Iguanodon is a genus of ornithopod dinosaur that existed during the early Cretaceous period, around 130-125 million years ago. Its name means “iguana tooth,” due to the similarity of the teeth to those of an iguana.

Iguanodon was a herbivorous dinosaur and could grow up to 30 feet long and weigh around 4-5 tons. It had a large thumb spike on its hands which it may have used for defense, and a smaller thumb spike on its feet. The Iguanodon also had a long, stiff tail, which it probably used for balance. Iguanodon is one of the first dinosaurs to be named and one of the best-known dinosaurs of the early Cretaceous.