Plant-eating dinosaurs evolved backup teeth to eat tough food, research reveals

At the end of the Cretaceous, the duck-billed hadrosaurs were the most advanced herbivores on Earth. New research has revealed just how voracious these dinosaurs were, with their average tooth worn away in less than two months as they consumed enormous amounts of plants. Some of Earth's most successful herbivores may have had hundreds of thousands of teeth in their lifetime.