In April 1878 some Belgian coalminers discovered a mass of giant bones 322 metres underground at Bernissart, Belgium. 31 skeletons were extracted by scientists from the Royal Museum of Natural History in Brussels, under the direction of Louis Dollo. It seemed that all 31 adults had died in a deep ravine, though not necessarily at the same time. Dollo was able to prove that the Iguanodon was two-legged, and that the spike which Mantell and Owen had placed on its nose was in fact a thumb.
Dollo spent nearly all his working life studying and reconstructing these skeletons, and his work took the study of dinosaurs to a new level. The skeletons were reconstructed in a church - the only building large enough - before being transferred to the museum, where they can still be seen today