Class [Mammalia] Linnaeus, 1758 - mammals
   Order Pinnipedia Illiger, 1811 - seals, sea lions, and walrus see Parvorder Pinnipedia Illiger, 1811
     Family Phocidae Gray, 1821 - true seals
       Genus Halichoerus Nilsson, 1820 - gray seal
         1 Halichoerus grypus (Fabricius, 1791) - gray seal