Early Cambrian biogeography and the diversification center of Cambrian bioradiation in the Palasian Ocean

寒武纪生物辐射是地球历史上一次重大的生物革命。这一事件可能是由地球的构造演化和寒武纪初一块超级大陆的解体引发的。然而，现有的古地理重建是相互矛盾的，对最早寒武纪的古生物地理学缺乏详细的研究。该项目旨在通过研究中亚造山带(CAOB)扎扎布汗和图瓦-蒙古微大陆(均为蒙古)的小型骨骼动物群(SSFS)来调查早寒武世古生物地理。生物统计分析将揭示早寒武世不同阶段特定SSFS组的古生物地理模式、特有种和动物区系省。为实现这一目标，将建立一个关于寒武纪帕拉西亚海洋SSF时空分布的数据库，该数据库将以全球SSF发生的文献数据为补充。拟议项目的关键是评估已发表的主要古大陆最早寒武纪的古地理重建，讨论潜在的洋流和动物群扩散路线和速率，以及早寒武世特有的程度。如果地理物种形成在寒武纪生物辐射事件中发挥了主要作用，如果蒙古微洲是作为寒武纪生物辐射期间生物多样性发展热点的热带群岛的一部分，则应得出结论。为进一步支持古生物地理分析和古地理评价，利用碎屑锆石U-Pb测年和Lu-Hf同位素分析相结合的方法，研究了蒙古微大陆寒武系砂岩的物源。

The Cambrian Bioradiation represents one of the major biotic revolutions in Earth history. This event may have been triggered by the tectonic evolution of Earth and the breakup of a supercontinent at the beginning of Cambrian. However, the existing palaeogeogeographic reconstructions are contradictionary and detailed investigations on the palaeobiogeography of the earliest Cambrian are lacking. The proposed project aims at the investigation of the early Cambrian palaeobiogeography by the study of small skeletal faunas (SSFs) of the Dzabkhan and Tuva-Mongolia micro-continents (both Mongolia) of the Central Asian Orogeny Belt (CAOB). Biostatistical analyses shall reveal palaeobiogeographic pattern, endemism and faunal provinces of the specific groups of SSFs for the different stages of early Cambrian. To achieve this a database on the temporal and spatial distribution of SSFs in the Cambrian Palasian Ocean will be set up, which will be complemented by literature data of global SSF occurrences. Key to the proposed project is to evaluate the published palaeogeographic reconstructions of major palaeocontinents for the earliest Cambrian, discuss potential ocean currents and faunal dispersion routes and rates as well as the extent of endemism in the early Cambrian. Conclusions shall be drawn if geographic speciation played a major role during the Cambrian Bioradiation Event and if the Mongolian micro-continents were part of a tropical archipelago, which served as hotspot for developing biodiversity during the Cambrian bioradiation. To further support the palaeobiogeographic analysis and evaluation of palaeogeography it is aimed to investigate the provenances of some specific Cambrian sandstones from the Mongolian micro-continents by using combined U-Pb age dating and Lu-Hf isotope analyses on detrital zircon grains.