记陕西洛南张坪洞穴群中更新世绒[鼠平](Caryomys)

ON TWO SPECIES OF CARYOMYS(CRICETIDAE,RODENTIA)FROM MIDDLE PLEISTOCENE ZHANGPING CAVES,LUONAN COUNTY,SHAANXI PROVINCE

详细描述了陕西洛南张坪洞穴群中中更新世的洮州绒(鼠平)(Caryomys eva)和苛岚绒(鼠平) (C.inez),讨论了绒(鼠平)属的分类地位。分析显示,C.eva各齿测量的平均值小于C.inez;两种臼齿形态从约493 kaBP以来无显著变化,显示出该属的原始性质。

The Middle Pleistocene Caryomys from Zhangping caves, Luonan County, Shaanxi Province is described into two extant species, C. eva and C. inez, that only live in North China. C. eva is characterized by 5 lingual and 4 buccal salient angles on ml and by 3 lingual and 3 buccal salient angles on M3. C. inez is slightly more complicated than C. eva because its ml has 6 lingual salient angles and its M3 has an elongated posterior loop with the fourth lingual salientangle sometimes. It is different from C. regulus living in Korea which has only 5 lingual salient angles on ml and has the fourth lingual and buccal salient angles on M3. The average values of teeth are distinctly larger in C. inez than in C. eva （see Tables 1 and 2）. The fact that the teeth have not evolved since middle Middle Pleistocene （493 ± 55 ka BP） indicates that the genus Caryomys is a relatively conservative member of the subfamily Arvicolinae. Thomas （1911 ） proposed Caryomys as a subgenus of Microtus to contain the Chinese species inez, eva, nux and alcinous. Hinton （1925） at first elevated Caryomys to genus but later （1926） put it in Evotomys （ = Clethrionomys） because he considered the holotypes of these species to be juvenile specimens of E. rufocanus shanseius. Allen （1940） concurred in recognizing inez （include nux） and eva （include alcinous） as two independent species but in the subgenus of Eothenomys. The specific validity of both is currently accepted （ Nowak and Paradiso, 1983; Wang, 1991; Corbet and Hill, 1991; Wang and Xu, 1992; Huang et al., 1995）. Ma and Jiang （1996） maintained to rehabilitate the Caryomys as genus based on the karyotypic study. Both eva and inez have 2n = 54 with mostly subtelocentric pairs, while all Clethrionomys and Eothenomys sampled have 2n = 56 with one metacentric pair. This result has been accepted by some biologists （Luo et al., 2000; Ye et al., 2002; Wang, 2003; Wilson and Reeder, 2005 ）. The present authors also follow this view point.