While Galagadon lived alongside T. rex and Triceratops around 67 million years ago, it's not exactly the kind of colossal beast you'd find Jason Statham battling in a big-budget movie. This shark was about 30-45 cm long, and its distinctive teeth measure less than a millimeter across. It's actually related to modern-day carpet sharks.

North Carolina State University lecturer Terry Gates and volunteer Karen Nordquist (after whom the creature is also named) meticulously sifted through two tons of sediment left after the discovery of famous T. rex specimen Sue in South Dakota. They found more than two dozen Galagadon teeth.

"It amazes me that we can find microscopic shark teeth sitting right beside the bones of the largest predators of all time," said Gates, a co-author of a paper on the shark that was published this week in the Journal of Paleontology. "These teeth are the size of a sand grain. Without a microscope you'd just throw them away."