''Oxetocyon'' ("beginning dog") is an extinct

monospecific In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus of the

Borophaginae The extinct Borophaginae form one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Hesperocyoninae and extant Caninae. Borophaginae, called "bone-crushing dogs", were endemic to North America dur ...

subfamily of

canid Canidae (; from Latin, '' canis'', " dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found withi ...

s native to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

. It lived during the Early

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but t ...

epoch, existing for approximately . Fossils have been found in

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...

and

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large po ...

. Fossils of ''Oxetocyon'' are rare and, as a result, the

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 nom ...

is poorly known, and only the

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, ...

, dentaries, and a fragmentary

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

have been reported. The teeth of ''Oxetocyon'' indicate a hypocarnivorous diet, as is found in the living

raccoon dog The common raccoon dog (''Nyctereutes procyonoides''), also called the Chinese or Asian raccoon dog, is a small, heavy-set, fox-like canid native to East Asia. Named for its raccoon-like face markings, it is most closely related to foxes. Common ...

, and suggest a potential relationship to the unusual borophagine ''

Otarocyon ''Otarocyon'' ("large eared dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Oligocene epoch, about 34—30 Ma (million years ago). Fossils have been found only in Montana, Wyoming ...

''. ''Oxetocyon'' is distinguished from ''Otarocyon'' by its own set of dental specializations for an omnivorous diet, particularly by the presence of a cleft that divides each upper molar into front and back halves.Xiaoming Wang, R.H. Tedford, and B.E. Taylor. 1999
Phylogenetic systematics of the Borophaginae
/ref>

References

Borophagines Oligocene carnivorans Paleogene mammals of North America Prehistoric carnivoran genera Fossil taxa described in 1954 {{canid-stub