''Crosbysaurus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

archosauromorph that lived in the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, and

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

. It is known from the

Chinle Formation The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In Ne ...

and Dockum Group rock units from the southwestern United States. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

is ''C. harrisae'', and the only known material includes teeth. 11 specimens are known, each including a single tooth. ''Crosbysaurus'' was originally identified as an ornithischian dinosaur by Andrew Heckert when it was first described in 2004. Further work has shown that it is likely an archosauromorph based on the features of its teeth, and it may belong to Archosauriformes. The taxon is likely valid as it differs from other genera from the same region known from teeth like '' Revueltosaurus'', '' Tecovasaurus'', ''

Krzyzanowskisaurus ''Krzyzanowskisaurus'' (meaning "Stan Krzyżanowski's lizard") is the name given to a genus of archosaur from the Late Triassic-aged Chinle Formation and it is a tooth taxon, based on fossils only of teeth (such as the holotype tooth NMMNH P-29 ...

'', ''

Lucianosaurus ''Lucianosaurus'' is an extinct genus of amniote of unknown affinities, known only from teeth. Initially described as a basal ornithischian dinosaur, subsequently reclassified as a member of the clade Archosauriformes of uncertain phylogenetic ...

'', and '' Protecovasaurus''.

Description

The teeth of ''Crosbysaurus'' are triangular in outline with

serrations Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pr ...

on both edges. Almost all specimens have "compound denticles"; serrations with their own subdivisions. The serrations on the trailing (posterior/distal) edge of the tooth are always larger than the leading (anterior/mesial) edge. The teeth are small, approximately 3-5 millimeters tall. Owing to their blunt outline it is presumed that ''Crosbysaurus'' was a herbivore.

References

* https://translate.google.com/translate?hl=en&sl=de&u=http://simonkrauter.ntux.at/newdinorama/dinos/c/crosbysaurus/daten.htm&prev=/search%3Fq%3DCrosbysaurus%2B%26hl%3Den%26lr%3D%26sa%3DG Prehistoric archosauriforms Prehistoric reptile genera Late Triassic reptiles of North America Fossil taxa described in 2004 {{triassic-reptile-stub