秦皇岛山羊寨洞穴堆积中的中更新世麝鼩Crocidura类化石

THE Crocidura FOSSILS(INSECTIVORA,MAMMALIA) FROM CAVE DEPOSITS IN THE MIDDLE PLEISTOCENE OF SHANYANGZHAI SITE,HEBEI PROVINCE,CHINA

河北秦皇岛山羊寨洞穴堆积中发现的中更新世麝鼩Crocidura类化石,包括翁氏麝鼩c.wongi和3个麝鼩未定种。翁氏麝鼩C.wongi的P4前附尖小、刃状纵脊发育、平均尺寸介于大麝鼩C.lasiura和小麝鼩C.suaveolens之间,与周口店、金牛山等的特征基本一致。C.sp.1的P4冠面形态类似于Sorex型,前附尖相对发育,并与前尖相连,使唇侧纵脊由相对较矮的前附尖、高大的前尖及其后尖三尖相连而成;C.sp.2的M2长方形,长比宽小四分之一,与其他种近方形的臼齿明显不同,其MS较少退化;C.sp.3齿冠形态基本上为Sorex型,由两个三角形的齿座组成w形,下中尖发育,下斜脊唇侧视为不对称的V形或倾斜的L形,但它的齿尖却不染色。这些形态差异可能暗示了这一时期中国北方的此类化石可能并非翁氏麝鼩C.wongi这一种。

White-toothed shrew （ C （40°05′13″N, 119°31 ′50″E） rocidura） fossils were found in the Middle Pleistocene Shanyangzhai cave sediments in Qinghuangdao, Hebei Province of China. They include C. wongi and three C. sp. of C. wongi has a small parastyle and a long blade-like tritocone,with a mean size falling in the range between C. lasiura and C. suaveolens. It is much closer to the specimens from the Zhoukoudian and Jinniushan. P4 tooth morphological characters of the C. sp. 1 are similar to those of Sorex. Its labial ectoloph is linked with a short parastyle and a long paracone and a long metacone. M2 of C. sp. 2 looks like a rectangular,which is different from the quadrate molar of the other species. M3 of C. sp. 2 has less degeneration. The crowns of the ml and m2 of C. sp. 3 looks like these of Sorex, with W-shaped trigonid and talonid. Its mesoconid is very developed and the crista obliqua looks like an asymmetry V shape or a tilted-L shape,but it does not show pigment on the tip. These variations may suggest that there are more than one species of C. wongi during the Middle Pleistocene in North China. Up to now,there have been six fossil species reported at 15 sites in China. Only two species are from two locations of Neogene, and the other four species are from the 13 locations of Quaternary（not including three sites of Crocidura sp. ）.