Three large language families are thought to have had their most recent common homelands within Mesoamerica. The time frames and locations in which the common ancestors of these families, referred to by linguists as proto-languages, were spoken are reconstructed by methods of historical linguistics. The three earliest known families of Mesoamerica are the Mixe–Zoquean languages, the Oto-Manguean languages and the Mayan languages. Proto-Oto-Manguean is thought to have been spoken in the Tehuacán valley between 5000 and 3000 BCE, although it may only have been one center of Oto-manguean culture, another possible Oto-Manguean homeland being Oaxaca. Proto-Mayan was spoken in the Cuchumatanes highlands of Guatemala around 3000 BCE. Proto-Mixe–Zoquean was spoken on the gulf coast and on the Isthmus of Tehuantepec and on the Guatemalan Pacific coast around 2000 BCE, in a much larger area than its current extension. Totonacan languages, Purépecha, Huave and the Tequistlatecan languages can also be assumed to have been present in Mesoamerica at this point although it is unknown.