张坪洞穴群中田鼠类臼齿形态研究  

Teeth-shape analysis and the species sequence of Microtinae from Zhangping Caves and the nearby ones

作　　者：李永项[1] 薛祥煦[1] 

机构地区：[1]西北大学大陆动力学国家重点实验室/地质学系,陕西西安710069

出　　处：《西北大学学报（自然科学版）》2008年第2期273-276,共4页Journal of Northwest University（Natural Science Edition）

基　　金：陕西省教育厅科研基金资助项目(JK01)

摘　　要：目的探讨田鼠类臼齿的形态变化和种类演替。方法运用经典的古生物学方法,包括化石标本的形态学分析和测量统计等。结果田鼠齿列中M3和m1的长宽比值是其中最大的,其第5齿峡Is5相应的由宽变窄,趋于封闭,第6齿峡Is6从无到有,逐步变小。结论在田鼠臼齿中,M3和m1由于特殊的形态及位置使它们容易延伸变化而成为形态学分析的重点,其形态具有由简单到复杂的变化趋势,研究区及其附近,田鼠类更新世以来的演替顺序分析为Allophaiomys(Q1)—Predromys(Q1)—Microtus(Q2)。Aim To discuss the teeth-shape variations and the species sequence in Microtinae. Methods Using the classical palaeotology methods including measuring, statistics and comparing with other locality fossils. Results The L/W ratios of M3 and ml are of most width in teeth-line of the Microtinae. The Is5 tend close from wide to narrow and the Is6 appear and reduce. Conclusion Most recent work has focused on morphological changes in the molars, especially in M3 and ml, and the rezones may be caused by their special shape and position in teeth-line. The teeth of Microtinae tend from simple to complex as the time passed. In the research area and nearby ones, the species sequence of Microtinae since Mid-Pleistocene may be AUophaiomys（ Q1 ） -Predromys（ Q1 ） -Microtus（ Q2 ）.

关 键 词：田鼠 臼齿形态变化 种类演替 张坪洞穴群 更新世以来 

分 类 号：X703.1[环境科学与工程—环境工程]