text: Typical curassow | All Birds Wiki | FANDOM powered by Wikia
  Typical curassow
  Crax is a genus of curassows from tropical South America. Only the Great Curassow ranges north through Central America as far as Mexico.
  The northern lineage quite soon thereafter radiated into the ancestors of the Great, Blue-billed, and Yellow-knobbed Curassows, which were isolated from each other by the uplift of the northern Cordillera Occidental, and the Serrania del Perija, respectively; it is fairly certain that these lineages were well distinct by the end of the Miocene. (Pereira & Baker 2004)
  The evolution of the 4 southern species was somewhat more complex. In the Messinian, about 6-5.5 mya, the ancestors of the Wattled Curassow became isolated in the western Amazonas basin. With increasing aridification of southeastern Brazil, the ancestors of the Red-billed Curassow found refuge in the mountain ranges between the Brazilian Highlands and the Atlantic during the mid-Zanclean, some 4.5-4 mya. The divergence between the Bare-faced and Black Curassow lineages apparently took place around the Uquian-Ensenadan boundary, some 1.5 mya. This which coincides with one or several period(s) of elevated sea levels during which the lower Amazonas basin was a brackish lagoon which offered little curassow habitat. Their present ranges are consequently still separated by the Amazonas river. (Pereira & Baker 2004)