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 Palaeognathae Pycraft, 1900 see Cohort Palaeognathae Pycraft, 1900
                 Order ‡Aepyornithiformes Newton, 1884 [monotypic]
                   Family ‡Aepyornithidae Bonaparte, 1853 - elephant birds