Late Palaeozoic Tetrapod Biogeography

晚古生代是陆生脊椎动物生态系统发育和组织的关键时期。正是在这个时候，在陆地领域建立了更复杂的群落结构和复杂的营养等级。此外，羊膜动物（完全陆生四足动物）最早的进化和多样化发生在两个分支：新孔门（包括哺乳动物）和蜥脚类（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湿润的赤道热带水边生境。然而，在早二叠纪末期，随着南极冰盖的消融，陆地环境开始发生实质性变化，导致气候变化，如热带常湿带的减少和最终消失。与此同时，陆地生态系统第一次从古赤道地区扩展到高纬度的季节性温带地区。虽然这些生物地理模式是已知的，但它们从未在严格的定量框架中进行过调查。本研究将用进化生物地理学的方法检验关于四足动物早期生物地理学模式的某些假设。为此，我们将对来自俄罗斯和北美的关键四足动物类群进行分类重新评估，并将其纳入全球系统发育分析，以研究基础羊膜动物的关系。此外，将更新来自南非卡鲁盆地的现有四足动物标本数据库。进一步的定量分析将在本地和全球数据库上进行，以调查盆地内部和盆地之间的省际性，以及随着地质时间的推移动物均匀性的变化。本研究结果将对了解四足动物，特别是全陆生羊膜动物的早期生物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.