The Phylogenetic Relationships and Ecomorphological Diversification of Early Crocodylomorphs

地球上生物的多样性在时间和生命之树上的分布是不均匀的。对支撑这一观察的动力学和过程的理解是进化生物学领域的核心问题之一。鳄形类（Crocodylomorphs）是一组伪鳄目的主龙类，包括鳄形类及其已灭绝的亲属，在今天表现出有限的分类和形态多样性;然而，现存的形式仅代表该群体在其大约2.3亿年的历史中所取得的多样性的一小部分。鳄形类占据了各种生态，进化出不同的形态，并在两次大灭绝事件中幸存下来。这使得它们成为研究宏观进化过程的一个很好的系统;然而，一个解决好的系统发生是必要的，以便能够有效地做到这一点。在鳄形目中，早期鳄形目（“Shenosuchia”+ Protosuchia）的进化关系知之甚少，海鳄目的位置也是如此。因此，本项目将通过建立和分析新的系统发育数据集，包括编制一份附有插图的字符表，设法解决这一问题。该项目将整合来自广泛分类群的第一手观察数据，并利用CT扫描技术研究和表征标本的内部解剖结构。将应用由此产生的遗传学，进行颅和颅后差异分析，以更好地了解整个三叠纪/侏罗纪边界组的生态形态辐射。这样做将允许灭绝的选择性和大规模灭绝事件的恢复力被确定，对当今的保护工作的潜在影响。

The diversity of organisms on Earth is unevenly distributed across time and the tree of life. An understanding of the dynamics and processes underpinning this observation is one of the central questions in the field of evolutionary biology. Crocodylomorphs, a group of pseudosuchian archosaurs that includes crocodilians and their extinct relatives, exhibit limited taxonomic and morphological diversity in the present day; however, extant forms represent only a fraction of the diversity achieved by the group throughout their around 230-million-year history. Crocodylomorphs have occupied a variety of ecologies, evolved a disparate range of morphologies, and survived two mass extinction events. This makes them an excellent system through which to study macroevolutionary processes; however, a well-resolved phylogeny is necessary to be able to effectively do so. Within Crocodylomorpha, the evolutionary relationships of 'early crocodylomorphs' ("Shenosuchia" + Protosuchia) are poorly known, as is the position of the thalattosuchians. As such, this project will seek to address this issue through the construction and analysis of a new phylogenetic dataset, including the development of an illustrated character list. This project will incorporate data from first-hand observation of a wide range of taxa and utilise CT scanning technology to study and characterize the internal anatomy of specimens. The resultant phylogeny will be applied, conducting cranial and post-cranial disparity analyses to better understand the group's ecomorphological radiation across the Triassic/Jurassic boundary. Doing so will allow for extinction selectivity and resilience to mass extinction events to be determined, with potential implications for present-day conservation efforts.