Collaborative Research: Ecomorphological diversification and the origin of phenotypic disparity in crocodile-line archosaurs

物种形态通常会进化以满足环境的要求。在化石记录中，以及在现存物种中，大的形态变化经常与栖息地或生态的变化有关。然而，人们对控制与生态变化相关的形态变化的一般规则仍然知之甚少。该项目将使用骨骼和软组织解剖学以及详细的3D形状数据来研究密切相关的过渡物种，以调查长寿且化石丰富的鳄形目(鳄鱼、鳄鱼及其已灭绝的近亲)的形态和生态进化。该项目将利用该小组对极端环境进行的多项自然实验，为主要的生态和形态转变开发详细的概念模型，以了解形态变化的潜在规律。然后，这些模型将作为如何以及为什么发生变化的预测值，这可以在具有类似叙述的其他组中进行测试。重要的例子包括四足脊椎动物最初出现在陆地上，鸟类如何登上天空，以及哺乳动物统治的第一步。这项研究的创新技术、技术和广泛适用的结论将促进古生物学家、生物机械学家、生态学家和进化生物学家之间的跨学科工作。研究人员将使他们的数据、数字模型、分析工具和必要的补充文件广泛可用。此外，该项目将支持相关的博士和博士后研究，并促进显著低于代表性的群体接受高等教育的机会。该项目将使用综合方法来揭示重大进化转变中生态形态变化的复杂性。这项研究将研究新环境如何对历史表型提出新的、往往是极端的要求，方法是解决大规模栖息地和生态转变如何推动多个集成解剖系统的进化。这项研究将在进化规模上测试关于表型整合的假设，以确定发育速度、序列异时性和/或模块化模式是否决定了持续应用的生态形态多样化规则是否构成了适应性辐射的基础。其结果将是一个史无前例的鳄鱼形态颅骨和后颅骨多样性数据库，其中包括增强对比的神经和骨骼组织，原始和分割的CT堆栈，3D数字模型，以及捕食性脊椎动物如何转移到海岸线上、海洋中和食草动物的比较的分支内概念模型。MicroCT和尖端的、可扩散的基于碘的对比增强计算机断层扫描成像，以及用于使用最新的系统发生学方法分析进化趋势的稳健的形态发展史，代表了该研究小组开发的潜在的变革性方法。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Species morphology typically evolves to meet the demands of the environment. In the fossil record, and among existing species, large morphological changes are frequently associated with changes in habitat or ecology. However, there remains little understanding of the general rules that govern morphological change associated with ecological change. This project will use skeletal and soft-tissue anatomy as well as detailed 3D shape data to study closely-related, transitional species to investigate the evolution of morphology and ecology in the long-lived and fossil-rich group Crocodylomorpha (crocodiles, alligators, and their extinct relatives). The project will exploit the group's multiple natural experimentation with extreme environments to develop detailed conceptual models for major ecological and morphological transitions that will inform on the rules underlying morphological change. These models will then serve as predictors for how and why transformations occur, which can be tested in other groups with similar narratives. Important examples include the initial emergence of four-limbed vertebrates onto land, how birds took the sky, and the first steps in the reign of mammals. The innovative technologies, techniques, and widely applicable conclusions from this research will promote interdisciplinary work among paleontologists, biomechanists, ecologists, and evolutionary biologists. The researchers will make their data, digital models, analytical tools, and essential supplementary files available for wide access. Furthermore, this project will support associated PhD and Postdoctoral research as well as foster access to higher education for substantially underrepresented groups.This project will use integrative approaches to reveal the complexities of ecomorphological changes across major evolutionary transitions. The study will examine how novel environments put new, often extreme demands on historical phenotypes by addressing how large-scale habitat and ecological transitions drive evolution across multiple integrated anatomical systems. The research will test hypotheses about phenotypic integration on an evolutionary scale to determine whether developmental rates, sequence heterochrony, and/or patterns of modularity determine if consistently applied rules of ecomorphological diversification underlie adaptive radiations. The outcome will be an unprecedented database of crocodylomorph cranial and post-cranial diversity that includes contrast-enhanced neural and skeletal tissues, raw and partitioned CT stacks, and 3D digital models as well as comparative, intra-clade conceptual models for how predatory vertebrates shift to lives on the shoreline, within the sea, and toward herbivory. The microCT and cutting-edge, diffusible iodine-based contrast-enhanced computed tomography imaging, in addition to a robust morphological phylogeny for analysis of evolutionary trends using the latest phylogenetic methods, represent potentially transformative methodologies developed by this research group.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.