been thought to be in the Tehuacán valley in connection with one of the earliest neolithic cultures of Mesoamerica, and although it is now in doubt whether Tehuacán was the original home of the Proto-Otomanguean people, it is agreed that the Tehuacán culture (5000 BCE–2300 BCE) were likely Oto-Mangue speakers. The long history of the Oto-Manguean family has resulted in considerable linguistic diversity between the branches of the family. Terrence Kaufman compares the diversity between the main branches of Oto-Manguean with that between the main branches of Indo-European. Kaufman also proposes that Oto-Manguean languages are an important candidate for being the source of many of the traits that have diffused into the other languages in the Mesoamerican linguistic area. Oto-Mangue speakers have been among the earliest to form highly complex cultures of Mesoamerica: the archeological site of Monte Albán with remains dated as early as 1000 BCE is believed to have been in continuous use by Zapotecs. The undeciphered Zapotec script is one of the earliest forms of Mesoamerican writing. Other Mesoamerican cultural centers which may have been wholly or partly Oto-Manguean include the late classical sites of Xochicalco, which may have been built by Matlatzincas, and Cholula, which may have been inhabited by Manguean peoples. And some propose an Oto-Pamean presence in Teotihuacán. The Zapotecs are among the candidates to have invented the first writing system of Mesoamerica – and in the Post-Classic period the Mixtecs were prolific artesans and codex painters. During the postclassic the Oto-Manguean cultures of Central Mexico became marginalized by the intruding Nahuas and some, like the Chiapanec–Mangue speakers went south into Guerrero, Chiapas and Central America, while others such as the Otomi saw themselves relocated from their ancient homes in the Valley of Mexico to the less fertile highlands on the rim of the valleys. Geography and demographics Western branch Oto-Pamean The languages of the Oto-Pamean branch are spoken in central and western Mexico. The group includes the Otomian languages: Otomi spoken primarily in the states of Mexico, Hidalgo, Puebla and Veracruz (c. 293,000 speakers) and Mazahua spoken in the western part of the State of Mexico (c. 350,000 speakers), and the endangered Matlatzincan languages including Matlatzinca (c. 1000 speakers in the town of San Francisco Oxtotilpa) and Tlahuica (also called Ocuilteco) (c. 400 speakers in the municipio of Ocuilan) both spoken in the State of Mexico; And the Pamean group composed of the