内蒙古宁城道虎沟及邻区中-晚侏罗世生物集群死亡事件研究

Numerous exceptionally preserved fossils have been uncovered from the Middle-late Jurassic Yanliao Biota in northeastern China. Comparing with the great achievement in study of systematic paleontology, few taphonomic studies have been carried out. Many questions concerning the preservation of the biota remain open. These include the causes of mass mortalities, the subsequent process of transport and burial of the organism remains, especially those who lived on land, and the environmental factors that influenced the formation of exceptional preservation. .The fossils from mass mortality events and their embedding sediments contain key information about the causes of the events and the process that how the organism remains were transported and buried to lakes. Biostratinomic analysis on the fossils and their embedding beds is critical to answer these aforementioned questions. In the proposed project, the Daohugou and its adjacent areas, Ningcheng, Inner Mongolia are selected as a case study. By means of intensive field investigation, high-resolution excavation and detail statistics of taphonomic attributes, this project addresses to understand the causes of mass mortality events, the subsequent process of transport and burial of the organism remains, and the environmental factors that influenced the formation of exceptional preservation addresses to understand by analyzing the paleoenvironment under which the Yanliao Biota were preserved and the taphofacies of the Yanliao Biota.

中国东北中-晚 侏罗世燕辽生物群产出了大量保存精美的动植物化石。相对于系统古生物学研究取得的巨大进展，燕辽生物群的埋藏学研究还相对较少。有关这一特异埋藏化石群如何形成的一系列基本问题，如什么事件引起生物的大量死亡、生物遗体尤其是陆生动物是如何被搬运和埋葬到湖泊中的、哪些导致了化石的特异埋藏等，都还没有得到充分的研究。.生物集群死亡事件以及生物遗体在湖泊中的搬运和埋葬过程必然会在化石和沉积物中留下证据。对死于生物集群死亡事件的化石及其赋存岩层进行生物层积学研究，无疑是解决燕辽生物群埋藏学研究中存在的问题的关键。本次研究拟以宁城道虎沟及与其邻区为案例，采用详细的野外调查与现场挖掘和统计相结合的方法，通过分析这一地区燕辽生物群保存的沉积环境和埋藏相，探讨引发这一地区中-晚侏罗世生物集群死亡的事件成因、生物遗体的搬运和埋葬过程以及影响化石特异埋藏的主导因素。

通过详细的野外调查和小范围的系统挖掘，项目组对道虎沟及其相邻地区道虎沟层的沉积环境和特异埋藏化石的形成机制进行了研究。研究成果揭示了侏罗纪中晚期频繁的火山喷发在道虎沟地区形成了广泛的火山碎屑冲积裙和一些短期的湖泊。受大量火山碎屑注入的控制，这些湖泊的分布区域频繁波动甚至很快消失。详细的埋藏学分析发现道虎沟层陆生动物分异度高，丰度相对较低，保存完整程度高。同层产出的叶肢介化石个体大小频率曲线显示单峰、双峰和多峰的不同模式。这些特征综合显示这些同层保存来自于不同生境的水生和陆生动物死于一些集群死亡事件。含化石层积上下层位中频繁出现的火山灰沉积揭示火山喷发导致了这些集群死亡事件。大量生物遗体被火山碎屑密度流或地表水带到附件的湖泊中快速埋藏形成了道虎沟地区的化石特异埋藏。同时，项目还对产于燕辽生物群和热河生物群的特异埋藏翼龙和鸟类化石的软组织开展了高精度地埋藏学、生物学和地球化学交叉研究，探讨了鸟类羽毛和后肢肌肉系统的演化。项目按照设计的研究计划开展了工作，完成了项目设计的研究目标。已发表标注项目资助SCI收录论文5篇，其他论文2篇。其中2篇论文分别发于顶级期刊Nature Communications和Nature Ecology & Evolution。项目资助培养研究生和博士后13人。部分研究成果被新闻媒体广泛报道，取得了良好的科普效应。