Phylum Chordata Bateson, 1885 - chordates
   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 Pelecani Sharpe, 1891 see Infraorder Pelecanides Sharpe, 1891
           3 Suborder Fregatae Sharpe see Infraorder Fregatides Sharpe, 1891