''Desmatodon'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of diadectid reptiliomorph. With fossils found from the

Kasimovian The Kasimovian is a geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian (late Carboniferous), lasting from to Ma.; 2004: ''A Geologic Time Scale 2004'', Cambridge Universi ...

(Missourian) stage of the

Late Carboniferous Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effe ...

Pennsylvania Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Ma ...

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

, and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

, ''Desmatodon'' is the oldest known diadectid. Two species are currently recognized: 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( ...

''D. hollandi'' and the species ''D. hesperis''.

Description

Remains of ''Desmatodon'' have been found from the

Glenshaw Formation The Glenshaw Formation is a mapped sedimentary bedrock unit in Pennsylvania, Maryland, West Virginia, and Ohio, of Pennsylvanian age. It is the lower of two formations in the Conemaugh Group, the upper being the Casselman Formation. The bound ...

of Pennsylvania, the

Sangre de Cristo Formation The Sangre de Cristo Formation is a geologic formation in Colorado and New Mexico. It preserves fossils dating back to the late Pennsylvanian to early Permian. Description The formation is divided into an informal lower member and an upper Crest ...

in Colorado, and the Cutler Formation of New Mexico. The genus is known mostly from teeth and portions of skulls. The cheek teeth are robust and spade-shaped with several cusps on their surfaces. The two species can be distinguished by the distribution of teeth in their jaws; ''D. hesperis'' has tightly packed teeth while ''D. hollandi'' has widely spaced teeth. In both species, the lower jaw is deep and possesses a ridge that may have aided in chewing plant material. Some specimens that are thought to belong to young individuals have fewer, more widely spaced teeth with no wear facets.

Paleobiology

Like most other diadectids, ''Desmatodon'' was a terrestrial herbivore that consumed high-fiber plants. Protruding incisiform teeth and a large digestive tract may have allowed the animal to effectively consume and digest plant material. Being the oldest diadectid, ''Desmatodon'' also is the oldest known herbivorous land vertebrate.

References

Diadectids Kasimovian genera Pennsylvanian tetrapods of North America Carboniferous Colorado Paleontology in Colorado Carboniferous geology of New Mexico Paleontology in New Mexico Carboniferous geology of Pennsylvania Paleontology in Pennsylvania Fossil taxa described in 1908 {{Carboniferous-animal-stub