An Iguanodon tooth, discovered and described by the Mantells in the early 1800s Our perception of Iguanodon has been changing for almost 200 years since the discovery of sparkling rocks by the side of the road this prehistoric reptile remains shrouded in mystery Discovered in Sussex in 1822, a collection of teeth was the first evidence of a gigantic herbivorous reptile named Iguanodon. This dinosaur and its closest relatives lived during the Early Cretaceous The crucial discovery helped to kick-start our fascination with dinosaurs Mary Ann Mantell (1795-1869) and her husband Dr Gideon Algernon Mantell (1790-1852) are recorded as having found the first evidence of Iguanodon Most accounts hold that Mary was accompanying her husband on a trip to visit a patient in Sussex when she noticed something glinting by the side of the road When Mary went to investigate she discovered a collection of fairly large teeth embedded in the rocks To try and determine what they belonged to who is sometimes referred to as the father of palaeontology Two of the Iguanodon teeth found by Mary Ann Mantell, still embedded in rock. See the teeth on display in Treasures in the Cadogan gallery Cuvier initially thought that the teeth could be from a fish comparable to pufferfish (Tetraodon) or porcupinefish (Diodon) he noted that the fossils' internal structure was different and that they may instead be from a new animal - possibly an herbivorous reptile Until that time, no evidence of giant prehistoric reptilian herbivores had been discovered. Remains of the large carnivore Megalosaurus had been in the collections of the Oxford University Museum of Natural History since the late 1600s but they were only described by William Buckland in 1824 - two years after the discovery of these Iguanodon teeth Gideon visited the Hunterian Museum (at the Royal College of Surgeons in London) to search for jaws and teeth of living reptiles with curator William Clift They had little success until they were shown an iguana skeleton that had been recently prepared by assistant curator Samuel Stutchbury Gideon Mantell noticed some similarities between living iguanas and his discovery Iguanodon. The rhinoceros iguana may also have been the inspiration for Iguanodon's thumb spike originally being depicted on its nose. © H. Zell via Wikimedia Commons (CC BY-SA 3.0) The fossilised teeth resembled those of the iguana but scaled up the prehistoric owner of the fossilised teeth could have been up to 18 metres or longer We now know this dinosaur reached a length of about 10 metres Gideon based the name Iguanodon on this link to iguanas (the name means iguana tooth) For several years Gideon searched for more evidence of Iguanodon they were usually isolated bones and teeth But his streak of smaller discoveries would come to an end when in 1834 some workmen accidentally blew up a slab of rock in a limestone quarry near Maidstone in Kent was discovered after being blown apart by explosives in a limestone quarry noticed a 'remarkable substance' resembling petrified wood in a large fragment of rock He then searched for and reassembled the many pieces blown apart by gunpowder With a hammer and chisel Bensted followed the outline of the bones until he had 'brought into view portions of the skeleton of an extraordinary animal which had been buried in the bowels of the earth probably in the earliest ages of existence' Among the bones embedded in the rock were rib fragments part of a tooth and a clear impression of another From the Maidstone Slab and living lizard skeletons Gideon Mantell conceptualised how Iguanodon might have been structured who then travelled to Maidstone to investigate and attributed the bones to Iguanodon With the Iguanodon fossils Mantell had available to him This concept may have been based on the living iguana species Cyclura cornuta - the rhinoceros iguana - which features a small horn near its snout Two Iguanodons (L) and Hylaeosaurus (R) drawn by Benjamin Waterhouse Hawkins Sir Richard Owen used Iguanodon (along with Megalosaurus and Hylaeosaurus) to coin the word 'dinosaur' in 1842 Iguanodon's horn was still a prevailing theory when Owen consulted on the construction of the Crystal Palace dinosaur sculptures in the 1850s Prior to the completion of the Crystal Palace dinosaurs in 1853 several notable scientists were invited to a dinner inside the Iguanodon sculpture. It wasn't until a significant Iguanodon discovery was made in the 1870s that it was proved that the spikes were thumbs rather than horns But there is still speculation about what they were used for Iguanodon's thumbs may have been used as defensive weapons either against its meat-eating predators or others of its species But other scientists believe that the spiked thumbs were specialised tools used for stripping foliage from branches or breaking into seeds The Crystal Palace Iguanodon sculpture was based on the belief that these dinosaurs had a spike on their nose rather than two thumb spikes as they would have had in life Although scientists can interpret from fossils that the dinosaur's spikes were large the bones are not representative of their full size in life The spikes would have been covered in keratin whereas dinosaur fossils only show the bony core It had thumb spikes for food preparation or defence three middle fingers fused into a 'hoof' for walking on and a fifth finger that was possibly used