广西崇左三合巨猿大洞早更新世小哺乳动物群

MICROMAMMALS OF THE GIGANTOPITHECUS FAUNA FROM SANHE CAVE,CHONGZUO,GUANGXI

最近在广西崇左三合大洞发现了步氏巨猿和似人似猿共生的新层位,与之伴生的有52种小哺乳动物,占三合大洞巨猿动物群总数的62%,其中苏门答腊兔（Nesolagus）是东南亚地区首次发现的化石。小哺乳动物群以南方早更新世常见的偏皮氏毛耳飞鼠（Belomys parapearsoni）、中间猪尾鼠（Typhlomys intermedius）、拟低冠竹鼠（Rhizomys brachyrhizomyoides）、硕豪猪（Hystrix magna）、先社鼠（Niviventer preconfucianus）、拟爱氏巨鼠（Leopoldamysedwardioidesi）等为代表,根据小哺乳动物群性质和与其他动物群对比以及磁性地层年代测定,表明其时代应是早更新世中期（约距今120-160万年前）。该动物群由树鼩、扁颅蝠、小彩蝠、飞松鼠、笔尾树鼠、猪尾鼠等几乎是旧大陆热带-亚热带森林型动物组成,缺少北方类型,基本上属于热带森林动物群,这表明了当时的自然景观为温暖湿润的热带雨林环境。三合大洞小哺乳动物群是广西地区的首次发现,对华南早更新世巨猿动物群详细划分,探讨步氏巨猿演化和早期人类环境背景等目前科学界关注的问题具有重要的意义。

Sanhe Cave is located in the Chongzuo Ecological Park, about 16km to the northeast of Chongzuo City, Guangxi （22°16. 493′N,107°30. 663′E）. Recently, a new horizon with the coexistence of Gigantopithecus blacki and cf. Ponginae or cf. Homininae was recovered from the sediments in Sanhe Cave. Besides 32 species of large mammals, 52 species of micromammals,62% of the entire Gigantopithecus fauna from Sanhe Cave at the family level,were also obtained by screen-washing method. Because micromammals co-occurring with Gigantopithecus has rarely been reported and studied before ,the discovery of the micromammal fauna from Sanhe Cave will take a significant role in the subdivision, ecological and environmental study of the Gigantopithecus fauna in South China. Faunal comparisons show that the age of the micromammal fauna from Sanhe Cave is middle Early Pleistocene, because it is later than the early Early Pleistocene Longgu Cave fauna from Jianshi, Hubei, but similar with the age of the Longgupo fauna of Wushan. This is also in agreement with the magonetostratigraphic study result, which indicates the micromammal-bearing sediments correspond to the interval between Gilsa-Cobb Mtn. subchron of Matuyama chron（ about 1.2 - 1.6Ma）. The micromammal assemblage is featured by the appearances of common faunal elements from the Early Pleistocene of South China ,such as Belomys parapearsoni, Typhlomys intermedius ,Rhizomys brachyrhizomyoides,Hystrix magna, Niviventer preconfucianus, Leopoldamys edwardioidesi, and so on. The fauna is nearly completely composed of tropic-subtropical forest elements of the Old World, such as Tupaia belangeri, Tylonycteris fulvidus, Kerivoula hardwickei, Pteromys sp., Chiropodomys gliorides, Typhlomys, and so on, which indicates that it is a typical tropical forest fauna among the Quaternary faunas of South China found until now, and that the natural landscape then was tropical rain forest. The micromammal fauna from Sanhe Cave has higher species richness than present （52 species in the micromammal fauna from Sanhe Cave, while presently only 39 species） ,so it can be concluded that the climate then was warmer than present. Among all the micromammal species, Nesolagus is the first fossil record. The living Nesolagus mainly inhabits Indonesia, and also rarely reported from Vietnam. The appearance of fossil Nesolagus in the micromammal fauna from Sanhe Cave implies the Chinese origin of this genus.