is a biological order of the phylum Chordata (Chordates) and class Aves (Birds).
Opisthocomidae
Charadriiformes
Casuariiformes
Suliformes
Gruiformes
Leptosomiformes
Cuculiformes
Anseriformes
Falconiformes
Phoenicopteriformes
Galliformes
Podicipediformes
Accipitriformes
Bucerotiformes
Pelecaniformes
Apterygiformes
Gaviiformes
Coraciiformes
Coliiformes
Struthioniformes
Strigiformes
Psittaciformes
Sphenisciformes
Passeriformes
Columbiformes
Rheiformes
Ciconiiformes
Tinamiformes
Trogoniformes
Phaethontiformes
Procellariiformes
Piciformes