Eastern Chinese Provinces
The Jehol Biota contains probably the most prolific fossil producing strata in China. It is found within the Eastern Provinces, forming a complex and heavily folded sediment which shows poor conformity across the regions. For this reason, the dating and comparison of fossils is difficult at different geographical points in the sediments.
These deposits, along with the Daohugou Beds, which sit stratigraphically below the Jehol levels have produced significant pterosaur specimens that have enhanced the understanding of this fossil group considerably.