- An American herbivorous dinosaur of good size, allied towards iguanodon. It's found in the Cretaceous formation.
- A genus of dinosaurian reptiles, typical of the family members Hadrosauridæ. The first types of these gigantic iguanodons was H. foulki, from Haddonfield in New Jersey.
- some of numerous huge bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; was partly aquatic