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

Moore Andrew J, Washington DC

Investigators

Abstract

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.