Starch grains on human teeth as evidence for 4000 BCE potato consumption at the Cruz Verde site, northern coast of Peru

Abstract

Cruz Verde, located on the north coast of Peru in the Chicama River Basin, is an artificial mound formed by the continuous disposal of food residues between 4200 and 3800 cal. BC. It is a vital archaeological site for understanding the early maritime community that was established in the coastal areas of Peru during the middle Holocene period. Previous studies focusing on animal remains have shown that a wide range of marine resource uses were flexibly maintained in a changing environment. However, the use of plants by coastal fishermen, which has been reported in recent years at other sites in the same region, was not evident at Cruz Verde. This paper reports on an examination of starch grains preserved in the dental calculus of human teeth excavated from the mound at Cruz Verde, which provides direct evidence of the early consumption of cultivated food plants, such as maize (Zea mays), manioc (Manihot esculenta), squash (Cucurbita sp.), and potatoes (Solanum tuberosum). Not only did the results indicate early use of maize indicated in previous studies, but they also confirmed that the use of potatoes at the site dates back to at least 4000 cal. BC—the oldest example from the coastal region of Peru. The micro-botanical data from Cruz Verde suggest that fishing and plant cultivation were combined in the development process of early settlement. Furthermore, the data on this earliest potato use in the coastal area are significant because they contribute to the empirical foundation of understanding the early relationship with maritime and highland communities during this period.