The dinosaur with 500 teeth is 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. Its tooth crowns wore down faster than other dinosaurian herbivores, and its tooth replacement rate was the highest of any known dinosaur. The original fossil skull of Nigersaurus is one of the first dinosaur skulls to be digitally reconstructed from CT scans.