Philotrox is an extinct monospecific genus of the Hesperocyoninae subfamily of early canids native to North America. It lived during the Oligocene, 30.8—26.3 Ma, existing for approximately . In form, it was intermediate between the small Cynodesmus and the later Enhydrocyon, the first hypercarnivorous, "bone-cracking", canid. References Wang, X. 1994. Phylogenetic systematics of the Hesperocyoninae (Carnivora, Canidae). Bulletin of the American Museum of Natural History, 221:1-207. Hesperocyonines Oligocene carnivorans Oligocene mammals of North America Prehistoric carnivoran genera Taxa named by John Campbell Merriam Rupelian genus first appearances Chattian genus extinctions