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

这是一项多国家、多学科的研究项目，旨在调查青藏高原北部的新生代化石。由于难以进入和极端环境，这片辽阔的高原很少被勘探，仍然是古生物勘探的最后前沿。在青藏高原最大的陆相盆地柴达木盆地的初步调查中，发现了一些化石丰富的地点，这些地点跨越了一长串地层，连续出露的地层厚度往往超过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、构造地质学家、沉积地质学家、同位素地球化学家和古地磁学家组成的团队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龄。对河流、湖泊和岸上沉积的沉积学研究也为周围山脉的沉积物来源、古流域的性质和盆地历史的演化提供了进一步的证据。对保存在哺乳动物化石牙齿中的碳和氧同位素的分析提供了关于动物饮食(无论它们是食叶动物还是草食动物)、环境(无论它们生活在森林、草原还是树木茂盛的草原)以及地区气候的有价值的信息。通过综合古生物、磁学、沉积和地球化学等资料，我们希望能够更好地理解青藏高原隆升与晚新生代环境和生物变化之间的联系。将印度和巴基斯坦西藏南坡的动物群与北部的柴达木动物群进行比较，将提供哺乳动物迁徙的线索，以及随着西藏高地继续上升的地理障碍。在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的影响的辩论中，这些新数据尤其相关。

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.