organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Superclass Tetrapoda Goodrich, 1930 - tetrapods see Clade Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988]
               Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
                 Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
                   01 Order Tinamiformes Huxley, 1872
                   02 Order †Palaeocursornithiformes Kessler & Jurcsák, 1986
                   03 Order Struthioniformes Latham, 1790
                   04 Order Rheiformes Forbes, 1884 see Suborder Rheae Forbes, 1884
                   05 Order Casuariiformes Sclater, 1880
                   06 Order †Dinornithiformes Gadow, 1893 - moas
                   07 Order †Aepyornithiformes Newton, 1884
                   08 Order Apterygiformes Haeckel, 1866
                   09 Order Galliformes Temminck, 1820 - fowl
                   10 Order Anseriformes Wagler, 1831 - waterfowl and screamers
                   11 Order Strigiformes Wagler, 1830 - owls
                   12 Order Coraciiformes Forbes, 1884 - rollerlike birds
                   13 Order †Sandcoleiformes Houde & Olson, 1992
                   14 Order Coliiformes Murie, 1872 - mousebirds
                   15 Order Piciformes Meyer & Wolf, 1810 - scansorial birds
                   16 Order Passeriformes Linnaeus, 1758
                   17 Order Apodiformes Peters, 1940 - swifts
                   18 Order Caprimulgiformes Ridgway, 1881 - nightjars
                   19 Order Trogoniformes Wetmore & Miller, 1926 - trogons
                   20 Order Cuculiformes Wagler, 1830 - cuckoos and plantain-eaters
                   21 Order Psittaciformes Wagler, 1830 - parrots
                   22 Order †Diatrymiformes Shufeldt, 1913
                   23 Order Gruiformes Bonaparte, 1854
                   24 Order Charadriiformes Huxley, 1867 - shorebirds, gulls, auks
                   25 Order Columbiformes Latham, 1790 - pigeons and allies
                   26 Order Falconiformes Sharpe, 1874
                   27 Order Ciconiiformes Bonaparte, 1854
                   28 Order Podicipediformes Fürbringer, 1888
                   29 Order Pelecaniformes Sharpe, 1891
                   30 Order Procellariiformes Fürbringer, 1888
                   31 Order Sphenisciformes Sharpe, 1891
                   32 Order Gaviiformes Wetmore & Miller, 1926