Phylum Chordata Bateson, 1885 - chordates
   Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
     Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
       Superorder Neognathae Pycraft, 1900 see Cohort Neognathae Pycraft, 1900
         Order Anseriformes Wagler, 1831 - waterfowl and screamers
           Family Anatidae Vigors, 1825 - ducks, geese, swans
             Subfamily Anatinae Vigors, 1825 - pond ducks
               Genus Somateria Leach, 1819
                 1 Somateria mollissima (Linnaeus, 1758) - common eider
                 2 Somateria spectabilis (Linnaeus, 1758) - king eider
                 3 Somateria fischeri (Brandt, 1847) - spectacled eider