Ichthyosaur is the Greek word for 'fish lizard'. For tens of millions of years ichthyosaurs were the masters of the oceans. Then they became extinct and their place was taken by the plesiosaurs.

Their shape may remind you of a fish and a dolphin, but they were in no way related. Ichthyosaurs were not large by ancient lizard standards, being under 4m long. Their streamlined shape probably allowed them to swim at 40km/hr. Like all lizards, they breathed air and so had to keep coming to the surface.