Archaeocyon

Taxobox
name = "Archaeocyon"
fossil_range = early to late Oligocene


image_caption = Skull of "Archaeocyon leptodus"
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Carnivora
familia = Canidae
subfamilia = †Borophaginae
genus = †"Archaeocyon"
genus_authority = Wang, Tedford, & Taylor, 1999
type_species = †"Pseudocynodictis pavidus"
subdivision_ranks = Species
subdivision =
* †"A. falkenbachi"
* †"A. leptodus"
* †"A. pavidus"

"Archaeocyon" ("beginning dog") is the most primitive genus in the subfamily Borophaginae, an extinct subgroup of the family Canidae, which includes living dogs, wolves, and foxes. Fossils of "Archaeocyon" are known from the Oligocene of the western United States, coming from rocks assigned to the Whitneyan and Arikareean NALMAs (Mya|32-24|mya). Species of "Archaeocyon" are among the earliest known borophagines, although a species of "Otarocyon" has a slightly earlier first appearance.

"Archaeocyon" was a comparatively small and unspecialized dog. Its dentition (teeth) suggests a slightly more hypocarnivorous (omnivorous) diet than the otherwise similar "Hesperocyon". The skeleton is also generalized, lacking specializations for running and retaining a plantigrade foot posture.

A few derived features of the dentition support a relationship to Borophaginae and Caninae (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.

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.

References:

*Wang, X., R.H. Tedford, and B.E. Taylor. 1999. [http://hdl.handle.net/2246/1588 Phylogenetic systematics of the Borophaginae (Carnivora, Canidae)] . Bulletin of the American Museum of Natural History, 243:1-391.