Abstract: Theδ13C values of fossil tooth enamel of middle Miocene Platybelodon danovi cheni, Amebelodon tobieni and Stephanocemas thomsoni from Tongxin, Ningxia ranged from - 8. 7 ‰to - 10. 3 ‰, suggesting that these herbivorous mammals were feeding predominantly on C3 plants. The low-crowned dentitions of these animals indicated that they were browsers. And this supported the diets suggested by stable carbon isotopic compositions of tooth enamel.

摘要： 宁夏同心中中新世Platybelodon danovi cheni, Amebelodon tobieni 和Stephanocemas thomsoni化石牙齿的δ13C 值为- 8. 7 ‰～ - 10. 3 ‰,说明这些动物可能以δ13C值为- 20. 7 ‰～ - 25. 3 ‰的C3植物作为主要食物来源。根据齿冠高低与取食嫩叶或硬草的关系,这三种动物的低冠齿所指示的食性支持了牙齿釉质的碳稳定同位素所指示的食性。