Vertebrata Cuvier, 1812 - vertebrates
   Gnathostomata
     Teleostomi
       Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988]
         Amniota Haeckel, 1866 [Gauthier, Kluge & Rowe 1988] - amniotes
           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 Cuculiformes Wagler, 1830 - cuckoos and plantain-eaters
                 02 Order Falconiformes Sharpe, 1874
                 03 Order Galliformes Temminck, 1820 - fowl
                 04 Order Columbiformes Latham, 1790 - pigeons and allies
                 05 Order Psittaciformes Wagler, 1830 [monotypic] - parrots
                 06 Family †Zygodactylidae Brodkorb, 1971
                 07 Order Coliiformes Murie, 1872 [monotypic] - mousebirds
                 08 Order Coraciiformes Forbes, 1884 - rollerlike birds
                 09 Order Strigiformes Wagler, 1830 - owls
                 10 Order Caprimulgiformes Ridgway, 1881 - nightjars
                 11 Order Apodiformes Peters, 1940 - swifts
                 12 Order Bucerotiformes Fürbringer, 1888 see Infraorder Bucerotides Fürbringer, 1888
                 13 Order Piciformes Meyer & Wolf, 1810 - scansorial birds
                 14 Order Passeriformes Linnaeus, 1758
                 15 Order Gruiformes Bonaparte, 1854
                 16 Order Podicipediformes Fürbringer, 1888 [monotypic]
                 17 Order †Diatrymiformes Shufeldt, 1913 [monotypic]
                 18 Order Charadriiformes Huxley, 1867 - shorebirds, gulls, auks
                 19 Order Anseriformes Wagler, 1831 - waterfowl and screamers
                 20 Order Ciconiiformes Bonaparte, 1854
                 21 Order Pelecaniformes Sharpe, 1891
                 22 Order Procellariiformes Fürbringer, 1888
                 23 Order Gaviiformes Wetmore & Miller, 1926 [monotypic]
                 24 Order Sphenisciformes Sharpe, 1891 [monotypic]