Neornithes Gadow, 1893 - living birds
   Neognathae Pycraft 1900 see Cohort Neognathae Pycraft, 1900
     Galloanserae Sibley, Ahlquist & Monroe Jr., 1988 see Subcohort Galloanserae Sibley, Ahlquist & Monroe Jr., 1988
       [Order] Anseriformes Wagler, 1831 - waterfowl and screamers
         Family Anatidae Vigors, 1825 - ducks, geese, swans
           Subfamily Anatinae Vigors, 1825 - pond ducks
             Genus Oxyura Bonaparte, 1828 - blue-billed duck
               1 Oxyura jamaicensis (Gmelin, 1789) - ruddy duck
               2 Oxyura ferruginea (Eyton, 1838) - Andean duck
               3 Oxyura vittata (Philippi, 1860) - lake duck
               4 Oxyura australis Gould, 1837 - blue-billed duck
               5 Oxyura maccoa (Eyton, 1838) - Maccoa duck
               6 Oxyura leucocephala (Scopoli, 1769) - white-headed duck