Collaborative Research: Late Cenozoic Vertebrate Paleontology and Paleoenvironments of the Tibetan Plateau (China)

这是一个多学科的国际合作项目，研究青藏高原新生代脊椎动物化石和古环境。青藏高原的隆升和生长与过去2000万年来的区域和全球气候和环境变化有关。逐渐变冷和变干的条件，可能与东亚冬季风的发展有关，似乎是一个长期的趋势，并在生物群落上留下了深刻的印记。我们在西藏札达、昆仑山口和柴达木盆地的初步勘探，由美国国家科学基金会资助，已经收集了大量脊椎动物化石，包括哺乳动物、鱼类和海龟。柴达木盆地上新世鱼类对西藏干旱化高度敏感，札达盆地哺乳动物化石表明冰期巨型动物成分起源于高原。总的来说，这些化石组合暗示了在中新世晚期到上新世（1200 - 260万年前）的某个时候出现了一种特有的动物群。这笔新的赠款将使我们能够大大扩展我们的研究计划，努力详细了解高原增长造成的动物地理障碍和环境波动，以及这些深刻的变化如何影响该地区的哺乳动物。一个由古生物学家、构造和沉积地质学家、稳定同位素地球化学家和古地磁学家组成的国际团队将在西藏进行野外工作，试图实现以下几个目标：（1）系统收集这些盆地中的哺乳动物和鱼类化石;（2）建立基于生物地层学和磁性地层学的区域年代框架;（3）恢复沉积环境和盆地历史及其与周围山脉隆升和生物事件的关系：（4）根据化石鱼类的亲缘关系研究高原水系;（5）分析稳定同位素，以探讨哺乳动物食草动物的饮食、植物群落以及区域气候和水文循环的变化;（6）从动物群演替、沉积作用和稳定同位素等方面探讨西藏崛起的环境意义。我们的古生物学探索的结果可能是变革性的，因为对青藏高原的探索不足产生了独特的化石，这些化石对环境变化和适应、动物地理障碍和冰河时代巨型动物的起源具有指导意义。化石脊椎动物填补了目前关于该地区过去生物世界和古环境的争论中的一个关键缺失部分，因为高原上升到一个临界高度，形成了动物迁移的强大障碍，形成了新的排水系统，并从根本上影响了新生代晚期北方半球的气候。这些新的数据有望对几种假说进行检验，这些假说涉及几种局限于高原的独特哺乳动物的系统关系、高原生长的时间和速度、构造剧变的环境影响以及哺乳动物、鱼类和植物的地理学后果

This is a multidisciplinary, international collaborative project to study Cenozoic vertebrate fossils and paleoenvironments of the Tibetan Plateau. The uplift and growth of the Tibetan Plateau have been linked to regional and global climatic and environmental changes during the past 20 million years. Progressively cooler and drier conditions, possibly linked to the development of East Asian winter monsoon, seem to be a long-term trend and left deep marks on biological communities. Our preliminary explorations in Zanda, Kunlun Pass, and Qaidam basins in Tibet, funded by a prior NSF grant, have resulted in a tantalizing collection of fossil vertebrates including mammals, fishes, and turtles. Pliocene fishes from the Qaidam Basin are highly sensitive to the drying of Tibet and fossil mammals from the Zanda Basin suggest the origin of Ice Age megafauna elements from high plateau. Collectively these fossil assemblages hint at the emergence of an endemic fauna sometime in the late Miocene to Pliocene (12-2.6 million years ago). This new grant will allow us to greatly expand our research program that strives to gain a detailed understanding of zoogeographic barriers and environmental volatility resulting from the growth of the high plateau and how these profound changes have affected mammals in that region. An international team of paleontologists, structural and sedimentary geologists, stable isotope geochemists, and paleomagnetists, all experienced in fieldwork in Tibet, will attempt to achieve several objectives: (1) systematic collections of fossil mammals and fishes in these basins; (2) establishment of a regional chronologic framework based on the integration of biostratigraphy and magnetostratigraphy; (3) reconstruction of depositional environments and basin history and their relationships to the uplift of surrounding mountains and biologic events; (4) studies of the plateau drainage systems based on genealogical relationships of fossil fishes; (5) analyses of stable isotopes to explore changes in the diets of mammalian herbivores, plant communities, and regional climate and hydrological cycle; and (6) explorations of environmental implications related to the rising of the Tibet based on information of faunal successions, sedimentation, and stable isotopes. Results of our paleontological exploration are likely transformative because the poorly explored Tibetan Plateau yields unique fossils that are instructive about environmental changes and adaptations, zoogeographic barriers, and Ice Age megafauna origins. Fossil vertebrates fill a crucial missing piece of the puzzle in the current debate on past biological world and paleoenvironments in the region as the Plateau elevated to a critical height to form a formidable barrier for animal migration, to forge new drainage systems, and to fundamentally affect the climate of the northern hemisphere during the late Cenozoic. These new data are expected to afford testing of several hypotheses regarding systematic relationships of several unique mammals restricted to the plateau, timing and rate of growth of the plateau, environmental implications of the tectonic upheaval, and biogeographic consequences for mammals, fish and plants