Phylum Chordata Bateson, 1885 - chordates
   Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
     Subclass †Archaeornithes Gadow, 1893 see Superorder Archaeornithes Gadow, 1893
       1 Genus †Archaeopteryx Meyer, 1861
       2 Genus †Hesperornis Marsh, 1872
       3 Genus †Ichthyornis Marsh, 1872