Geographic and geologic map showing the location and involved strata of the studied fossil sites in the Xinhe Formation. (A, B) location of the fossiliferous localities in the Gansu Province. (C) Geological map of the involved strata of the studied fossil site (from State Bureau of Surveying and Mapping, GS (2016)2884). White star=Jinchuanloong niedu. Black star=plesiosaur fossils. (D) Stratigraphic chart of the Jurassic at the localities.