Хоацин құсы және оның туыстары

Family of birds

Opisthocomidae is a family of birds, the only named family within the order Opisthocomiformes. The only living representative is the hoatzin (Opisthocomus hoazin) which lives in the Amazon and the Orinoco delta in South America. Several fossil species have been identified, including one from Africa and one from Europe. and Mayr & De Pietri 2014. Genus ?†Foro Olson 1992 (mid Eocene, USA) cuculiform? Species †Foro panarium Olson 1992
Genus ?†Onychopteryx Cracraft 1971 (Early Eocene of Argentina) – falconid? A nomen dubium
Species †Onychopteryx simpsoni Cracraft 1971
Genus †Protoazin Mayr & De Pietri 2014 (late Eocene of France)
Species †Protoazin parisiensis Mayr & De Pietri 2014
Genus †Namibiavis Mourer Chauviré 2003 (Middle Miocene of Namibia)
Species †Namibiavis senutae Mourer Chauviré 2003
Genus †Hoazinavis Alvarenga, Mayr & Mourer Chauviré 2011 (Late Oligocene and Early Miocene of Brazil)
Species †Hoazinavis lacustris Alvarenga, Mayr & Mourer Chauviré 2011
Genus †Hoazinoides Miller 1953 (middle Miocene of Colombia)
Species †Hoazinoides magdalenae Miller 1953
Genus Opisthocomus Illiger 1811
Species Opisthocomus hoazin (Müller 1776) Illiger 1811 [Phasianus hoazin Müller 1776]

The only living representative is the hoatzin (Opisthocomus hoazin), which lives in the Amazon and the Orinoco delta in South America. The hoatzin is found in the rainforest of the Amazon. It has a long, permanently erected crest which gives the species a stunning silhouette. This gregarious species is often found in groups of more than 40 birds, and up to 100 birds during breeding season which occurs during rainfalls. This is a process called foregut fermentation. It rarely drinks because its diet includes water. The hoatzin is sedentary and widespread in suitable habitat. They are noisy birds, calling in unison, uttering large numbers of varied sounds. In addition to foregut fermentation, the hoatzin has a highly modified skeleton to accommodate its large crop, and in the young of this species, wing claws at the wrist joint which are used to climb among the branches of the nest tree.