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
                   01 Order Gaviiformes Wetmore & Miller, 1926
                   02 Order Podicipediformes Fürbringer, 1888
                   03 Order Procellariiformes Fürbringer, 1888
                   04 Order Pelecaniformes Sharpe, 1891
                   05 Order Ciconiiformes Bonaparte, 1854
                   06 Order Phoenicopteriformes Fürbringer, 1888 see Order Ciconiiformes Bonaparte, 1854
                   07 Order Anseriformes Wagler, 1831 - waterfowl and screamers
                   08 Order Falconiformes Sharpe, 1874
                   09 Order Galliformes Temminck, 1820 - fowl
                   10 Order Opisthocomiformes L'Herminer, 1837
                   11 Order Gruiformes Bonaparte, 1854
                   12 Order Charadriiformes Huxley, 1867 - shorebirds, gulls, auks
                   13 Order Columbiformes Latham, 1790 - pigeons and allies
                   14 Order Psittaciformes Wagler, 1830 - parrots
                   15 Order Cuculiformes Wagler, 1830 - cuckoos and plantain-eaters
                   16 Order Strigiformes Wagler, 1830 - owls
                   17 Order Caprimulgiformes Ridgway, 1881 - nightjars
                   18 Order Apodiformes Peters, 1940 - swifts
                   19 Order Coliiformes Murie, 1872 - mousebirds
                   20 Order Trogoniformes Wetmore & Miller, 1926 - trogons
                   21 Order Coraciiformes Forbes, 1884 - rollerlike birds
                   22 Order Piciformes Meyer & Wolf, 1810 - scansorial birds
                   23 Order Passeriformes Linnaeus, 1758