Super-class

Class

Sub-class

Super-order

Order

Family

Sub-family

Tribe

Gnathostomata

Aves

Neornithes

Ratitae

(Paleognathae)

Struthioniformes

Struthionidae

Rheiformes

Rheidae

Casuariformes

Casuariidae

Dromaiidae

Apterygiformes

Apterygidae

Tinamiformes

Tinamidae

Impennae

Sphenisciformes

Spheniscidae

Carinatae

(Neognathae)

Podicipediformes

Podicipedidae

Procellariformes

Procellaridae

Diomedeidae

Hydrobatidae

Pelecanoididae

Pelicaniformes

Pelicanidae

Phaethontidae

Phalacrocoracidae

Anhingidae

Sulidae

Fregatidae

Ciconiiformes

Ardeidae

Ardeinae

Ardeini

Nycticoracini

Tigriomithini

Botaurinae

Scopidae

Balaenicipitidae

Ciconiidae

Treskiornithidae

Phoenicopteridae

Anseriformes

Anhimidae

Anatidae

Anseranatini

Dendrocygnini

Anserini

Stictonettini

Tadornini

Tachyerini

Anatini

Aythyini

Cairinini

Mergini

Oxyurini

Falconiformes

Cathartidae

Pandionidae

Falconidae

Sagittariidae

Accipitridae

Accipitrinae

Circaetinae

Circinae

Milvinae

Perninae

Polyboroidinae

Elaninae

Machaerhamphinae

Aegypinae

Pteroclidiformes

Pteroclididae

Columbiformes

Columbidae

Psittaciformes

Psittacidae