Class Mammalia Linnaeus, 1758 - mammals
   Order Artiodactyla Owen, 1848 - even-toed ungulates see Order Cetartiodactyla Montgelard, Catzeflis & Douzery, 1997
     Family Bovidae Gray, 1821 - antelope, cattle, bison, buffalo, goats, and sheep
       Subfamily Caprinae Gray, 1821
         Genus Ovis Linnaeus, 1758 - sheep
           1 Ovis ammon (C. Linnaeus, 1758) - argali
           2 Ovis aries Linnaeus, 1758 - domestic sheep
           3 Ovis canadensis Shaw, 1804 - American bighorn
           4 Ovis dalli Nelson, 1884 - Dall sheep
           5 Ovis nivicola Eschscholtz, 1829 - Siberian bighorn
           6 Ovis vignei Blyth, 1841 - urial