Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Order Carnivora Bowdich, 1821 - carnivores
       Suborder Caniformia Kretzoi, 1943
         Family Canidae Batsch, 1788 - dogs, wolves, coyotes, jackals, and foxes
           Genus Urocyon Baird, 1857 - grey foxes
             Urocyon cinereoargenteus (Schreber, 1775) - gray fox
               01 [Urocyon cinereoargenteus cinereoargenteus] (Schreber, 1775)
               02 Urocyon cinereoargenteus borealis Merriam, 1903
               03 Urocyon cinereoargenteus californicus Mearns, 1897
               04 Urocyon cinereoargenteus costaricensis Goodwin, 1938
               05 Urocyon cinereoargenteus floridanus Rhoads, 1895
               06 Urocyon cinereoargenteus fraterculus Elliot, 1896
               07 Urocyon cinereoargenteus furvus Allen & Barbour, 1923
               08 Urocyon cinereoargenteus guatemalae Miller, 1899
               09 Urocyon cinereoargenteus madrensis Burt & Hooper, 1941
               10 Urocyon cinereoargenteus nigrirostris (Lichtenstein, 1850)
               11 Urocyon cinereoargenteus ocythous Bangs, 1899
               12 Urocyon cinereoargenteus orinomus Goldman, 1938
               13 Urocyon cinereoargenteus peninsularis Huey, 1928
               14 Urocyon cinereoargenteus scottii Mearns, 1891
               15 Urocyon cinereoargenteus townsendi Merriam, 1899
               16 Urocyon cinereoargenteus venezuelae Allen, 1911