''Archaeocyon'' ("ancient dog") is an extinct genus of the Borophaginae subfamily of

canid Canidae (; from Latin, ''canis'', "dog") is a family (biology), biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamily, subfamilies: the Caninae, a ...

s native to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It lived during the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

epoch 32-24 Ma., existing for approximately . Species of ''Archaeocyon'' are among the earliest known borophagines, although a species of '' Otarocyon'' has a slightly earlier first appearance. Fossils have been found across the northern Great Plains and along the west coast of North America. Archaeocyon head restoration

''Archaeocyon'' was a comparatively small and unspecialized dog. Its

dentition Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...

(teeth) suggests a slightly more hypocarnivorous (

omnivorous An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...

) diet than the otherwise similar '' Hesperocyon''. The skeleton is also generalized, lacking specializations for running and retaining a

plantigrade 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. ...

foot posture. A few derived features of the dentition support a relationship to Borophaginae and

Caninae Caninae (whose members are known as canines () is the only living subfamily within Canidae, alongside the extinct Borophaginae and Hesperocyoninae. They first appeared in North America, during the Oligocene around 35 million years ago, subsequent ...

(the subfamily that includes living canids), rather than to the basal canid subfamily Hesperocyoninae. The temporal position of ''Archaeocyon'' suggests an affinity to borophagines because the first members of Caninae appear substantially earlier.Wang, X., R.H. Tedford, and B.E. Taylor. 1999
Phylogenetic systematics of the Borophaginae (Carnivora, Canidae)
Bulletin of the American Museum of Natural History, 243:1-391.

Species

Three species of ''Archaeocyon'' have been described. The two earlier species, ''A. pavidus'' and ''A. leptodus'', differ primarily in size, with ''A. leptodus'' being larger. The third species, ''A. falkenbachi'', is the size of ''A. leptodus'' and differs from other ''Archaeocyon'' species in having a shorter, broader

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

References

{{Taxonbar, from=Q979764 Borophagines Oligocene canids Oligocene mammals of North America Prehistoric carnivoran genera Fossil taxa described in 1999