Megalodon probably had a major impact on the structure of marine communities . The fossil record indicates that it had a cosmopolitan distribution . It probably targeted large prey, such as whales , seals , and sea turtles . Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from the soft underside, megalodon probably used its strong jaws to break through the chest cavity and puncture the heart and lungs of its prey.