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I recently acquired three tooth fossils from southwestern China initially labeled as a "Plesiosaurus indet." tooth. The specific locality of the tooth fossils is the Lower Shaximiao Formation, Zigong, Sichuan, China. The age of the Lower Shaximiao formation ranges from Early to Middle Jurassic. The only known plesiosaur species from the Shaximiao formation is Bishanopliosaurus zigongensis, a rhomaleosaurus. If these three tooth are indeed identified as a plesiosaur tooth, they probably belong to Bishanopliosaurus sp. Can anyone help me to identify whether these teeth are plesiosaur teeth?

While the Triassic deposits of southern China (incl. Tibet) have yielded a plethora of marine reptiles closely related to plesiosaurs, it's quite ironic that only a handful of plesiosaurs have been found in post-Triassic deposits in China. As far as I'm aware, Bishanopliosaurus, Yuzhoupliosaurus, and Sinopliosaurus* are the only Chinese plesiosaurs from post-Triassic rocks and they haven't been studied lately. Is it possible that the paucity of Jurassic plesiosaurs in China could be due to the limited exposures of Jurassic-aged marginal marine sediments in China (there aren't any Cretaceous-aged marine sediments in China that I'm aware of)? *Sinopliosaurus weiyuanensis Young, 1944 was named on the basis of disarticulated skeletal elements from the Early Jurassic, including an ischium, femur, a tooth, and some vertebrae. However, Young himself changed his mind about the association of the elements in the Sinopliosaurus hypodigm, restricting Sinopliosaurus to the femur and ischium and assigning the tooth and vertebrae to the teleosaur Peipehsuchus. In any case, the lectotype femur and ischium of Sinopliosaurus do not appear to sufficient grounds for creating a new taxon, and Sinopliosaurus is a nomen dubium known only from the Early Jurassic (Buffetaut et. al. 2008). The only other nominal species of Sinopliosaurus, S. fusuiensis (of Early Cretaceous age), is a spinosaurid and not a plesiosaur, as pointed out by Buffetaut et. al. Buffetaut, E.; Suteethorn, V.; Tong, H.; and Amiot, R. (2008). "An Early Cretaceous spinosaur theropod from southern China". Geological Magazine 145 (5): 745–748.doi:10.1017/S0016756808005360.