Large scale dinoturbation in braided stream deposits: evidence from the Cretaceous Tugulu Group of the Hami area, Eastern Xinjiang, China

Abstract

Large dinosaur tracks were recently reported from locations in the Pterosaur-Yadan National Geological Park situated about 100 km south of Hami in Xinjiang Province, China. The park comprises a substantial area in a much larger arid region comprising and extensive spectrum of Cretaceous, siliciclastic, Tugulu Group, lithofacies representing proximal, basin margin, alluvial fan and braided stream deposits, grading into alluvial plain, deltaic and lacustrine facies near the depocenter. Due to the difficulties of conducting detailed geological surveys in such a vast and inhospitable area, definitive resolution of the litho-, bio- and chrono-stratigraphy is challenging in some areas, and yet to be published in detail. Nevertheless, the occurrence of large dinosaur tracks and dinoturbated units, here interpreted as sauropodan, in association with root casts, dinosaur bone and fossil wood, points to the potential of this frontier area to yield valuable paleontological information, and show that flora and fauna were found in arid braided stream systems away from the lacustrine depocenters where body fossils are more abundant and better known.