Xiphactinus (name meaning "Swift Shark"), often nicknamed the "Bulldog Fish", is a genus of large predatory bony fish that originated during the Late Cretaceous period in what is now North America, Europe, and Australia. Famous for its ugly appearance, it would have been in a middling role in the marine food chain.
Thought to have been extinct for 65 million years, there are still some that remain alive on Primeval Island.