New sauropod remains from the Middle Jurassic Dongdaqiao Formation of Qamdo, eastern Tibet

Abstract

We report isolated postcranial materials newly excavated from the Middle Jurassic Dongdaqiao Formation in Chaya County, Qamdo City, eastern Tibet. The specimens are assignable to Eusauropoda based on the following combination of characters: huge size of caudal vertebrae and humeral shaft, weakly developed amphicoelous caudal centrum, femoral distal ends with two condyles and a shallow intercondylar groove, and rod-like transverse process of the anterior caudal vertebra with its base not extending to the neural arch. Due to the fragmentary nature of the specimens, we refrain from assigning them to lower taxonomic levels or new species of sauropod until more complete materials are excavated from Qamdo. Nevertheless, the new materials from Qamdo demonstrate that some gigantic sauropods migrated to eastern Tibet during the Middle Jurassic and were more widely distributed than previously known.