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 Pelecaniformes Sharpe, 1891
                     1 Family Phaethontidae Brandt, 1831 - tropicbirds
                     2 Family Pelecanidae Rafinesque, 1815 - pelicans
                     3 Family Sulidae Reichenbach, 1849 - gannets, boobies
                     4 Family Phalacrocoracidae Reichenbach, 1850 - cormorants
                     5 Family Anhingidae Reichenbach, 1849 - anhingas
                     6 Family Fregatidae Degland & Gerbe, 1867 - frigatebirds