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 Sphenisciformes Sharpe, 1891
         Family Spheniscidae Bonaparte, 1831 - penguins
           Subfamily †Paraptenodytinae Simpson
             1 Genus †Paraptenodytes Ameghino, 1891
             2 Genus †Isotremornis Ameghino, 1905
             3 Genus †Pseudospheniscus Ameghino, 1905
             4 Genus †Neculus Ameghino, 1905, nom. dub.