Squalicorax

Geologic age: 90–100 million years ago, Cretaceous Period

Region in Minnesota: Mesabi Iron Range

Fast fact: This extinct shark was abundant in the ancient seaway that spread across the middle of North America during much of the Age of the Dinosaurs. The serrated edges on its teeth mean that Squalicorax was eating prey too big to fit in its jaws, which tells us it preferred larger prey. Tooth marks of Squalicorax have been found on bones of dinosaurs, flying reptiles, fish, and marine reptiles.