Liopleurodon ferox

Liopleurodon, a massive marine reptile from the Middle Jurassic period, was a formidable predator that could grow up to 25 meters in length, belonging to the family Pliosauridae, a group of short-necked, large-headed plesiosaurs; its powerful, crocodile-like jaws, lined with sharp teeth, were well-suited for capturing and consuming large prey, including fish, marine reptiles, and possibly even smaller dinosaurs, while its streamlined body, with robust flippers and a tail adapted for propulsion, allowed it to swiftly dominate the seas of ancient Europe.
Liopleurodon's impressive size and strength, combined with its acute sensory adaptations, made it one of the ocean's apex predators during the Jurassic, hunting in deep, coastal waters where it would have likely competed with other large marine reptiles like the long-necked Elasmosaurus and the giant fish Ichthyosaurs.
Its fossils, often found in what is now the United Kingdom, reveal an animal that was not only a top predator but also highly adapted to a fully aquatic lifestyle, capable of fast, powerful movements in pursuit of its prey.