Comparing ritual foods and everyday diet from the Middle Horizon site of Tenahaha, Cotahuasi, Peru using stable isotope and macrobotanical analyses

Prehistoric populations actively chose what foods were used in different social and political contexts. Ritual meals may have included special foods or different preparation in contrast with quotidian meals. In this study, we compare plant remains with isotope values from human remains to understand food practices at the site of Tenahaha in the Cotahuasi Valley of highland Peru (CE 850–1050). Built in a time of rapid social change, Tenahaha was a local mortuary center where people stayed for a few days to bury their dead and celebrate ancestors. Most food and drink appear to have been prepared and consumed communally, in contrast to the more private dining practices typical in villages of the era. C₃ foods such as quinoa, tubers, and molle were ubiquitous at the site, suggesting a diet heavy in C₃ foods. In comparison, stable isotope analysis of individuals buried at Tenahaha shows a diet dominated by C₄ plants (maize) and animal products that may have been foddered on maize. A more maize-centric diet was common by the Middle Horizon in the central Andean sierra, replacing diets dominated by C₃ foods. Although taphonomic and sampling concerns must be taken into account, the emphasis on C₃ foods seen macrobotanically at Tenahaha may reflect a desire to consume more traditional foods while honoring the dead.