Timbira was the name given to the non-Tupi speaking groups of the Parnaíba river in the 18th century. These were the probable ancestors of the many groups that spread, from the 19th century on, to a large area in the west, as far as the Tocantins river. They are the Pukobye, Parkateye, Krikati, Kraho and others whose frequent -ye suffix in their ethnonyms served to give name to the language family. An earlier migration is that of the Apinayé, whose language is much closer to that of the Kayapó and Suyá - the only groups to cross the Araguaia to the west, in the early 18th century. The Kayapó, self named Mebengokre ("people from the place between the rivers" - a probable reference to their original homeland in the confluence of the Araguaia and the Tocantins) are a large group occupying a huge territory to the west, reaching the upper Xingu river. All of these groups build ring villages, with matrilocal houses around the plaza, though there is not necessarily a men's house. Swidden farming in sedentary villages combined to periods of high mobility in hunting expeditions is the basis of the economy of all northern Jê groups. Unlike the Xavante and Kaingang, here the existence of moieties is limited to a ritual function, and does not regulate marriage. The kinship terminology is also of a different kind, closer to Crow-Omaha types, with no positive rule of marriage. As for the Panará of the upper Xingu, they are the last descendents of a once numerous group, the Southern Kayapó, whose territory extended from western São Paulo to Mato Grosso. Persecuted by the European expeditions of conquest, they fled constantly towards west until they reached their last refuge in what is today the Xingu National Park.