Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
   Subclass Ornithurae Haeckel, 1866 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991}
     Infraclass Carinatae Merrem, 1813 see Clade Carinatae Merrem 1813 [Gauthier & de Queiroz 2001]
       Order Pelecaniformes Sharpe, 1891
         Suborder Pelecani Sharpe, 1891 see Infraorder Pelecanides Sharpe, 1891
           Family Pelecanidae Rafinesque, 1815 - pelicans
             1 Genus Pelecanus Linnaeus, 1758
             2 Genus †Liptornis Ameghino, 1895