Starch grains from human teeth reveal the plant consumption of proto-Shang people (c. 2000–1600 BC) from Nancheng site, Hebei, China

The founding processes of the first state of ancient China with a known written record, the Shang dynasty (3600–3046 cal BP), have been poorly understood. Recent discoveries of a host of archaeological sites dating to the proto-Shang culture (4000–3600 cal BP) have helped elucidate the transition to the Shang culture. Nevertheless, there are few investigations about the mode of subsistence and economy of the proto-Shang culture, and how this might have shaped the transition to statehood. In this present study, we analyzed the starch grains preserved in dental calculus and teeth surfaces from 16 samples from the site of Nancheng in order to gain a better understanding of the subsistence strategy and plant consumption of proto-Shang people. We also performed experiments to test how different cooking methods may lead to size changes in the starches of four Poaceae plants, in order to identify the processing methods used by the proto-Shang people. The results indicate that Triticum aestivum , Coix lacryma-jobi , Setaria italica and some yet-unidentified roots and tubers were consumed by these individuals. These data indicate a broader spectrum of plant consumption than that seen by previous archaeobotanical and stable isotope analyses. Such a broad spectrum of plant consumption provided a substantial economic base for proto-Shang people and might be one of the factors supporting the subsequent development of the Shang state culture.