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 Sphenisciformes Sharpe, 1891
           Family Spheniscidae Bonaparte, 1831 - penguins
             Genus Aptenodytes Miller, 1778
               1 Aptenodytes patagonicus Miller, 1778 - king penguin
               2 Aptenodytes forsteri Gray, 1844 - emperor penguin