萨拉乌苏动物群有关属种的修订与讨论

REVISIONS OF SOME TAXA OF THE SALAWUSU FAUNA FROM SJARA-OSSO-GOL AREA,NEI MONGOL,CHINA

随着地层学和年代学工作的深入开展,对萨拉乌苏河地区的地层划分愈加仔细;原含萨拉乌苏动物群的地层现在被划分为下部的萨拉乌苏组和上部的城川组。相应地,过去的萨拉乌苏动物群也被划分为萨拉乌苏动物群和城川动物群;而萨拉乌苏动物群又被进一步划分为下部组合和上部组合,下部组合含王氏水牛和诺氏古菱齿象化石,与欧洲的末次间冰期对应;上部组合以野驴和披毛犀为主,与末次冰期第一阶段对应。但对萨拉乌苏河地区晚更新世动物群中有些属种的分类命名问题,一直未达成共识,有些甚至存在错误认识。关于萨拉乌苏动物群是否含有肿骨大角鹿的问题,争论持续了近20年。最新研究表明,在萨拉乌苏组中发现的两件有肿厚现象的大角鹿下颌骨,应当归入河套中国大角鹿(Sinomegaceros ordosianus),而非肿骨大角鹿。因为,下颌骨肿厚是大角鹿类所有种的共有特征。过去很多文献中提到萨拉乌苏动物群中有"蒙古鹿",经笔者核对,该名称最早被用于"大角鹿蒙古变种"(Cervus megacerosvar.mongoliae)和"蒙古马鹿"(Cervus mongoliae);但这两个名称后来均被弃置不用。关于萨拉乌苏动物群中的恰克图转角羚羊,后来曾有人将其转入许家窑扭角羚,经笔者研究,认为萨拉乌苏河地区的转角羚羊应保持原有名称,即恰克图转角羚羊。

All the mammalian fossils from the Late Pleistocene beds of Sjara-Osso-Gol area had been regarded as a unique fauna for quite a long time. Along with the progress in stratigraphy and chronology,the fauna has been divided into small units. Currently the Salawusu Fauna is divided into two assemblages; the lower one contains Bubalus and Palaeoloxodon, which represent warm climate of the Riss-Würm interglacial, while the upper one is mainly composed of Coelodonta and Equus,which coincides with the Würm Ⅰ-Ⅱ and their interstadial. Whether or not Sinomegaceros pachyosteus existed in the fauna has been debated for two decades. The recent study shows that the two mandibles with thickened mandibular body should be asigned to Sinomegaceros ordosianus instead of Sinomegaceros pachyosteus because the thickening of mandibular body is a unique character for all species of the Tribe Megacerini. In some previous publications, the faunal list of the Salawusu Fauna contains the species name Cervus mongoliae. It is an invalid name as 1 ）the material was from other locality rather than Sjara-Osso-Gol and 2）the name was regarded as a junior synonym of Cervus elaphus. The name of Spirocerus kiakhtensis in the Salawusu Fauna was replaced with Spirocerus hsuchiayaocus by some authors in the past decades. Through the study by the present authors, it seems that the species Spirocerus hsuchiayaocus,which was based on one poorly preserved horn core only, is not quite reliable. The antelope with spiral horns in Salawusu Fauna should be maintained within the species Spirocerus kiakhtensis. Currently the Salawusu Fauna contains 33 mammalian species,including undeterminable species and taxa.