Video from National Geographic
Last August, scientists sponsored by Ohio University uncovered a new species of reptile that lived about 100 million years ago. While it's technically a crocodile, this ancient lizard, Pakasuchus, had multiple types of teeth. Most reptiles have just one type of tooth. Most mammals possess several different types of teeth (incisors, canines, bicuspids, molars etc.)
To learn more, click here.