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
               1 Family †Ambiortidae Kurochkin, 1982
               2 Superorder †Odontognathae Wetmore, 1930 see Subclass Archaeornithes Gadow, 1893
               3 Order †Gobipterygiformes Elzanowski, 1974 [monotypic] see Order Alexornithiformes Brodkorb, 1976
               4 Order †Enantiornithiformes Martin, 1983 see Order Alexornithiformes Brodkorb, 1976
               5 Superorder Palaeognathae Pycraft, 1900 see Cohort Palaeognathae Pycraft, 1900
               6 Superorder Neognathae Pycraft, 1900 see Cohort Neognathae Pycraft, 1900