Kayapo people - A Brazilian Indigenous group from the plain lands of the Mato Grosso and Pará in Brazil, south of the Amazon Basin and along Rio Xingu and its tributaries. Kayapo is an exonym, as the autonym is Mebêngôkre, "the men from the water hole." Older men insert disks in their lower lips. Kayapo language, belongs to the Jê language family. A type of sweet potato is sometimes named "caiapo", after the tribe. As many other tribes, they are under the threat of environmental issues, and their claim was marked by an important demonstration they made during the Altamira Gathering five-day media conference (February 19 to 24, 1989) organized by the Coordination of the Indigenous Organizations of the Brazilian Amazon.