Collaborative Research: Vertebrate Paleontology and Paleoenvironments of the Richest, Endemic-Dominated Vertebrate Assemblage in Cenozoic of Qaidam Basin, Tibetan Plateau, China

摘要青藏高原北部新生代化石调查是一项多国、多学科的研究项目。由于难以进入和极端的环境，广阔的高原很少被探索，仍然是古生物学探索的最后前沿。在青藏高原最大的陆相盆地柴达木盆地的初步调查中，已经发现了许多富含化石的地方，这些地方跨越了一长串的地层，通常在连续暴露时厚度超过5000米。从中新世早期（大约2400万到1600万年前）到上新世（大约500万到200万年前），这样一个非常完整的记录揭示了许多以前科学未知的东西。一个由古生物学家、构造和沉积地质学家、同位素地球化学家和古地磁学家组成的研究小组正在系统地收集柴达木盆地的哺乳动物、鱼类和植物化石，并研究它们的古环境。结合古地磁研究，这些化石有助于确定保存它们的岩石的年代。对河流、湖泊和河岸沉积物的沉积学研究也为周围山脉沉积物的来源、古排水的性质和盆地历史的演变提供了进一步的证据。对哺乳动物牙齿化石中保存的碳和氧同位素的分析提供了有关动物饮食（它们是吃树叶还是食草动物）、环境（它们是生活在森林、草原还是树木繁茂的草原上）和区域气候的宝贵信息。通过整合古生物、地磁、沉积和地球化学等资料，我们希望更好地了解青藏高原隆升与晚新生代环境和生物变化之间的联系。将西藏南坡位于印度和巴基斯坦的动物群与北部的柴达木动物群进行比较，将为青藏高原持续上升过程中哺乳动物的迁徙和地理障碍提供线索。这些新数据与当前关于青藏高原上升对欧亚大陆新生代气候、植被和哺乳动物进化影响的争论尤其相关。

ABSTRACTThis is a multi-national, multidisciplinary research project to survey Cenozoic fossils in the northern Tibetan Plateau. Due to difficulties of access and extreme environments, the vast plateau is little explored and remains the last frontier for paleontological explorations. Preliminary surveys in the Qaidam basin, the largest terrestrial basin in the Tibetan Plateau, have yielded a number of richly fossiliferous localities spanning a long sequence of strata often more than 5,000 meters thick in continuous exposures. Ranging from early Miocene (about 24 to 16 million years ago) to Pliocene (about 5 to 2 million years ago), such a remarkably complete record reveals much that was previously unknown to science. A team of paleontologists, structural and sedimentary geologists, isotope geochemists, and paleomagnetists is systematically collecting fossil mammals, fishes, and plants in the Qaidam basin and studying their paleoenvironments. Combined with paleomagnetic studies, the fossils help to establish the ages of the rocks in which they are preserved. Sedimentologic studies on the river, lake, and over-bank deposits also provide further evidence for the sources of the sediments from the surrounding mountains, the nature of the paleodrainages, and the evolution of the basin history. Analyses of carbon and oxygen isotopes preserved in fossil mammalian teeth provide valuable information about animals' diets (whether they were leave browsers or grass grazers), environment (whether they lived in a forest or on a grassland or in a wooded grassland), and regional climate. By integrating the paleontologic, magnetic, sedimentary, and geochemical data, we hope to achieve a better understanding of the links between the uplift of the Tibetan Plateau and the late Cenozoic environmental and biotic changes. Comparisons of faunas from the southern slope of Tibet in India and Pakistan with the Qaidam faunas to the north will offer clues of mammalian migrations and geographic barriers as the high Tibet continued to rise. The new data are particularly relevant in the current debate over the impact of the rising Tibetan Plateau on climate, vegetation, and mammalian evolution in the Cenozoic of Eurasia.