中国新近纪哺乳动物群的演化与青藏高原隆升的关系

Evolution of the Chinese Neogene Mammalian Faunas and Its Relationship to Uplift of the Tibetan Plateau

新近纪哺乳动物的起源、辐射、扩散、绝灭等方面反映了气候环境的重大变化,晚新生代青藏高原的形成对东亚地区哺乳动物的演化具有直接而深远的影响。高原的隆升使自然环境发生改变,环境的变化又导致动物组成和分布的分异,以及动物对环境适应性的调整。中国新近纪哺乳动物化石研究的结果不仅表明哺乳动物群的组成和特征具有明显的区域性差异,而且中国还是一些代表性门类的起源扩散中心,也是哺乳动物洲际迁徙的关键通道。青藏高原新近纪晚期的哺乳动物群具有非常重要的意义,因为在随之而来的第四纪冰期中这些寒冷适应性动物获得了优势地位,由此成为现代动物地理区系和多样性的基础。通过以点带面的综合研究,将能够全面地认识新近纪动物地理区系对重大气候事件的响应,更准确地判断青藏高原隆升对陆地生态系统的影响。

The origin,radiation,dispersal,and extinction of the Neogene mammals provide important insights in our understanding of mammalian geographical distribution and regional differentiations,and such an evolutionary history can,in turn,reflect significant changes in climate and environments. Mammals are very sensitive to climatic and environmental changes,and their distribution is closely related to their natural habitats. Throughout the late Cenozoic,the formation of the Tibetan Plateau also had a profound influence on the evolution of mammals in East Asia. The uplifting plateau was a major drive in changes of natural environments,which have a direct impact on the differentiation of the faunal composition and distribution. The Chinese Neogene mammalian fossil records are unparalleled in the world,and with its unique zoogeographical position,such a record of faunal compositions is sensitive to regional differentiations. Furthermore,China was a center of origin and dispersal for many representative mammalian groups,and also a key intersection for intercontinental migrations. Most taxa of the distinctive modern mammalian fauna of the Tibetan Plateau have long life history in this plateau,which indicate that they have long-term adaptation procedures within the high-elevation plateau. The late Neogene mammalian fossils from the Tibetan Plateau suggest that some Quaternary mammals first evolved in Tibet before the beginning of the Ice Age. The cold winters in high Tibet served as a habituation ground for the members of the megafauna,which became pre-adapted for the Ice Age,successfully expanding to the Eurasian mammoth steppe. As a result,the research on the Neogene mammalian faunas of the Tibetan Plateau will be focused,because these cold-adapted mammals were dominant in the subsequent Quaternary Ice Age,and become the basis of the modern mammalian zoogeographical patterns and biodiversities. Taking advantage of the above favorable conditions,the response of the Neogene zoogeographical regionalism to the major climatic events and more accurately judge the influence of the Tibetan Plateau uplift to the terrestrial ecosystem can be more accurately judged.