甘肃秦安安湾的托氏原互棱齿象(Protanancustobieni)化石及其剖面.PDF

Advances in Geosciences 地球科学前沿, 2012, 2, 150-158 /10.12677/ag.2012.23022 Published Online September 2012 (/journal/ag.html) Protanancus tobieni from the Anwan Section, Qin’an County, * Gansu Province 1# 2 1,3 Shiqi Wang , Duoqing Wang , Qinqin Shi 1Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 2Qin’an Museum, Qin’an 3Graduate University of the Chinese Academy of Sciences, Beijing Email: #wangshiqi@ Received: Jun. 11th nd th , 2012; revised: Jul. 2 , 2012; accepted: Jul. 11 , 2012 Abstract: We report a specimen of Protanancus tobieni discovered in 1976 from the Anwan Section, Qin’an County, Gansu Province, including a complete mandible with lower incisors and a complete left upper incisor. The material can be referred to the same species as P. tobieni from the middle Miocene Dingjiaergou locality, Ningxia Hui Autonomous Region, because they show almost identical characters. The mandibular symphysis is extremely elongated; the upper incisor is robust with a broad enamel band; the lower incisor is flattened with a biconcave, concentrated-laminated cross-section; and the m3 shows posttrite ornamentation and pseudo-anancody. The above features indicate that the specimen is referable to Protanancus rather than Amebelodon , as it has be