关键词: 牙齿微磨耗, 食物结构, 生业模式

Abstract:

During chewing, teeth rub against phytoliths in food and foreign gravel in the soil, generating diverse dental microwear patterns on the buccal surface of the teeth. The distinct diet structures of populations with different life patterns lead to varying food particles in their diets, which in turn result in different dental microwear. To explore whether differences in the diet structures of populations with different life patterns would manifest as microwear patterns, the author selected the mandibular first molars of 79 individuals from the Wanggou site in Zhengzhou and the Jinmaoyuan site in Datong. The microwear patterns on the buccal side of the teeth were observed using a Leica DVM6M ultra-depth microscope. The results indicated significant differences in microwear patterns between the two groups. For the Wanggou people, whose main economic activity was agriculture, the average number of striations was 36.95, the average length of striations was 236.89 microns, and the average ratio of horizontal to vertical striations (L_h/L_v) was 120.89%. In contrast, for the Jinmaoyuan people under a mixed economy of agriculture and animal husbandry, the average number of striations was 28.26, the average length of striations was 262.55 microns, and the average L_h/L_v ratio was 83.51%. Compared with the Jinmaoyuan people, the Wanggou people exhibited shorter striations, higher density, and a higher L_h/L_v ratio. The average number of striations in the Wanggou people tended to increase with age. There was little disparity in the striation pattern between men and women of the Wanggou people. However, the mean number and average length of striations in the male youth group were smaller than those in the female youth group, suggesting that young men consumed a relatively higher proportion of meat. For the Jinmaoyuan people, the average number of striations and the length of striations gradually decreased with age, indicating that there were fewer hard particles in the diet of the middle-aged group and the physical properties of the food were softer. The L_h/L_v ratio in the prime-age group was notably lower than in other groups, implying that they might consume more meat. The study on the differences in buccal microwear between the two groups revealed no significant difference in the internal microwear patterns between the two populations, indicating a relatively stable diet structure. Nevertheless, the two groups had substantial differences in buccal microwear patterns, demonstrating that different diet structures would induce different micro-attrition patterns. The high proportion of plant food in the diet structure of the Wanggou site inhabitants led to the high density of striations. The diversified subsistence modes and the cold, dry, and sand-prone climatic environment of the Jinmaoyuan site might incorporate more hard exogenous particles in the residents’ food, resulting in longer striations.

Key words: dental microwear, dietary structure, subsistence mode