Rhizocyon

Taxobox
name = "Rhizocyon"
fossil_range = early Oligocene
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Carnivora
familia = Canidae
subfamilia = †Borophaginae
genus = †"Rhizocyon"
genus_authority = Wang, Tedford, & Taylor, 1999
species = †"R. oregonensis"
binomial = †"Rhizocyon oregonensis"
binomial_authority = (Merriam, 1906)

"Rhizocyon" ("root dog") is an early member of the subfamily Borophaginae, an extinct subgroup of the family Canidae, which includes living dogs, wolves, and foxes. Only a single species, "R. oregonensis", is known and all fossils come from the early Oligocene (Arikareean NALMA) of the John Day Formation in Oregon. "Rhizocyon" was similar to a contemporary species, "Archaeocyon leptodus", from the Great Plains, but it shows a few subtle differences in the structure of the skull and dentition that indicate that "Rhizocyon" may be close to the ancestry of later borophagines.

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.