Heterodontosuchus is a dubious

Nomen dubium

In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...

 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 extinct 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...

. The genus was first described from a fragmentary anterior section of the mandible found from the Henry Mountains

Henry Mountains

The Henry Mountains are located in the southeastern portion of the U.S. state of Utah and run in a generally north-south direction, extending over a distance of about 30 miles . They were named by John Wesley Powell in honour of Joseph Henry, the first secretary of the Smithsonian Institution. The...

 in southeastern Utah

Utah

Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

. More fossils were later found from Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

. The name Heterodontosuchus refers to the difference in size between anterior and posterior teeth on this mandible. The teeth were compressed antero-posteriorly spaced closely together. The genus is now thought to be synonymous

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 with Nicrosaurus

Nicrosaurus

Nicrosaurus is an extinct genus of phytosaur reptile. Although it looked and probably lived like a crocodile, it was not closely related to these creatures, instead being a good example of parallel evolution...

, and the type and only species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, H. ganei, is regarded as a nomen dubium due the fragmentary nature of the remains associated with it.