for grasping By this point no complete Iguanodon skeleton had been found - until a chance discovery in a Belgian coal mine in March 1878 Miners digging at 322 metres below the surface near the town of Bernissart began to dig through a pocket of clay when they discovered numerous bones encrusted with pyrite (also known as fool's gold) Informed by telegram, the head fossil preparator at the Musée Royal d'Histoire Naturelle de Belgique (now the Royal Belgian Institute of Natural Sciences) Over the following three years around 30 Iguanodon skeletons were uncovered One of the Bernissart Iguanodons is being assembled in Brussels in 1882. This chapel was the only location with a high enough ceiling for the job. Image via Wikimedia Commons. Covered in plaster for protection and broken into 600 blocks, the fossils were transported to Brussels to be reassembled and fitted with iron frames. For the first time, scientists were able to see what a complete dinosaur might have looked like. The giant dinosaur puzzles were assembled based on knowledge of the time, that Iguanodon was bipedal. We now know the dinosaur predominantly walked on all fours. The Belgian Iguanodons are now too fragile to be repositioned into life-like postures, however, so they remain a vestige of nineteenth-century thinking. The Bernissart mineshafts have long since been filled and sealed, making it impossible to search for other Iguanodons that may be buried there. But samples taken from the mines in the early 2000s contained bone fragments, suggesting that there may still be dinosaurs far below the surface. Discover how Iguanodon's true identity was finally revealed The Cretaceous Period is famous for ending with a massive asteroid impact but what was our planet like in the millions of years before that endless patience and skill to transform a fossil into a museum-worthy exhibit. Receive email updates about our news, science, exhibitions, events, products, services and fundraising activities. We may occasionally include third-party content from our corporate partners and other museums. We will not share your personal details with these third parties. You must be over the age of 13. Privacy notice Map Map We use cookies to give you the best online experience We use them to improve our website and content and to tailor our digital advertising on third-party platforms You can change your preferences at any time (Credit: Biodiversity Heritage Library/Illustrated History of the Natural Kingdom/S.G New York/1859)NewsletterSign up for our email newsletter for the latest science newsSign Up Few dinosaurs have had as many extreme makeovers as Iguanodon the herbivore has been imagined as a spike-nosed lummox In addition to reconstructing Iguanodon as a stout early paleontologists placed a finger bone on the animal’s snout Dining or dino-ing? A London event held inside a reconstructed Iguanodon was the talk of the town and helped cement the notion of the dinosaur as a tank-like It was one step forward, one step back when several Iguanodon specimens turned up in Bernissart, Belgium. The completeness of multiple individuals confirmed once and for all that the ol’ snout spike was actually a modified thumb Paleontologists also realized the animals were not dedicated quadrupeds and reconstructed it in a bipedal kangaroo posture — even though they had to misalign some of the bones to make it work The discovery of stiffened tendons along the tail established Iguanodon as no tail-dragger Other research during this dinosaur renaissance looking at the inflexibility of its hand and wrist revealed that Iguanodon spent most of its time with four limbs on the ground Will future Iguanodon reconstructions sport feathers? Stay tuned. Despite having a beak and being an ornithischian, or “bird-hipped” dinosaur, the animal isn’t closely related to the lineage that evolved into birds. However, since 2002 paleontologists have unearthed a couple of other ornithischians with primitive bristle or furlike feathers Read More: A Complete Dinosaur Timeline to Extinction: How Long Did They Roam Earth? Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles and our editors review for scientific accuracy and editorial standards Review the sources used below for this article: Extinct Animals. Iguanodon The History Press. The Victorian dinner inside a dinosaur Utah Geological Survey. The Thumb-Spiked Iguanodontians – Dinosaurian Cows of the Early Cretaceous Institut royal des Sciences naturelles de Belgique. On the Ornithischian Dinosaur Iguanodon Bernissartensis From the Lower Cretaceous of Bernissart (Belgium) Register or Log In Want more?Keep reading for as low as $1.99 Subscribe Save up to 40% off the cover price when you subscribe to Discover magazine The Cambridge Animal Alphabet series celebrates Cambridge's connections with animals through literature I is for Iguanodon – a thousand ages underground Visitors described the Crystal Palace's array of artwork fountains and glasshouse as like a trip to fairyland and the concrete monsters were the star of the show Scroll to the end of the article to listen to the podcast On New Year’s Eve 1853, a group of entrepreneurs dined inside the mould for a giant model Iguanodon and, it is reported, sang a rousing song in praise of dinosaurs. The chorus runs: The jolly old beast/Is not deceased/There’s life in him again! ROAR. The model that provided an unlikely