; class Aves, order Galliformes)
A monospecific family (Opisthocomus hoatzin) which is a dark brown, rufous, and buff bird with a stout, short bill, a small head with long crest feathers, a long neck, and a long tail. It is a weak flier, normally clambering through trees. Its young possess claws on their wings and climb well. The hoatzin is arboreal, inhabiting forests, feeds on fruit and leaves, and nests in trees. It is confined to northern S. America.
Subjects: Zoology and Animal Sciences.