These are Iguanodon. These are very successful dinosaurs. More than 70 million years on the Earth, they colonize every single continent.
— Allen, describing Iguanodon

Iguanodon (name meaning "Iguana Tooth") is a genus of ornithopod dinosaur that originated during the Early Cretaceous period in various places around the world. Famous for being one of the very first dinosaurs ever discovered, Iguanodon was a species of dinosaur that walked on four legs and ran on two and a distant relative of the Hadrosaur family of dinosaurs. Measuring 9–11 meters long and weighing 3–4 tons, it was also said to have been the most successful dinosaur that ever lived.


Era & DiscoveryEdit

Iguanodon lived during the Early to Late Cretaceous period from 145–65 million years ago. They were very successful dinosaurs, in fact, among the most successful dinosaurs on Earth, that had existed for 80 million years throughout the Cretaceous, inhabiting all the worlds continents and prospering in various plants and vegetation. They were prey animals for carnivores like Sarcosuchus, Deinonychus, Utahraptor, and the immense Giganotosaurus. Iguanodon was named in 1825 by English geologist Gideon Mantell but discovered by William Harding Bensted.

Physical AttributesEdit

There were several species of Iguanodon all across the globe during the Cretaceous period and they varied in size and appearances, but nevertheless, Iguanodon were bulky herbivorous dinosaurs with chewing teeth, thumb spikes, and could shift from biped to quadruped.

They all weighed about 3–4 tons (6,000–8,000 lbs.), but the North American species, named Dakotadon lakotaensis, was the smallest and measured about 30 feet (9 m) long and stood 10 feet (3 m) tall at the hips. The larger European species, called Iguanodon bernissartensis, was 33 feet (10 m) long and 11 feet (3.4 m) tall at the hips. The largest was a South American species known as Macrogryphosaurus gondwanicus, measuring 36 feet (11 m) long and standing 12 feet (3.7 m) tall at the hips.

Contrary to what was previously thought, although these herbivorous dinosaurs walked in a quadrupedal stance, they were capable of running in a bipedal manner. And this makes them quit nimble, more so than slow-moving dinosaurs like the ankylosaurus, such as Polacanthus. It had long hind legs and shorter front legs. It had a long head with a blunt beak. Inside its mouth was a large battery of teeth designed to grind plant matter rather than to just rake the leaves off. On their front legs, the thumbs on their front legs were spikes and acted as a last line of defense against predatory dinosaurs. 

Behavior & TraitsEdit

Like many herbivores, Iguanodon were social animals that lived in vast herds, with as many as hundreds of thousands of individuals in a single herd, as a method of protection due to the fact that individually, they had barely any weapons or means of defense. The young often played around adults. As a herd, however, these dinosaurs could stampede, overrunning their predators and trampling them into the ground. However, living in these large herds, they would also have constantly migrated to find new growth to feed on.

Iguanodon were preyed upon by the large predator Giganotosaurus, the massive crocodile Sarcosuchus, and the giant dromaeosaur Utahraptor. However, whilst it was defenseless against Giganotosaurus and Sarcosuchus, Iguanodon's bulk and weight may have helped it shake off a single attacking Utahraptor. On the other hand, if there were multiple Utahraptors attacking it at the same time, it would stand little chance.

One particular reason Iguanodon were as successful as they were was because they developed a new way of dealing with plants in the Cretaceous. Whereas most dinosaurs, carnivore or herbivore, could only crudely slice food with their teeth, Iguanodon, however, was not only the first herbivores but the first dinosaurs to develop back teeth designed to grind up vegetation before swallowing. This ability to chew sped up the digestion of even the toughest planet material.

Journal EntryEdit

Iguanodon, "Iguana Tooth", is said to have been the most successful dinosaur that ever lived. Having existed during the entire time of the Cretaceous Era, Iguanodon lived on every single continent on Earth and thrived in a variety of vegetation. Over 35 feet in length at maximum and more than 3 tons in weight, these were big dinosaurs.

Iguanodon also lived in columns of huge herds, ranging to thousands of individuals in a single heard. While Iguanodon walked on all their four legs, they were able to run on two of them. They also possessed thumb claws that allowed them to defend themselves against predators like Utahraptor and Giganotosaurus.

Unlike other dinosaurs, Iguanodon was able to chew their food into pieces by moving their jaws from side to side, not unlike we humans do today. Their teeth were designed to grind vegetation before swallowing. Iguanodon was among the first creatures to have these kinds of teeth.

— Allen, in his Journal, about Iguanodon



  • The sound effects of Iguanodon are that of moose, altered elk, cow, donkey, and bison sounds.