dinner venue that December evening was part of a set of concrete dinosaurs – the world’s first full-size dino-sculptures – made for the Crystal Palace at Sydenham A plaster replica of a skeleton found in a mine in 1878 Iggy was given to the Sedgwick Museum by the King of Belgium The original creature would have measured 11 metres from nose to tail and weighed more than an elephant Fossilised bones of Iguanodon or its close relatives which lived between 140 and 120 million years ago in the Cretaceous Period have also been found in several places in Britain Iggy is posed in the ‘kangaroo-style’ posture that was an early interpretation of the creature's stance who was director of the Sedgwick Museum from 1991 to 2011 has shown in the course of his work on dinosaurs that this upright posture would not have been possible for an animal like this; it would have spent much of its time browsing and walking on all four legs Research by Norman has shown that three of the fingers of Iguanodon’s ‘hands’ were modified to form a load-bearing foot with toes that ended in broad The ‘thumb’ was a ferocious dagger-like spike while its ‘little finger’ was elongate and prehensile and could have been used to help grasp clumps of vegetation “The animal's back and tail were stiffened by bundles of bony rods – ossified tendons – that you can see if you look along the spine of the animal These bony tendons would have stiffened the back while it was held more or less horizontally and the tail would have acted as a heavy cantilever (or counterbalance) to the front part of the body,” says Norman “The bony tendons running along the sides of the spine would also have prevented the dinosaur from bending the base of its tail as seen in the skeleton in the Sedgwick Museum and adopting such a steeply upright posture." Underneath the skeleton is a fossilised footprint thought to have been made by an Iguanodon walking on a soft surface having eroded out of the cliffs near Atherfield Point on the Isle of Wight Collections manager Dan Pemberton says: “The footprint in the museum is approximately 17 inches long from the back of the print to the tip of the middle toe Even bigger footprints can be found in the Cretaceous rocks exposed on the foreshore of the Isle of Wight.” Iguanodon was one of the first dinosaurs to be discovered and scientifically described by the Sussex-based doctor Gideon Mantell (1790-1852) Mantell at first envisaged Iguanodon as a gigantic lizard-like reptile but later on he thought that it might have resembled something like a giant ground sloth One of his contemporaries (Richard Owen) – who invented the word dinosaur to recognise the existence of a group of stupendously large extinct reptiles – deduced that it must have been a sort of gigantic reptilian rhinoceros complete with a horn (a misplaced thumb spike) on the tip of its nose “The discoveries at Bernissart in Belgium helped greatly to clarify our understanding of this animal since the skeletons were mostly complete and articulated – their bones were preserved in more or less the same arrangement as they had been in life,” says Norman the animal's typical life posture was misinterpreted because the scientist was convinced that their habits were like those of giraffes rather than like rhinoceroses that browse low to the ground.” Norman has revealed many new and unexpected aspects of the way of life and general biology of Iguanodon He has also shown that there was a variety of Iguanodon-like dinosaurs that lived in southern England during the Cretaceous Period including Iguanodon itself and all of them had that very distinctive spiky thumb Dr Melanie Keene (Homerton College) explores the hugely enthusiastic public response to the creation of one of the world’s first sets of full-sized dinosaur models – including an Iguanodon based on Owen’s version of how it might have looked She says: “The models were made by sculptor Benjamin Waterhouse Hawkins for the landscaped gardens around the Crystal Palace in 1854 commercial version of the Great Exhibition that had been held in Hyde Park three years earlier the Sydenham enterprise was one vast project of visual education and the concrete monsters were the star of the show.” the sculpted beasts made it into the newspapers with coverage of a celebratory meal held in the mould of the Iguanodon model on New Year’s Eve 1853 and had even joined together in song to hymn their achievement: ‘A thousand ages underground,/His skeleton had lain,/But now his body’s big and round/And there’s life in him again!.. The jolly old beast/Is not deceased/There’s life in him again!