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 Neognathae Pycraft, 1900 see Cohort Neognathae Pycraft, 1900
                 Order Galliformes Temminck, 1820 - fowl
                   1 Family Cracidae Vigors, 1825 - chachalacas, curassows, guans
                   2 Family Megapodiidae Lesson, 1831 - megapodes
                   3 Family Numididae Reichenbach, 1850 - guineafowl see Subfamily Numidinae Reichenbach, 1850
                   4 Family Phasianidae Vigors, 1825 - turkeys, grouse, pheasants, partridges
                   5 ?Family Turnicidae Gray, 1840 - buttonquails