For all the success of dinosaurs on land, they never made it into the sea - that is the realm of an entirely different group of reptiles, no less successful and no less awesome. The Jurassic sea boasts the largest carnivore on the planet: Liopluerodon, at 25 meters, this monster was the same size as a blue whale, but armed with teeth that were a quarter of a meter long. And Ophthalmosaurus - fasted animal in the sea with huge eyes for night time hunting.