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 Psittaciformes Wagler, 1830 - parrots
           Family Psittacidae Illiger, 1811 - cockatoos and parrots
             Subfamily Nymphicinae Astuti, 2004 see Subfamily Cacatuinae del Hoyo et al., 2014
               Genus Nymphicus Wagler, 1832
                 Nymphicus hollandicus (Kerr, 1792) - cockatiel