Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
               Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
                 Order Anseriformes Wagler, 1831 - waterfowl and screamers
                   Family Anatidae Vigors, 1825 - ducks, geese, swans
                     Subfamily Anserinae Vigors, 1825 - geese
                       Tribe Anserini Vigors, 1825 - geese see Subfamily Anserinae Vigors, 1825
                         Genus Cygnus Bechstein, 1803 - mute swan
                           1 Cygnus olor (Gmelin, 1789) - mute swan
                           2 Cygnus cygnus (Linnaeus, 1758) - whooper swan
                           3 Cygnus columbianus (Ord, 1815) - tundra swan
                           4 Cygnus melanocoryphus (Molina, 1782) see Cygnus melancoryphus (Molina, 1782)
                           5 Cygnus atratus (Latham, 1790) - black swan