Oligocene to Pliocene | regnum = Animalia | phylum = Chordata | classis = Mammalia | ordo = Carnivora | familia = Canidae | subfamilia = †Borophaginae | genus = | genus_authority = | subdivision_ranks = Genera | subdivision = See text }} The subfamily Borophaginae's an extinct group of canids that were endemic to North America, and lived from roughly 40 to 2.5 million years ago (Oligocene to Pliocene). The Borophaginae apparently descended from the subfamily Hesperocyoninae; they evolved… (More on Borophaginae)