living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         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
                 Superorder Neognathae Pycraft, 1900 see Cohort Neognathae Pycraft, 1900
                   Order Charadriiformes Huxley, 1867 - shorebirds, gulls, auks
                     Family Alcidae Vigors, 1825 - auks
                       1 Genus Alca Linnaeus, 1758
                       2 Genus Cepphus Pallas, 1769
                       3 Genus Brachyramphus Brandt, 1837
                       4 Genus Aethia Merrem, 1788
                       5 Genus Fratercula Brisson, 1760
                       6 Genus Alle Link, 1806
                       7 Genus Uria Brisson, 1760
                       8 Genus ‡Pinguinus Bonnaterre, 1791