Which dinosaur was named for its iguana-like teeth?

The dinosaur named for its iguana-like teeth was Iguanodon. English geologist Gideon Mantell chose the name because the fossil teeth resembled those of a modern iguana, although Iguanodon’s teeth were much larger and belonged to a very different animal.

The name combines “iguana” with the Greek odon, meaning “tooth.” Mantell studied fossils found in southern England and announced the animal in the 1820s. At first, the creature was difficult to reconstruct, and early restorations placed its distinctive conical thumb spike on the nose instead of on the hand.

Iguanodon was a large herbivorous ornithopod that lived during the Early Cretaceous, approximately 126–122 million years ago. It had a toothless beak, rows of cheek teeth for processing plants, a long grasping fifth finger, and a pointed thumb that may have helped with defense.

The name does not mean that Iguanodon was closely related to iguanas. It refers only to the resemblance of the teeth. Camarasaurus, Hadrosaurus, and Megalosaurus have different names and do not provide the same “iguana-tooth” origin.