Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Order Carnivora Bowdich, 1821 - carnivores
       Suborder Caniformia Kretzoi, 1943
         Family Phocidae Gray, 1821 - true seals
           Genus Mirounga Gray, 1827 - elephant-seals
             Mirounga angustirostris (Gill, 1866) - northern elephant seal