I is for Iguanodon

Author’s Note: I just realized that I have an excellent book that covers the story of Gideon Mantell and the iguanodons. This book, Terrible Lizard by Deborah Cadbury, contains all sorts of juicy details about the scientific rivalries, the tooth, and the horn. Unfortunately, I haven’t read it entirely yet, so this post will be based on bits and pieces of what I have cobbled. They’re still tasty bits. Dinosaur Cobbler.

Model of the originally envisioned Iguanodon, in a Dinosaur Museum in Colorado. Photo by kajmeister.

Gideon Mantell was thrilled to find the palm-sized rock that seemed unnaturally pointed and curved. He knew it came from an animal–probably an ancient animal. It seemed logical that it might be similar to a horn, like the one on a rhinoceros.

Oh, what a howling error! Mantell would be known forevermore for his mistake. Was it his fault, given that the foremost naturalist of his day insisted the animal was a rhinoceros? He also was pooh-poohed by the other scientists, only to have them become famous for his initial ideas. Maybe history should be kinder to Gideon. Still, he also dissed his wife. It was Mary who found the fossils, let him fill their dining room with samples, organized his papers, drew illustrations for his book, raised his children … and then was forced to move out when the house was turned into a museum. On second thought, let’s not cut him any slack.

Who Found the Tooth?

Iguanodon was only the second dinosaur to be discovered and named formally by the scientific community that runs such things, which in the early 19th century was in England. The idea of dinosaurs, the extent of dinosaurs rule over the planet, and their huge variation in function and design was all yet to be discovered in 1820. When the quarry near Gideon’s medical practice started revealing unusual fossil bones, there was some ambiguity about what animal it might have come from.

Gideon and Mary Mantell, drawings from UK Natural History Museum blog.

There’s also some confusion about who might be credited with the first discovery of the tooth. According to author Deborah Cadbury, it was Mary, though Wikipedia and other sources suggests there is debate. Mary apparently did accompany her husband to his practice, according to Cadbury, and both of them liked finding interesting specimens. She found the tooth. Gideon told people that she did so, and it’s in the diaries. Later on, when they became estranged, he changed his story; after the tooth became famous, he changed his story.

Tooth discovered by Gideon, illustrated by Mary. Photo from UK Natural History museum.

Gideon had already found a few large bones in Whiteman’s Quarry, near his practice, when Mary brought him the tooth. The other bones were scattered, fragmentary, and their eroded state made it unclear of their source–a giant fish? Mastodon? There was too little information. Yet the tooth was different. Its shape and design was similar to an iguana’s tooth, though of course, it was much bigger. An animal with such a tooth might be 10 to 15 meters long. Mary had discovered the tooth on a walk, but they were able to trace its source back to more rocks from Whiteman’s Quarry. Gideon started spending a lot of time at the quarry, and gradually uncovered dozens of bones and fossils, various specimens.

Mary, as it turned out, was an excellent illustrator. She made drawings of the finds–mostly Gideon’s finds–but her illustrations helped fill out the book he was writing. She also was raising two of his children and keeping the large house organized, even as Gideon started placing his finds in the parlor and dining room.

Other fossil illustrations from Mary, from wikimedia.

Only a Rhino, Scoffs the Frenchman

Gideon began circulating his finds among the naturalist minds of his era. Initially, his arguments were rebuffed. Georges Cuvier, a vaunted French scientist who had written the definitive work on the Ice Age mammals, told him the tooth looked like that of a rhinoceros. William Buckland, a creationist who wanted ancient animals to fit in with a biblical timeline, told Gideon that he was mistaken about the geology of the quarry. Buckland insisted that Mantell had found the bones in a different strata of geology than he believed.

Mantell was told he was wrong six ways from Sunday, but he persisted. He spent more time at the quarry, dug up more fossils, continued to turn his house in a museum, and talked to anyone who would listen for five minutes. Buckland still ignored him, although Georges Cuvier came around and admitted his error. Mantell’s ideas began to attract attention, including the notice of a young assistant to a natural history museum, Richard Owen. They spent a lot of time together; Owen had connections.

Eventually, the Mantell Museum (formerly his house) became so elaborate that Mary and the family had to move out. At first, she continued to come back to help and visit. Over time, her estrangement became permanent. The museum attracted plenty of visitors but very little money. Despite trying to get royal patronage (and money), Mantell was ultimately unable to afford maintaining the museum. He had to sell most of his collection, though he had at last achieved the notoriety he sought. He was at last considered the Iguanodon expert.

Horn or Spike?

Two additions to the Iguanodon/Mantell story are notable. One concerned the placement of the pointed fossil, slightly larger than Gideon’s hand. Cuvier had told Mantell that his discovery was probably just a rhino; so had Buckland. We know now that plenty of dinosaurs had horns. It was not a terrible error for Gideon to place the bone on the forehead of his iguanodon.

Iguanodon fossil discovered by Mantell, photo from fineartlibrary.

But it turns out that iguanodons were fairly prevalent in the region, even more so on the northwestern part of Europe. Eventually, other iguanodon skeletons were discovered in Belgium and France, and the pointed spike was found to be part of the front claws. With lots more bones and lots more ancient reptiles identified, Iguanodon was eventually set up on hind legs, more like a kangaroo.

Comparative Iguanodon thumb claw and other claws. Photo from UK Natural History museum.

With this upright design, then the pointy object could be portrayed as a claw rather than attached to the forehead. Particularly once other horned fossils were discovered, with the horns were still attached to the head crest, it was hard to see Gideon’s pointy fossil as a part of the head. The horn became a thumb spike. The error was firmly attached to Gideon Mantell’s reputation.

Iguanodon belgique, the official Iguanodon. Photo from Pinterest

Dinner in a Dinosaur

The other postscript to Mantell’s discoveries involved Richard Owen, a man who turned out to have some nerve. Owen had aristocratic patrons and more than a little showmanship. Mantell was a painstaking scientist; Owen wanted to grandstand. They argued over the design and structure of the reptile discoveries. He also ridiculed Mantell’s size estimates, claiming that no such reptiles could be that big. Owen was the one who coined the phrase “dinosaur,” and, given the chance, Owen took the lead in publicizing the dinosauria that Mantell and a few others had originally struggled to explain.

The two naturalists were asked to help build out exhibits for London’s 1850 Great Exhibition, which included the Crystal Palace. Mantell designed a series of sculptures, but died before they were put before the public, so he did not have a chance to oversee the work. Owen saw to their completion, his vision of these ancient animals as clumsy, lumbering creatures like elephants, was the one that lasted. It was Owen’s portrayal of the iguanodon that the world saw, despite Mantell’s work in making the discoveries in the first place.

Perhaps the worst example of grandstanding came as the large structures were being assembled for display. Owen invited a group of wealthy donors to dinner. The newspaper report and depiction was both fascinating and bizarre. The idea of dinosaurs began to grow in popular appeal.

The ignominy for Gideon Mantell was not yet over.

While his discovery of teeth and spikes had prompted the discussion of the iguanodon, and originally had been honored with the name Iguanodon anglicus, his species was eventually eliminated. It was termed a nomen dubium, meaning that there wasn’t enough of a definitive skeleton found to deserve a separate species. Gideon’s bones were ultimately recategorized under the species of Iguanodon Bernissartensis, from the bones discovered in the quarries of Belgium.

The tooth was bequeathed to Gideon’s son, William, who had moved to as far away as possible. The iguana tooth that started it all — that created the species name of Iguana + Don–now belongs to the museum, Te Papa Tongarewa, in Wellington, New Zealand.

It’s not even on display.

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