Plant domestication, cultivation, and foraging by the first farmers in early Neolithic Northeast China: Evidence from microbotanical remains

North China is regarded as a center of domestication for broomcorn millet (Panicum miliaceum) and foxtail millet (Setaria italica ssp. italica). The Neolithic Xinglonggou site (ca. 8000-7500 cal. BP) in the Liao River region has revealed the earliest macrobotanical evidence of domesticated millets in Northeast China, but controversy remains as to the importance of the millets in human diet. We employed an interdisciplinary approach involving analyses of starch grains, phytoliths, and usewear patterns to study a range of materials from Xinglonggou, including grinding stones, human dental calculus, and vegetative charcoal. The results demonstrate a broad spectrum of plant exploitation by the first farmers in Northeast China rather than dependence upon singular crops. Furthermore, three types of underground storage organs appear to be major staples, while millets were secondary to another early and important cultivated cereal, Job's tears (Coix lacryma-jobi L.). Wild grasses and acorns also account for small portions of plants used. This study documents the northernmost and earliest occurrence of Job's tears in temperate Northeast China, a species which may have originated in the subtropical regions. We argue that Job's tears may have been one of the earliest domesticates in China along with millets.