Amazon river dolphin widespread river dolphins. They are present in six countries in South America: Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela, in an area covering about . The boundaries are set by waterfalls, such as the Xingu and Tapajós rivers in Brazil, as well as very shallow water. A series of rapids and waterfalls in the Madeira River have isolated one population, recognized as the subspecies "I. g. boliviensis", in the southern part of the Amazon basin in Bolivia. They are also distributed in the basin of the Orinoco River, except the Caroni River and the upper Caura River in Venezuela. 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