The discovery of Iguanodon have long been accompanied by a popular legend . The story go that Gideon Mantell 's wife , Mary Ann , discovered the first teeth of an Iguanodon in the strata of Tilgate Forest in Whitemans Green , Cuckfield , Sussex , England , in 1822 while her husband was visiting a patient . However , there is no evidence that Mantell took his wife with him while seeing patients . Furthermore , he admitted in 1851 that he himself had found the teeth . Not everyone agree that the story is false , though . It is known from his notebooks that Mantell first acquired large fossil bones from the quarry at Whitemans Green in 1820 . Because also theropod teeth was found , thus belonging to carnivores , he at first interpreted these bones , which he tried to combine into a partial skeleton , as those of a giant crocodile . In 1821 Mantell mentioned the find of herbivorous teeth and began to consider the possibility that a large herbivorous reptile was present in the strata . However , in his 1822 publication Fossils of the South Downs he as yet did not dare to suggest a connection between the teeth and his very incomplete skeleton , presuming that his finds presented two large forms , one carnivorous ( " an animal of the Lizard Tribe of enormous magnitude " ) , the other herbivorous . In May 1822 he first presented the herbivorous teeth to the Royal Society of London but the members , among them William Buckland , dismissed them as fish teeth or the incisors of a rhinoceros from a Tertiary stratum . On 23 June 1823 Charles Lyell showed some to Georges Cuvier , during a soiree in Paris , but the famous French naturalist at once dismissed them as those of a rhinoceros . Though the very next day Cuvier retracted , Lyell reported only the dismissal to Mantell , who became rather diffident about the issue . In 1824 Buckland described Megalosaurus and was on that occasion invited to visit Mantell 's collection . Seeing the bones on 6 March he agreed that these was of some giant saurian — though still denying it was a herbivore . Emboldened nevertheless , Mantell again sent some teeth to Cuvier , who answered on 22 June 1824 that he had determined that they was reptilian and quite possibly belonged to a giant herbivore . In a new edition that year of his Recherches sur les Ossemens Fossiles Cuvier admitted his earlier mistake , leading to an immediate acceptance of Mantell , and his new saurian , in scientific circles . Mantell tried to corroborate his theory further by finding a modern @-@ day parallel among extant reptiles . In September 1824 he visited the Royal College of Surgeons but at first failed to find comparable teeth . However , assistant @-@ curator Samuel Stutchbury recognised that they resembled those of an iguana he had recently prepared , albeit twenty times longer .