The Iguanodon was a large herbivorous dinosaur that lived during the Upper Jurassic and Lower Cretaceous periods. It was first discovered in 1822 by Gideon Mantell in England. The name Iguanodon means “iguana tooth” and was given to this dinosaur because its teeth resembled those of an iguana.

Key Facts

Iguanodon pronunciationig-WHA-noh-don
What does Iguanodon mean?Iguana tooth
Dinosaur typeEuornithopod
On the menuHerbivorous
Length33 feet (10 meters)
Height14 feet (4 meters)
Weight9000 lbs (4000kg)
Life expectancyUnknown
Legs used to get aroundBipedal/quadruped
Estimated top speed15 mph (24 km/h)
When they livedLower Cretaceous era 140-110 million years ago
Where they have been found?Belgium and the United Kingdom

When & Where

The Iguanodon was one of the first-ever dinosaurs to be correctly identified and named in 1825, after the Megalosaurus. It was also one of the first dinosaurs to be depicted in popular culture, appearing in several books and films during the 19th and 20th centuries. Today, fossils of the Iguanodon have been found on every continent except Antarctica.

It was first discovered by William Harding in 1822 and named by Gideon Mantell in 1825. The striking similarity between the dinosaur’s teeth and that of an iguana helped Mantell to establish the fact that dinosaurs were reptiles.

Years later, in 1878, some miners found numerous large fossil bones while mining in Bernissart, Belgium. These were complete skeletons that helped to support and improve on Mantell’s earlier findings. Other Iguanodon fossils have since been found in England and North America.

Size & Weight

Iguanodons were large dinosaurs, measuring up to 10 meters (33 feet) in length and weighing up to 4 tonnes (8800 pounds). They could stand up to 4 meters (13 feet) tall at the hip.

The Iguanodon is classified under the family Iguanodontidae, which contains several other well-known dinosaurs such as the Dryosaurus and the Ouranosaurus. This dinosaur was a large, slow-moving creature that measured up to 30 feet in length and weighed around 2.5 to 3 tons. Its most distinctive features were its thumb spikes, used for defense against predators, and its five-fingered forelimbs, which were much more flexible than its contemporaries.

Mobility & Diet

The Iguanodon was a plant-eating (herbivorous) dinosaur. Its ridged teeth were specially adapted to grinding down plants. Iguanodons probably fed on ferns, palms, and horsetails that grew near streams and rivers. Their bones in the jaws and skull were not tightly fused, which allowed them to move these bones when chewing tough plant material.

This dinosaur was a slow-moving creature that moved on all fours most of the time. However, it could stand upright on its hind legs when necessary. Its long, flexible forelimbs allowed it to pick leaves high up on trees. They are estimated to have had a top speed of around 24 kilometers per hour (15 miles per hour).

Interesting Points

  • Iguanodons had five-fingered forelimbs, unlike most other dinosaurs, which had three-fingered forelimbs.
  • The thumb on an Iguanodon’s hand stuck out at a right angle from the rest of the fingers and ended in a sharp, cone-shaped spike. This thumb spike was probably used as a weapon against predators.
  • The Iguanodon was one of the three earliest dinosaurs to be discovered and formally named.
  • The Iguanodon is one of the most well-known dinosaurs, thanks to its many fossil remains.

Featured Image Credit: Nobu Tamura, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons