Angistorhinus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of phytosaur

Phytosaur

Phytosaurs are an extinct group of large semi-aquatic Late Triassic archosaurs. Phytosaurs belong to the family Phytosauridae and the order Phytosauria. They were long-snouted and heavily armoured, bearing a remarkable resemblance to modern crocodiles in size, appearance, and lifestyle, an example...

 known from the Late Triassic

Late Triassic

The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...

 period of Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and Wyoming

Wyoming

Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

, USA. It was first named by Mehl in 1913

1913 in paleontology

-Dinosaurs:* A US Geological Survey crew headed by Eugene Stebinger and a US National Museum crew headed by Charles Gilmore worked together to excavate the first dinosaur discovery of the Two Medicine Formation.-Newly named dinosaurs:...

 and the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 is Angistorhinus grandis. Other species from Texas and Wyoming, A. alticephalus (Stovall and Wharton, 1936), A. gracilis (Mehl, 1915) and A. maximus (Mehl, 1928), are cospecific with the type species. Angistorhinus is known from the holotype UC 631, partial skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 and lower jaw

Jaw

The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...

s recovered from the Popo Agie Formation

Popo Agie Formation

The Popo Agie Formation is a Mesozoic geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.-See also:* List of dinosaur-bearing rock formations...

, Chugwater Group, Wyoming

Wyoming

Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

 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

Dockum Group

The Dockum is a Late Triassic geologic group found primarily on the Llano Estacado of western Texas and eastern New Mexico with minor exposures in southwestern Kansas, eastern Colorado, and Oklahoma panhandle. The Dockum reaches a maximum thickness of slightly over 650 m but is usually much...

, Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

. A possible second species, A. talainti is known from the Triassic

Triassic

The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

 of Morocco

Morocco

Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

. In 1995, Long and Murry created the new combination, Angistorhinus megalodon by synonymy for Brachysuchus

Brachysuchus

Brachysuchus is an extinct genus of phytosaur known from the late Triassic period of Dockum Group in Texas, USA. 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...

. Hungerbühler and Sues (2001) hypothesised that Angistorhinus is a junior synonym of Rutiodon

Rutiodon

Rutiodon is an extinct genus of archosaur belonging to the family Phytosauridae. It lived during the Late Triassic period, and was about 10 to 25 feet in length...

. However, in 2010 Michelle R. Stocker retained the validity of Brachysuchus

Brachysuchus

Brachysuchus is an extinct genus of phytosaur known from the late Triassic period of Dockum Group in Texas, USA. 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...

and of A. grandis.