To trace tusk evolution, researchers needed a more concrete definition to distinguish tusks from teeth and other external ...

Hundreds of millions of years ago, fish had sensory features on their exoskeletons that contained dentine, the material that makes our teeth sensitive today ...

Sharks, skates and catfish also have tooth-like structures called denticles that make their skin feel like sandpaper. When Haridy studied the tissues of her catfish, she saw that the denticles were ...