English: Gonkoken is a hadrosauroid ornithopod dinosaur from the Late Cretaceous of what is now Chile. It was fairly small, at approximately 4 m in length, and shows a combination of basal and more derived hadrosauroid traits. Gonkoken's taxonomical and geographic placement prove that non-hadrosaur hadrosauroids survived in South America until the end of the Cretaceous. Based on this, it is hypothesized that the ancestors of Gonkoken migrated south to fill herbivorous niches before being outcompeted by more advanced hadrosaurs in the northern continents.