Ammorhynchus 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 hyperodapedontid rhynchosaur

Rhynchosaur

Rhynchosaurs were a group of Triassic diapsid reptiles related to the archosaurs.-Description:Rhynchosaurs were herbivores, and at times abundant , with stocky bodies and a powerful beak...

 from middle 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...

 (Anisian

Anisian

In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 245 million years ago until 237 million years ago, approximately...

 stage) deposits of Navajo County, 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...

. It is known from the holotype

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

 MSM 02-153/P4585, a nearly complete left maxilla

Maxilla

The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...

 and from three paratypes (MSM 00-99/P4409, MSM 00-103/P4586 and MSM 02-145/P4544) from the same locality. It was found in the Holbrook Member, upper Moenkopi Formation

Moenkopi Formation

The Moenkopi is a geological formation that is spread across the U.S. states of New Mexico, northern Arizona, Nevada, southeastern California, eastern Utah and western Colorado. This unit is considered to be a group in Arizona. Part of the Colorado Plateau and Basin and Range, this formation was...

 of northern Arizona. It was first named by S. J. Nesbitt and R. L. Whatley in 2004

2004 in paleontology

-New taxa:-newly named:-newly named:-New taxa:-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-New taxa:-Non-mammalian:...

 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 Ammorhynchus navajoi.