''Archaeocyon'' ("ancient dog") is an extinct 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 du ...

subfamily of

canid Canidae (; from Latin, ''canis'', "dog") is a family (biology), 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 subfamily, ...

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 the C ...

. It lived during the

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 32-24 Ma., existing for approximately . Species of ''Archaeocyon'' are among the earliest known borophagines, although a species of ''

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, an ...

'' has a slightly earlier first appearance. Fossils have been found across the northern Great Plains and along the west coast of North America. ''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-physiolog ...

(teeth) suggests a slightly more hypocarnivorous (

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nu ...

) diet than the otherwise similar ''

Hesperocyon ''Hesperocyon'' is an extinct genus of canids (subfamily Hesperocyoninae, family Canidae) that was endemic to North America, ranging from southern Canada to Colorado. It appeared during the Uintan age, – Bridgerian age (NALMA) of the Mid- E ...

''. 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 The Caninae, known as canines, are one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Borophaginae and Hesperocyoninae. The Caninae includes all living canids and their most recent fossil rel ...

(the subfamily that includes living canids), rather than to the basal canid subfamily

Hesperocyoninae The extinct Hesperocyoninae are one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Borophaginae and extant Caninae. Taxonomic history Hesperocyoninae are basal canids that gave rise to the ...

. 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 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, t ...

References

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