Processing it all: Starch residues on Jomon Period ground stone from southern Hokkaido, Japan

Abstract

For the Jomon Period, ground stone technology related to processing activities, such as handstones and querns, are commonly associated with plant foods. In many cases, these tools are considered to be an indicator for the consumption of tree nuts. In this study, ground stone artifacts from 15 sites across southern Hokkaido were analyzed for starchy residues to examine the relationship between grinding tools and economic plant taxa in Jomon daily practices. Overall, 24 of the 76 artifacts examined here had observable starch grains, meaning a large percentage of tools did not appear to have been in contact with starchy plants. The starch types commonly found in underground storage organs (USOs) were the most prominent component of the observed grains, indicating the use of yams, lilies, and other roots or tubers. The evidence for Poaceae grasses, legumes, and nuts is less clear, but present alongside the USO starch granules. These results suggest that grinding implements were not limited to processing plant foods, and would not have been restricted to specific resources, such as nuts.