The Maidstone Iguanodon

Glimpse quickly at the Maidstone coat of arms and at first you may not notice the strange haughty-looking lizard wielding a shield with a lion. Guy Lochhead shares the curious history behind this strange beast, with a spike for a thumb, which was found embedded in Kentish rock in 1834.

Nineteenth-century painting showing&nbsp;  Iguanodon&nbsp;  in a tripod pose.

Nineteenth-century painting showing Iguanodon in a tripod pose.

In the early 1800s, there was a spate of paleontological discoveries that pushed our understanding of dinosaurs to new levels. Fossil collector Mary Anning’s 1811 discovery of a huge crocodile-like monster at Lyme Regis led many amateur geologists across Britain to fervently reassess their finds. While in 1824 clergyman and geologist William Buckland accidentally undermined his faith with the discovery of a “great lizard”– megalosaurus – in the Cotswolds. 

Further east, physician Gideon Mantell was examining giant leg bones he’d found in Tilgate Forest sandstone, wondering if they might also be from one of these new prehistoric beasts by examining the age of the stone they were embedded in. While Mantell worked as a doctor, his wife, Mary Ann Woodhouse, would also go fossil-hunting. One day, in 1822, she found some large teeth in that same layer of sandstone. Gideon noticed that they had a strange resemblance to those of the extant iguana, but 20 times larger. He called this giant “Iguanodon” – the second dinosaur to ever be named – and proposed a huge, herbivorous reptile. The announcement was met with derision, since plant-eating reptiles were so rare, and it took three years for his findings to be accepted.

In 1834, a more complete skeleton was discovered at Bensted’s Quarry in Maidstone, reaffirming Mantell’s ideas. The significance was enormous – for the first time, palaeontologists could begin to speculate as to the form of these monsters. Friends of the Mantells bought the rock from the quarry master for £25 and named it the “Maidstone Slab”. Gideon examined the bones embedded in the rock alongside the old teeth and drew a massive iguana, perched incongruously on a branch, quadrupedal, grinning madly, wielding a stubby horn at the end of its nose. This strange assemblage gave the first glimpse of what our planet’s previous tenants might have looked like.

After providing this insight, Mantell’s life became tragic. He moved to Brighton and his medical practice failed. The council intervened and turned his house into a museum, but Mantell’s generosity and enthusiasm for fossils meant he waived the entrance fee to the point where the project was unsustainable. Within five years, he’d sold his entire collection to the British Museum for £4,000, Mary left him, his son moved to Australia, his daughter died and he suffered a carriage crash that left him with a spinal injury and chronic pain. He became addicted to opium and overdosed in 1852, fell into a coma and died. He was credited with naming four of the five known genera of dinosaurs at the time of his death.

The Iguanodon features on the Maidstone Coat of Arms

The Iguanodon features on the Maidstone Coat of Arms

In the Maidstone coat of arms, his marvellous beast stands erect on its hind legs, with the fossils he’d drawn as a horn worn proudly as thumbs – quite different to that first rough sketch. As more finds emerged, we have been able to augment and clarify his work. We have learned that iguanodon is a genus, not a species; that they did walk mainly on all fours, though they may have stood to feed; that they were indeed herbivores; and that the “horn” was in fact a thumb spike, though we still don’t know its function.

Proudly anachronistic beside the petty symbols of patriotism and governance, the Iguanodon stands for something far greater. Through the medieval language of heraldry we can look back a 150 million years, past the Victorian scientists who gave us this perspective, to the Late Cretaceous period. It gives us a perspective beyond our pomp and ceremony and shows that we are just this land’s current tenants. This hasn’t always been Maidstone, and nor will it always be.

You can visit the Mantell Monument at Whiteman’s Green in West Sussex, and see the Maidstone Slab in the Dinosaur Gallery of the Natural History Museum

Words by contributing editor Guy Lochhead