Iriri River Iriri River The Iriri River () is a large tributary of the Xingu River in Brazil, in the state of Pará. It is long making it the 116th longest river in the world (with Krishna River, India) and the 15th longest in the Amazon basin. The headwaters are the traditional home of the Panará people. The river rises in the Nascentes da Serra do Cachimbo Biological Reserve, a strictly protected conservation unit established in 2005 in the Serra do Cachimbo. It is one of the headwaters of the Xingu River. It flows for before joining the Xingu, running through the
Xingu-Tocantins-Araguaia moist forests 8 species of primates including the white-nosed saki ("Chiropotes albinasus"), red-handed tamarin ("Saguinus midas"), red-bellied titi ("Callicebus moloch"), Azara's night monkey ("Aotus azarae infulatus") and white-cheeked spider monkey ("Ateles marginatus"). The last two are endemic to this ecoregion and the Tapajós-Xingu moist forests to the west. Other species of mammals include white-lipped peccary ("Tayassu pecari"), collared peccary ("Pecari tajacu"), cougar ("Puma concolor"), jaguar ("Panthera onca"), South American tapir ("Tapirus terrestris"), brocket deer (genus "Mazama"), bare-tailed woolly opossum ("Caluromys philander"), and seven-banded armadillo ("Dasypus septemcinctus"). Endangered mammals include white-cheeked spider monkey ("Ateles marginatus"), black bearded saki ("Chiropotes satanas") and giant otter