Class Mammalia Linnaeus, 1758 - mammals
   Order Carnivora Bowdich, 1821 - carnivores
     Family Ursidae Batsch, 1788 - bears
       Subfamily Ursinae Batsch, 1788
         Genus Ursus Linnaeus, 1758 - black, brown, polar, sun, and sloth bears
           1 Ursus americanus Pallas, 1780 - American black bear
           2 Ursus arctos Linnaeus, 1758 - brown bear
           3 Ursus maritimus Phipps, 1774 - polar bear
           4 Ursus thibetanus Cuvier, 1823 - Asian black bear