Mapping the chronology of an ancient cosmovision: 4000 years of continuity in Pecos River style mural painting and symbolism.

Forager societies in southwest Texas and northern Mexico painted polychromatic Pecos River style murals in limestone rock shelters containing well-preserved archaeological assemblages. To establish the temporal context of the murals, we obtained 57 direct radiocarbon dates and 25 indirect oxalate dates for pictographs across 12 sites using plasma oxidation and accelerator mass spectrometry. Bayesian modeling estimates that Pecos River style began between 5760 and 5385 calibrated years before the present (cal B.P.) and probably ended in 1370 to 1035 cal B.P. Painting spanned a duration of 4095 to 4780 years (68.3%). Stratigraphic and iconographic analyses revealed that eight of the murals were created as compositions adhering to a set of rules and an established iconographic vocabulary. Results suggest consistent messaging throughout a period marked by changes in material culture, land use, and climate. We propose that Pecos River style paintings, embedded in a cultural keystone landscape, faithfully transmitted a sophisticated metaphysics that later informed the beliefs and symbolic expression of Mesoamerican agriculturalists.