Late Palaeozoic Tetrapod Biogeography

晚古生代是陆地脊椎动物生态系统发展和组织的关键时期。正是在这个时候，更复杂的社区结构与错综复杂的营养层次建立在陆地领域。此外，最早的进化和多样化的类人猿（完全陆生的四足动物）出现了两个分支：Synapsida（包括哺乳动物）和Sauropsida（包括爬行动物和鸟类）。晚石炭世和早二叠世生态系统主要集中在潮湿的赤道热带带的水边栖息地。然而，在早二叠世末期，陆地环境的重大变化始于南极冰盖的消融，导致气候变化，如热带常湿带的减少和最终丧失。沿着，陆地生态系统首次从古赤道地区扩展到高纬度季节性温带地区。虽然这些地理模式是已知的，他们从来没有被调查在一个严格的定量框架。本研究将以支序分类法来验证四足动物早期分类模式的某些假说。为此目的，从俄罗斯和北美选择的关键四足动物类群将进行分类学重新评估，并纳入全球系统发育分析，以检查基础的关系。此外，将更新现有的南非卡鲁盆地四足动物标本数据库。将对地方和全球数据库进行进一步的定量分析，以调查盆地内和盆地之间的省界性，以及地质时期动物区系同质性的变化。这项研究的结果将对理解四足动物，特别是完全陆生的四足动物的早期地理历史具有重要意义。

The late Palaeozoic represents a crucial period in the development and organisation of terrestrial vertebrate ecosystems. It was at this time that more complex community structures with intricate trophic hierarchies were established in the terrestrial realm. Moreover, the earliest evolution and diversification of amniotes (fully terrestrial tetrapods) occurred with the bifurcation into the two lineages: Synapsida (including mammals) and Sauropsida (including reptiles and birds). Late Carboniferous and Early Permian ecosystems were mostly centred on waterside habitats in a humid equatorial tropical belt. However, towards the end of the Early Permian, substantial changes in terrestrial environments began with the deglaciation of the ice cap at the South Pole leading to climate changes such as the reduction and eventual loss of the tropical everwet belt. Along with this, terrestrial ecosystems for the first time expanded away from the palaeoequatorial regions and into the higher latitude seasonal temperate regions. Although these biogeographic patterns are known, they have never been investigated in a rigorous quantitative framework. The proposed study will test certain hypotheses regarding the early patterns of tetrapod biogeography with cladistic biogeographic methods. For this purpose, selected critical tetrapod taxa from Russia and North America will be taxonomically re-evaluated and included into global phylogenetic analyses to examine the relationships of basal amniotes. In addition, an existing database of tetrapod specimens from the Karoo Basin of South Africa will be updated. Further quantitative analyses will be carried out on both local and global databases to investigate provinciality within and between basins, and the changes in faunal homogeneity through geological time. The results of this research will have important implications for understanding the early biogeographic history of tetrapods and specifically the fully terrestrial amniotes.