Mammalia Linnaeus, 1758 - mammals
   Theria Parker & Haswell, 1897
     Carnivora Bowdich, 1821 - carnivores
       Caniformia Kretzoi, 1943
         Canidae Batsch, 1788 - dogs, wolves, coyotes, jackals, and foxes
           Canis Linnaeus, 1758 - dogs, wolves, coyotes, and jackals
             Canis lupus Linnaeus, 1758 - wolf
               Canis lupus occidentalis Richardson, 1829