Collaborative Research: Neosuchian Evolution and Crocodylian Origins - 190 Million Years of Biodiversity and Biogeographic Response to Climate and Tectonics

这项研究的重点是新苏珊瑚的进化史？活着的鳄鱼、鳄鱼和食人鱼--以及它们已灭绝的近亲。新石器时代在每一块大陆上都有丰富的化石记录，时间跨度近2亿年。令人惊讶的是，它们种类繁多，包括长着鳍状肢和鲨鱼尾巴的海洋动物，长着铁锤般的牙齿的小型碾压动物，以及30多只脚巨人。新苏珊瑚的进化和多样性的许多方面尚不清楚。这包括灭绝物种的确切数量，几个谱系的相互关系，现代鳄鱼的地理起源，以及包括气候和海平面变化在内的大规模地球变化在形成新苏珊瑚生物多样性中所起的作用。研究人员将检查世界各地博物馆收藏的标本，包括化石和现代物种的骨骼，以汇编一部从起源到现在的全面、准确的新苏珊瑚历史。新苏珊瑚是少数几个我们可以同时从每个活着的物种收集数据并用化石采集大量已灭绝多样性的动物群体之一。该项目将进一步发展使用新苏珊瑚作为研究模型组，探索和调和来自活物种和灭绝物种的数据之间的冲突。这反过来又将改进用于从分子数据估计分歧时间的技术--这是现代生命科学的核心。由于它们在全球的分布，新苏珊瑚还将使我们能够探索在很长一段时间内多样性与气候的相互关系。反过来，这将改善保护现代鳄鱼物种的战略，其中一些物种处于严重濒危状态。

This research focuses on the evolutionary history of neosuchians ? living alligators, crocodiles, and gharials -- and their closest extinct relatives. Neosuchians have a rich fossil record on every continent spanning almost 200 million years. They were surprisingly diverse, including seagoing animals with flippers and sharklike tails, small crushing forms with anvil-like teeth, and 30+ foot giants. Many aspects of neosuchian evolution and diversity are unclear. This includes the exact number of extinct species, the interrelationships of the several lineages, the geographic origins of modern crocodylians, and the role large-scale earth changes, including changes in climate and sea level, played in shaping neosuchian biodiversity. The investigators will examine specimens in museum collections around the world, including fossils and the skeletons of modern species, to assemble a comprehensive, precise history of neosuchians from their origins to the present.Neosuchians are one of the few groups of animals for which we can simultaneously collect data from every living species and sample a substantial amount of extinct diversity with fossils. This project will further develop the use of neosuchians as a model group for studies exploring and reconciling conflicts between data from living and extinct species. This, in turn, will improve techniques used to estimate divergence time from molecular data - something central to the modern life sciences. Because of their global distribution, neosuchians will also allow us to explore the interrelationships of diversity and climate over very long time periods. This, in turn, will improve strategies to conserve modern crocodylian species, some of which are gravely endangered.