EAPSI: The Anatomy and Evolutionary Relationships of Klamelisaurus Gobiensis and Other Sauropod Dinosaurs of the Middle and Late Jurassic of China

蜥脚类恐龙是有史以来生活过的最大的陆地动物。蜥脚类恐龙的体型计划--以细长的脖子、巨大的身体和充满空气的骨骼为特征--出现在侏罗纪中晚期，其中一些进化的颈部长度超过9米。目前还不知道身体形态是如何以及为什么进化的。到目前为止，已发现的中国中、晚侏罗世蜥脚类化石不下20个。然而，大多数仍有待研究。通过与脊椎动物古生物研究所的许醒博士和恐龙进化方面的国际权威古人类学博士的合作，该项目将详尽地记录Klamelisaurus gobisis的解剖结构，Klamelisaurus gobisis是中国时代中晚侏罗世的一种未被研究的蜥脚类恐龙。来自Klamelisaurus和其他中国蜥脚类动物的新解剖学数据将被用来修正蜥脚类进化关系的假说，并阐明长颈进化的机制。Klamelisaurus gobiens的正型保留了基本完整的后颅骨骼。研究人员将花费EAPSI计划的很大一部分时间来制作克拉梅利龙的专题解剖学描述。此外，研究人员将通过一个大型形态特征矩阵重新评估蜥脚类动物的进化关系，其中包括许多从未被纳入此类分析的中国蜥脚类动物，特别是解决了Klamelisaurus是超长脖子Omeisauridae的早期成员的假设。在TNT和BEAST程序中，系统发育分析将在最大简约性和贝叶斯后验概率最优标准下进行。由此产生的进化树将被用于统计测试关于颈椎延长的不同进化假说的可能性，例如，在背部椎体颈化之前，颈椎前路的空气空间增加。该NSF EAPSI奖支持一名美国研究生的研究，并与中国科技部合作提供资金。

Sauropod dinosaurs are the largest terrestrial animals ever to have lived. The sauropod body plan--characterized by elongated necks, massive bodies, and air-filled bones--emerged in the Middle and Late Jurassic, some evolving neck lengths exceeding nine meters. It is not known how and why body forms evolve. So far, no fewer than twenty sauropods from the Middle and Late Jurassic of China were found. Yet most remain to be studied. Through collaboration with Dr. Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology, an international authority on dinosaur evolution, this project will exhaustively document the anatomy of Klamelisaurus gobiensis, an understudied sauropod from the Middle-Late Jurassic of China. New anatomical data from Klamelisaurus and other Chinese sauropods will be used to produce a revised hypothesis of sauropod evolutionary relationships and illuminate the mechanisms by which long necks evolved.The holotype of Klamelisaurus gobiensis preserves a largely complete postcranial skeleton. The researcher will spend a significant portion of the EAPSI program producing a monographic anatomical description of Klamelisaurus. In addition, the researcher will reassess sauropod evolutionary relationships with a large morphological character matrix that includes numerous Chinese sauropods that have never been included in such an analysis, specifically addressing the hypothesis that Klamelisaurus is an early member of the exceptionally long-necked Omeisauridae. Phylogenetic analyses will be performed under both maximum parsimony and Bayesian posterior probability optimality criteria in the programs TNT and BEAST. The resulting evolutionary trees will be used to statistically test the likelihood of different evolutionary hypotheses regarding neck elongation, e.g., air space increases in anterior cervical vertebrae prior to the cervicalization of dorsal vertebrae. This NSF EAPSI award supports the research of a U.S. graduate student and is funded in collaboration with the Chinese Ministry of Science and Technology.