Triassic Period, 250 million years BP. A complete Keichousaurus hui fossil in a matrix. 2.3 kg, 29cm (11 1/2"). From an old Bristol paleontological collection; acquired 1950s-1960s; from Xingyi, Guizhou, China. Keichousaurus was a late-Triassic marine reptile, and a member of the Pleurosaur family, and went extinct 250 million years ago during the Triassic-Jurassic extinction event. They were specialised fish eaters, and were highly unusual amongst marine reptiles in that they gave birth to live young rather than laying eggs.