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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.

陆地的殖民化是生命史上的一个关键转折。分子钟分析表明，在古生代早期，陆地上节肢动物和植物的快速辐射与海洋中的寒武纪大爆发重叠，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来弥补化石记录中的这一空白，并为陆地生态系统的进化建立一个时间表。研究将采用低操作酸萃取法分离小碳质化石（SCFs）。对于很少变成化石的小生物来说，scf是一个独特的保存窗口。在20世纪80年代和90年代，已经报道了许多地球沉积物中的节肢动物scf，但此后一直被忽视。对煤球的初步分析表明，其特殊的SCFs适合与现存和古生代分类群进行比较。将使用地球化学技术测试有问题的SCFs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对博物馆收藏的theRhynie chert和Mazon Creek生物群中的节肢动物进行校正来补充。这些化石证据将为陆地化的新时间尺度提供一套强有力的校准，这将反过来成为检验关于陆地生命多样化驱动因素的假设的支柱。