The dinosaur with 500 teeth is called Nigersaurus. This dinosaur had a long neck and a snout that was extremely wide and straight-edged, and it had more than 500 teeth that could be replaced. The teeth were arranged in dental batteries, which erupted in unison, and each tooth was replaced once every 14 days. Nigersaurus wore its tooth crowns down faster than other dinosaurian herbivores, and its tooth replacement rate was the highest of any known dinosaur.