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 Pelecaniformes Sharpe, 1891
                   1 Suborder Phaethontes Sharpe, 1891
                   2 Suborder †Odontopterygia Spulski [monotypic] see Order Odontopterygiformes Spulski, 1910
                   3 Suborder Fregatae Sharpe [monotypic] see Infraorder Fregatides Sharpe, 1891
                   4 Suborder Pelecani Sharpe, 1891 [monotypic] see Infraorder Pelecanides Sharpe, 1891
                   5 Suborder Sulae Sharpe see Parvorder Sulida (Reichenbach, 1849) Sibley et al., 1988