. However, a subsequent study conducted by Stocker et al. indicated it to be the basalmost known phytosaur instead.
Wannia is an extinct genus of basal phytosaur reptile known from the Late Triassic of Texas, southern United States. It contains a single species, Wannia scurriensis, which is known from a single specimen. This species was originally named as a species referred to Paleorhinus and later was considered as a possible junior synonym of Paleorhinus bransoni. However its re-description revealed five autapomorphies, and a phylogenetic position as the most basal known phytosaur, justifying the erection of a new generic name for the species.
