Ever wonder why sharks have so many differently shaped teeth or why they keep regrowing throughout their lives? Dr. David ...

Genevieve Formation, where the McGinnis’ nail tooth shark was found, is where more than 70 species of sharks and other fish have been identified. Located along the southern border of Kentucky ...

A rendering of Clavusodens mcginnisi, or “McGinnis’ nail tooth,” an ancient shark that stalked the ocean floor 340 million years ago. Rendering courtesy of the National Park Service A shark ...

This “chipmunk shark” packed quite a punch with its strange set of teeth. Its diet varied from shrimp to worms to hard-shelled brachiopods — generally crunchy things. The discovery ...

Scientists have found ancient nail tooth shark fossils deep inside Mammoth Cave in Kentucky, revealing new information about a mysterious group of extinct predators.

Turns out, the palm-sized tooth belonged to an animal that died at least 3.5 million years ago: an Otodus megalodon shark. "She told me she was wading in knee-deep water when she saw it and dove ...