Desmatodon
Encyclopedia
Desmatodon is an extinct genus
of diadectid reptiliomorph. With fossils found from the Late Carboniferous of Pennsylvania
, Colorado
, and New Mexico
in the United States
, Desmatodon is the oldest known diadectid. Two species are currently recognized: the type species
D. hollandi and the species D. hesperis.
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.
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 diadectid reptiliomorph. With fossils found from the Late Carboniferous of Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Desmatodon is the oldest known diadectid. Two species are currently recognized: 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...
D. hollandi and the species D. hesperis.
Description
Remains of Desmatodon have been found from the Red Knob Formation of Pennsylvania, the Sangre de Cristo Formation in Colorado, and the Cutler FormationCutler Formation
The Cutler is a rock unit that is spread across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian stage. In Arizona and Utah it is often called the Cutler Group but the preferred USGS name is Cutler...
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.