Ophthalmosaurus was an icthyosaur that existed in the Jurassic era, 165-150 million years ago to be precise. Even for an icthyosaur, it was fast. It also had large eyes, the largest of any known marine reptile, giving it good vision. It could reach 5 metres in length and was a favourite food of Liopleurodon, when it could catch it.The opthalmosaurusalso gave birth to live young.It fed on squids and fish. Several beautiful preserved fossils have been found.