The Fossils of the South Downs is a survey of the paleontological discoveries made by the geologist Gideon Mantell and his wife Mary Ann Woohouse at Tilgate Quarry near Cuckfield. The Mantells had discovered fossilised fish and bones that were larger than those uncovered by William Buckland in Oxfordshire. While preparing this book for publication in 1822, Mary Ann discovered fossilised teeth that did not match those of any of the specimens they had previously uncovered. Mantell noted that they were similar to those of an iguana and in 1825, he named the new creature Iguanodon. It was the second dinosaur to be named after Buckland’s naming of Megalosaurus the previous year.
By the time the book was published, Mantell had come to the attention of George IV, who headed the subscription list and requested four copies.