Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
   Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
     Infraclass Neoaves Sibley et al., 1988 see Subcohort Neoaves Sibley et al., 1988
       Parvclass Passerae see Superorder Passerimorphae Sibley et al., 1988
         Superorder Passerimorphae Sibley et al., 1988
           Order Ciconiiformes Bonaparte, 1854
             Suborder Charadrii Huxley, 1867 - shorebirds see Order Charadriiformes Huxley, 1867
               Infraorder Charadriides Huxley, 1867
                 Parvorder Charadriida see Superfamily Charadrioidea Vigors, 1825
                   Superfamily Charadrioidea Vigors, 1825
                     Family Charadriidae Vigors, 1825 - plovers
                       Subfamily Recurvirostrinae Bonaparte, 1831 - avocets and stilts
                         Tribe Haematopodini Gray, 1840 - oystercatchers see Family Haematopidae Bonaparte, 1838
                           Genus Haematopus Linnaeus, 1758
                             Haematopus unicolor Forster, 1844 - variable oystercatcher
                               Haematopus unicolor chathamensis Hartert, 1827 - Chatham Islands oystercatcher