/ROAR’ The Iguanodon model has come to be an iconic part of the South East London landscape versions of the Crystal Palace monsters have appeared in many children’s books over the past 150 years from E Nesbit’s Enchanted Castle to Topsy and Tim Meet the Monsters modifying the display’s original didactic intentions and instead converting models such as the Iguanodon into terrifying creatures that came to life at night and menaced the young,” says Keene in line with the increasingly outdated appearance of the creatures featured the monsters as rather funny-looking friends to children In 1970 Ann Coates combined both of these elements in her Dinosaurs Don’t Die (1970) which brought the Iguanodon model back to life as a character boy and creature cross London together to see a more modern interpretation of the Iguanodon on show at the Natural History Museum the contrast between the old and new forms brilliantly captured in John Vernon Lord’s evocative illustrations Keene adds: “Surviving the catastrophic fire that destroyed the main building in 1936 these amazing artefacts can still be seen today in Crystal Palace Park and have most recently been cast as objects in need of conservation a miniature version of Owen’s rhinoceros-like Iguanodon can be seen beside the full-sized skeleton in the Sedgwick Museum.” Next in the Cambridge Animal Alphabet: J is for a creature so clever it has been nicknamed the "feathered ape" by researchers Inset images: Louis Dollo supervising the reconstruction of an Iguanodon (Sedgwick Museum of Earth Sciences); Iggy's skull repaired and repainted in 2004 (Sedgwick Museum of Earth Sciences); Crystal Palace Iguanodon (Wikimedia Commons); Woodcut of the famous banquet in Benjamin Waterhouse Hawkins' standing Crystal Palace Iguanodon Woodcut of the famous (crowded) banquet in Benjamin Waterhouse Hawkins' standing Crystal Palace Iguanodon Credit: Wikimedia Commons I wish to receive a weekly Cambridge research news summary by email The University of Cambridge will use your email address to send you our weekly research news email. We are committed to protecting your personal information and being transparent about what information we hold. Please read our email privacy notice for details If you have any questions or need help you can email us Richard Luck RICHARD LUCK looks back on a little-known chapter from history when a chance discovery in a Belgian backwater produced one of science’s greatest ever finds ‘I think I’ve struck gold!’ So bellowed miner Jules Creteur upon discovering something sparkling 322 metres below the surface on a Belgian coal field which looks pretty but is far from priceless the ‘fool’s gold’ formed part of a fossilised tree stump Creteur removed the ancient relic and resumed digging was among the most important discoveries of any age By the time the palaeontologists were done with the site 30 near-complete dinosaur skeletons had been excavated And what this epic find from 1878 revealed would hugely advance our understanding of the beasts that dominated this planet for 165 million years Long though they might have ruled the world dinosaurs have only been known to science for two centuries remains of ‘terrible lizards’ were written off as belonging to extinct races of dragons (especially true of China) giants (pretty much anyplace the Bible held sway) or animal species that had been wiped out by the Biblical flood (see giants) Though the term dinosaur (Greek for ‘terrible lizard’) was coined by the biologist and palaeontologist Sir Richard Owen in 1842 the first remains were unearthed some 20 years earlier It is these identifications – by Gideon Mantell and William Buckland – that the Royal Mint has this year chosen to celebrate with a trio of commemorative 50 pence pieces Of the three species depicted – Megalosaurus Hylaosaurus and Iguandon – it’s the last of these that’s of particular interest Iguanodon came to mankind’s attention when Mary Ann Mantell chanced upon some fossilised teeth while her husband Recognising that the remains belonged to a long extinct creature Gideon Mantell’s determination to correctly identify the teeth led to Iguanodon becoming the first celebrity of the dinosaur world after further Iguanodon remains were unearthed near Maidstone interest in dinosaurs swelled to such an extent that when the Crystal Palace was relocated from Hyde Park to South London in the 1850s the sculptor Benjamin Waterhouse Hawkins was commissioned to create 33 prehistoric animal statues to take up place in the parkland beneath the great glass structure pride of place went to a pair of Iguanodons which Waterhouse Hawkins constructed under the watchful eye of Sir Richard Owen Owen was convinced that the species of old resembled modern-day animals ‘his’ Iguanodons looked rather like Haitian Rhinoceros Iguanas Quite how wrong Sir Richard had got things only became apparent some 30 years later when a band of Belgian miners made the discovery of a lifetime Mention dinosaur discoveries and the Gobi Desert and the Montana Badlands are more likely to come to mind than the Low Countries a town in the Walloon-speaking region of Belgium that Jean Creteur and his colleagues struck it lucky Not that they were quick to recognise the importance of their haul the miners drilled through an entire Iguanodon skeleton before noticing that they were no longer dealing with coal As Creteur said at the time: ‘What we had in front of us was something too black to be stone and yet too hard to be wood The pieces that we pulled out looked like broken ends of pit props.’ It was only after the material had reached the surface that Creteur and his crew realised that they were dealing with the fossilised remains of a vast prehistoric beast the mine’s directors sought to bring Belgium’s finest palaeontologist minds to Bernissart a feat complicated by the discovery having been made at the beginning of April it wasn’t long before a potential practical joke was recognised as the scientific find of the century So began a three-year project to remove fossil material from the Bernissart mine the head preparer of the Musée royal d’histoire naturelle de Belgique was charged with extracting the bones from the pit a feat he accomplished by exposing each skeleton in turn recording its location within the shaft and then applying plaster to the fossil to preserve it while it was taken from the mine in metre-squared blocks 14 complete Iguanodon skeletons had been retrieved from Bernissart turtles and a variety of fish and plant species De Pauw’s place in palaeontology’s pantheon would be assured some 30 Iguanodon had been brought to the surface Were it not for dwindling funds and the mine manager’s desire to resume normal service this era of discovery might have lasted decades a French-born assistant naturalist at the Royal Belgian Institute of Natural Sciences Dollo sort to mount the dinosaurs in lifelike poses So complete were the specimens De Pauw excavated it was now clear to everyone that the Iguanodon of the Cretaceous Period didn’t look an awful lot like the Crystal Palace behemoths the spike that British scientists had placed on the beasts’ snouts had now been more properly identified as a thumb – Iguanodon presumably used it in close combat with predators given how short Iguanodons’ forelimbs were – at least in comparison to its back legs – the dinosaur probably adopted a bipedal stance not unlike that of a kangaroo It was a notion reinforced by discoveries in America where scientists were convinced that species such as Hadrosaurus – another herbivorous animal not entirely dissimilar to Iguanodon – walked on two legs rather than four a bipedal Iguanodon that greeted visitors to Brussels’ Nassau Palace in 1883 the skeleton would acquire new company with each passing year a herd of 11 Iguanodon took pride of place in what is now the Royal Belgian Institute of Natural Sciences And besides these mounted specimens lay the remains of a further 19 animals still encased in the rock and in the positions in which they had been discovered The guest of honour at the exhibit’s unveiling was none other than Leopold II ‘I shall tell you what I think,’ the monarch murmured to Louis Dollo I think that the Iguanodons were some sort of giraffe.’ Ever the gentlemen Louis Dollo wholeheartedly agreed with the king Though they’d been dead for the better part of 65 million years the Iguanodons weren’t allowed to rest on their fossilised laurels Germany – having occupied Wallonia – dispatched eminent scientist Otto Jaeckel to Bernissart to see what else he could find the occupation didn’t last long enough for the invaders to pack up the Bernissart herd and send it back to Berlin as a gift for the kaiser Jaeckel and his fellow Germans were sent packing and Dollo and De Pauw got back to being the Ross Gellers of their day the pair were denied their dream of returning to Bernissart when first funding issues and then flooding meant that whatever still lay in the shaft would forever be beyond mankind’s reach There were still fresh chapters to be written about what the pair had found there further examination of the skeletons revealed that two distinct species of Iguanodon had been unearthed – Iguanodon bernissartensis the casts of which were dispatched to museums the world over named in honour of the man who identified those fossil teeth all those years ago in Lewes There was also the question of how so many specimens came to be found in the same place Since the Bernissart haul included bones from the predatory Megalosaurus some theorised that the Iguanodon had been chased over a cliff to their deaths But what with the abundance of aquatic fossils found alongside the dinosaurs in all probability the skeletons were found together as they had been washed down a river the clay at the bottom of which was particularly receptive to the process of fossilisation the Brussels skeletons contributed to a sizeable volte face of the kind that occasionally occurs in scientific fields the British palaeontologist David Norman was struck by the amount of soft tissue that coated the skeletons The vast number of tendons surrounding the spine and tail were of particular interest since they indicated that rather than the kangaroo-like pose Dollo advocated Iguanodon probably held its tail horizontally Add this to the hoof-like toes on the creatures’ forelimbs and Norman could but conclude that Iguanodon spent a good portion of its life on four legs just as his countrymen posited a century earlier since it has so many Iguanodon skeletons at its disposal the Institut royal des Sciences naturelles de Belgique has been able to remount specimens in accordance with Norman’s discoveries while retaining some – admittedly very impressive – three-metre high bipedal exhibits Providing the focal point of the biggest single-room dinosaur exhibit on the planet the Bernissart Iguanodon herd ought to considered one of Europe’s most celebrated museum collections That it isn’t is almost as sad as the fact that the Crystal Palace Iguanodons have been placed on a Historic England ‘at risk’ register this in spite of them enjoying Grade II Listed status What with the fragile nature of the Brussels skeletons – they have to be exhibited as a specific temperature to guard against decomposition – Europe could lose two ground-breaking dinosaur landmarks in very short order Dinosaurs ruled our world for more than 150 million years How tragic it would be if their remains and their memory proved unable to last out the 21st century For more on the Crystal Palace dinosaurs and their preservation visit cpdinosaurs.org