Deep in the heart of northern Kansas, researchers excavated farmland that used to be under the ocean and ended up finding a brand new species of shark that lurked beneath the surface around 91 million years ago.

During the middle to the late Cretaceous period, the region of the United States we know now as the Great Plains was submerged under the North American Western Interior Seaway, with Mitchell County, Kansas lying at the edge of the eastern boundary of the water.

Researchers excavate a farm in Kansas where the Credotus teeth were found. Image via DePaul University.

Just as the oceans are teeming with life today, so too did the ancient seaway. And also like today, sharks were an apex predator that most marine animals...