Ouranosaurus - Classification

Classification

Taquet originally assigned Ouranosaurus to the Iguanodontidae, within the larger Iguanodontia. However, although it shares some similarities with Iguanodon (such as a thumb spike), Ouranosaurus is no longer placed in the iguanodontid family, a grouping that is now considered paraphyletic, a series of subsequent offshoots from the main stem-line of iguandontian evolution. It is instead placed in the clade Hadrosauroidea, which contains the Hadrosauridae (also known as "duck-billed dinosaurs") and their closest relatives. Ouranosaurus appears to represent an early specialised branch in this group, showing in some traits independent convergence with the hadrosaurids. It is thus a basal hadrosauroid.