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 Anseriformes Wagler, 1831 - waterfowl and screamers
           Family Anatidae Vigors, 1825 - ducks, geese, swans
             Subfamily Anatinae Vigors, 1825 - pond ducks
               Genus Tadorna Boie, 1822
                 1 Tadorna ferruginea (Pallas, 1764) - ruddy shelduck
                 2 Tadorna cana (Gmelin, 1789) - South African shelduck
                 3 Tadorna variegata (Gmelin, 1789) - paradise shelduck
                 4 Tadorna tadornoides (Jardine & Selby, 1828) - Australian shelduck
                 5 Tadorna tadorna (Linnaeus, 1758) - common shelduck
                 6 Tadorna radjah (Lesson, 1828) - radjah shelduck
                 7 ‡Tadorna cristata (Kuroda, 1917) - crested shelduck