In 1897 French paleontologist Henri-Émile Sauvage referred a tail vertebra from the Kimmeridgian of Portugal, present in the collection of the Musée Géologique du Boulonnais at Boulogne-sur-Mer in France, to Iguanodon prestwichii, a herbivorous iguanodont.[1] The holotype, once having the inventory number MGB 500 but later lost, was a distal caudal vertebra, 152 millimetres long. The species was by von Huene considered a member of the Coeluridae but is now generally seen as a nomen dubium, Neotheropoda incertae sedis.