Phylum [Vertebrata] (Lamarck, 1801)
   Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
     1 Subclass †Archaeornithes Gadow, 1893 see Superorder Archaeornithes Gadow, 1893
     2 Subclass †Enantiornithes Walker, 1981 see Infraclass Enantiornithes Walker, 1981
     3 Subclass †Odontornithes (Marsh, 1873)
     4 Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893