English: Bolong is an iguanodontian dinosaur that lived about 125 million years ago in the Early Cretaceous of what is now China, and the most basal known hadrosauroid from Asia. It was a fairly small herbivore, growing to about 4 m in length, and around 200 kg in body mass. Thanks to the proportions of the limbs, there is some debate whether Bolong walked on two legs or four, but it is generally thought to have been facultatively bipedal like most related dinosaurs. This means it could choose between both forms of locomotion.