蜥脚类恐龙起源和早期演化

Sauropodomorphs include sauropods and their close relatives, and are the sister group of theropods. They represent two distinctive evolutionary trends of dinosaurs: sauropodomorphs include the largest animals ever walked on Earth, while theropods are still alive by flying birds. However, little is known on the initial stage of sauropodomorph gigantism, corresponding to the origin and early evolution of sauropods, mainly due to lack of relevant key fossils. Even Yunnan and Sichuan provinces of China preserve the best relevant fossil records in the world (The mid-Early Jurassic Lufeng dinosaur fauna and the mid-Middle Jurassic Zigong Dashanpu dinosaur fauna), few have been recovered in-between around the Early/Middle Jurassic boundary, which is the crucial stage for the origin and early evolution of sauropods. This project will be based on two new important discoveries from Huili of Sichuan and Yuanmou of Yunnan, explore new material in this area, study the anatomy of new specimens, analysis their phylogenetic relationships, and discuss the potential relationships between the origin and early evolution of sauropod dinosaurs and paleoenvironmental changes. This will be an important contribution to dinosaur research as well as to the development of Chinese paleontology.

蜥脚类和其近亲构成的蜥脚型类是兽脚类的姊妹群，它们代表了恐龙演化的两个截然不同的方向：巨型化的蜥脚型类包括了迄今为止地球上行走过的最大动物，而小型化的兽脚类（鸟类）一直繁衍至今。然而对巨型化的初始阶段，也即蜥脚类的起源和早期演化研究却很薄弱，主要原因是相关化石的匮乏。即便我国云南四川发现了世界上保存最好的早-中侏罗世的相关化石记录（早侏罗世中期以基干蜥脚型类为代表的禄丰恐龙动物群和中侏罗世中期以真蜥脚类为代表的自贡大山铺恐龙动物群），两者之间却鲜有化石记录，而这对应的正是蜥脚类恐龙起源和早期演化的关键阶段。本项研究拟基于新近发现的川滇过渡区（四川会理和云南元谋）早侏罗世晚期保存较好的两件难得的相关标本，对这一问题进行综合研究，包括新化石的探寻、标本骨骼学记述、新属种系统发育关系分析以及对蜥脚类起源和早期演化与环境变化潜在相关性的探讨。这将是对恐龙研究和我国古生物学发展的重要贡献。

本项研究的主题是蜥脚类恐龙的起源和早期演化，目标是要发现一批新的有价值的恐龙化石，研究一批相关恐龙化石及其系统发育关系，揭示蜥脚类恐龙起源和早期演化在骨骼学特征上的转变过程，并探讨这一过程的内外机制。在项目支持下，我们发现了一批恐龙化石，尤其是在云南楚雄武定县万德镇发现了一个早侏罗世早期的恐龙富集点，这很可能是我国目前已知最早的恐龙骨骼化石点，对研究中国恐龙演化具有重要意义，相关研究工作正在进行。.我们重点研究了云南、四川、重庆、新疆和河南的若干蜥脚型类恐龙。研究了云南禄丰早侏罗世的恐龙，发表了两篇文章，分别对早期分化蜥脚型类的金山龙和星宿龙进行了深入研究。研究了四川自贡大山铺保存的大山铺龙，发表了两篇文章，对新蜥脚类起源和早期演化做出了贡献。研究了重庆云阳中侏罗世发现的峨嵋龙一新种，并研究了同地保存的蜥脚类病例现象。研究了河南白垩世一蜥脚类恐龙牙齿替换现象。详细研究了新疆鄯善晚侏罗世新疆巨龙的背椎骨骼。