[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Animalia Linnaeus, 1758 - animals
     Branch Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
       Division Bilateria Hatschek, 1888 see Subkingdom Bilateria Hatschek, 1888
         Subdivision Deuterostomia Grobben, 1908 see Infrakingdom Deuterostomia Grobben, 1908
           Phylum Chordata Bateson, 1885 - chordates
             Subphylum Vertebrata Cuvier, 1812 - vertebrates
               Superclass Tetrapoda Goodrich, 1930 - tetrapods see Clade Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988]
                 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
                         Family Opisthocomidae Swainson, 1837 - hoatzins
                           Genus Opisthocomus Illiger, 1811