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Was there a Cambrian explosion on land?

陆地上是否发生过寒武纪大爆发？

基本信息

批准号：
2885524
负责人：
金额：
--
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2885524
关键词：
Was there Cambrian explosion land

项目摘要

The colonisation of land was a key transition in the history of life. Molecular clock analyses imply a rapid radiation ofarthropods and plants on land in the early Palaeozoic, overlapping with the Cambrian explosion in the sea, but the fossilrecord is frustratingly limited. The project will combine palaeontological and computational methods to bridge this gap inthe fossil record and establish a timescale for the evolution of terrestrial ecosystems. Early Palaeozoic terrestrial depositswill be investigated using a low-manipulation acid extraction procedure to isolate small carbonaceous fossils (SCFs).SCFs are a unique preservation window for small organisms that rarely fossilise. Arthropod SCFs from numerousterrestrial deposits have been reported in the 1980 and 1990s but have been overlooked since. Preliminary analyses ofcoal balls reveal exceptional SCFs suitable for comparison with extant and Palaeozoic taxa. The phylogenetic positionand non-marine origin of problematic SCFs will be tested using geochemical techniques, providing reliable criteria forrecognising the oldest terrestrial ecosystems. The SCF record will be complemented by revising arthropods from theRhynie chert and Mazon Creek biotas in museum collections using tomography. This fossil evidence will provide a set ofrobust calibrations for a new timescale of terrestrialisation, which will in turn serve as a backbone for testing hypothesesabout the drivers of the diversification of life on land.

土地殖民化是生命史上的一个关键转变。分子钟分析表明，早古生代陆地上节肢动物和植物的快速辐射，与海洋中的寒武纪爆发重叠，但化石记录令人沮丧地有限。该项目将结合古生物学和计算方法，以弥补化石记录中的这一空白，并建立陆地生态系统演化的时间表。将使用低操作酸提取程序来研究早期古生代陆地沉积物，以分离小型碳质化石 (SCF)。SCF 是很少形成化石的小型生物体的独特保存窗口。来自大量陆地沉积物的节肢动物 SCF 在 1980 和 1990 年代已有报道，但此后一直被忽视。对煤球的初步分析揭示了特殊的 SCF，适合与现存和古生代类群进行比较。将使用地球化学技术测试有问题的SCF的系统发育位置和非海洋起源，为识别最古老的陆地生态系统提供可靠的标准。 SCF 记录将通过使用断层扫描技术修正博物馆收藏的雷尼燧石和马松溪生物群的节肢动物来补充。这些化石证据将为新的陆地化时间尺度提供一套强有力的校准，这反过来又将成为测试有关陆地生命多样化驱动因素的假设的支柱。