It is a genus of Pliosaurs, which were large, carnivorous marine reptiles that lived during the Mid to Late Jurassic Period (c. 160 million to 155 million years ago)
Four strong paddle-like limbs suggest that Liopleurodon was a powerful swimmer. Its four-flipper mode of propulsion is characteristic of all plesiosaurs. A study involving a swimming robot has demonstrated that although this form of propulsion is not especially efficient, it provides very good acceleration - a desirable character in a predator. Studies of the skull have showed that it could probably scan the water with its nostrils to ascertain the source of certain smells. Liopleurodon was carnivorous and it is unlikely that it had many, if any, predators.