Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade of the iguanodont group Ankylopollexia. In the past, Iguanodontidae became a repository for any ornithopod that did not belong in either Camptosauridae, Hadrosauridae or Hypsilophodontidae. However, a number of studies demonstrated that Iguanodontidae as traditionally defined is paraphyletic with respect to Hadrosauridae. Nevertheless, a handful of recent cladistic analyses have found support for a monophyletic Iguanodontidae consisting of a handful of taxa, including Barilium, Bolong, Iguanodon, Jinzhousaurus, Mantellisaurus, Ouranosaurus, and Proa.