Ichthyosaurs were large marine reptiles that lived from the late Triassic into the early Jurassic period. The Ichthyosaur jaw was long relative to the size of the animal and contained many sharp teeth, making it a fearsome predator. This partial fossil of a jaw is from early Jurassic deposits near Lyme Regis on the Dorset coast of south England. Actual length is 210 mm.