Brevicaudosaurus

Brevicaudosaurus is an extinct genus of marine sauropterygians from the Middle Triassic of China. The genus contains a single species, Brevicaudosaurus jiyangshanensis. It was a small animal; the holotype specimen measures approximately 58.8 centimetres (23.1 in) in total length. The body is broad and flat, with an unusually short and flattened tail compared to other related taxa, which indicates that it likely could not swim quickly and may have been a benthic carnivore. A juvenile specimen, about one-third the length of adult individuals, was described in 2025. In contrast to the fanglike teeth in the mature skulls, the teeth are small and conical in the juvenile.