Sea Monsters Sea Monsters Basilosaurus A large swimming whale from the late Eocene that fed on other whales and sharks! 5893494 Megalodon and Mosasaurus This picture is impossible as Megalodon lived millions of years after Mosasaurus. Unless it's Cretoxyrhina... 5893495 Icthyosaurus Icthyosaurs lived in groups which is helpful at spotting predators. 5893496 Icthyosaurus 2 Icthyosaurs probably leaped out of the water like dolphins. 5893497 Mosasaurus This formidable killer was the king of the ocean in the Cretaceous era. 5893508 Mosasaurus 2 A Mosasaurus is about to snatch a swimming sea bird called Hesperonis. 5893509 Tylosaurus Tylosaurus was the largest of the Mosasaurs and grew to 14m in length! 5893510 Kronosaurus A Pliosaur from Australia sealing the fate of a turtle. 5893511 Elasmosaurus, Icthyosaurus and Metriorynchus Elasmosaurus was a long necked reptile that hunted fish while Metriorynchus was a sea crocodile that also hunted fish. 5893557 Plesiosaurus and Tylosaurus A Tylosaurus launches out of the water to grab an unsuspecting Plesiosaurus 6038702