 The discovery of Iguanodon has long been accompanied by a popular legend . The story goes that Gideon Mantell 's wife , Mary Ann , discovered the first teeth of an Iguanodon in the strata of <unk> Forest in <unk> Green , <unk> , 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 agrees that the story is false , though . It is known from his <unk> that Mantell first acquired large fossil bones from the quarry at <unk> Green in 1820 . Because also theropod teeth were found , thus belonging to <unk> , 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 <unk> of the South Downs he as yet did not <unk> to suggest a connection between the teeth and his very incomplete skeleton , <unk> that his finds presented two large forms , one carnivorous ( " an animal of the <unk> 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 <unk> of a rhinoceros from a Tertiary <unk> . On 23 June 1823 Charles <unk> showed some to Georges Cuvier , during a <unk> in Paris , but the famous French naturalist at once dismissed them as those of a rhinoceros . Though the very next day Cuvier <unk> , <unk> reported only the dismissal to Mantell , who became rather <unk> 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 were of some giant <unk> — though still denying it was a herbivore . <unk> nevertheless , Mantell again sent some teeth to Cuvier , who answered on 22 June 1824 that he had determined that they were <unk> and quite possibly belonged to a giant herbivore . In a new edition that year of his <unk> sur les <unk> <unk> Cuvier admitted his earlier mistake , leading to an immediate acceptance of Mantell , and his new <unk> , in scientific circles . Mantell tried to <unk> 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 <unk> recognised that they resembled those of an iguana he had recently prepared , albeit twenty times longer . 
