Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Superclass Homotherma
       Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
         1 Subclass †Sauriurae Haeckel, 1866 see Subclass Archaeornithes Gadow, 1893
         2 Subclass Ornithurae Haeckel, 1866 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991}