Iguanodon bernissartensis

Coloration:
Male – Forest green with a lighter green belly and darker striping or blotches on the back, tail, and legs. There is a white stripe on both sides of the body, reaching from the lower side of   the tail and across the thighs to the underbelly beneath the armpits. There is a white mark across the lower face and side of the neck. The throat region is a vibrant, blood-red, giving the impression that the throat has been slit. A reddish hue that extends down the chest furthers the illusion of blood running down its front. The red is most vibrant in dominant adults; the necks of subordinate and younger males are more a dull pink.

Female – Like the male, except with a yellowish-green on the throat instead of red.

Juvenile (both sexes)– Bright, forest green without markings of the adult, with yellow throat like the adult female. Males develop the pink throats as they reach maturity.

Diet:
A wide variety of vegetation which it chews with its grinding cheek teeth.

Preferred Habitat:
Forests or plains dotted with clusters of trees.

Social Structure:
Large herds with a single dominant male in charge of a few other males, many females and young. Females within the herd are subordinate to the males.

Description:
Large, heavy bodied quadrupedal herbivore. From a  distance, Iguanodon can be mistaken for a crest-less species of  hadrosaur. Long head with toothless beak, back teeth hidden by fleshy cheeks. Forelegs smaller than hind legs. Capable of traversing on its hind legs for short distances. Iguanodon’s hand is a specialized tool and is probably the most defining feature of this animal. The three middle fingers are stout and joined together, forming hooves used for walking. The fifth finger is opposable and can curl around objects to grasp; and the thumb is modified into a huge spike - the Iguanodon’s main weapon. The male is larger than the female, and its thumb spikes tend to be larger as well.

Behaviors:
Iguanodon is generally peaceful unless disturbed, and herds can often be seen feeding alongside the much smaller Dryosaurus as well as other herbivores. However Iguanodon - especially the males – are among the most aggressive and dangerous of ornithopods on Isla Sorna, nearly on par with Stegosaurus and Triceratops. Most predators are wise to avoid these fearsome herbivores, and those that do hunt them usually only target the more vulnerable individuals such as   the young or the sick. Healthy adults are very powerful and will defend themselves with their bulk and deadly thumb spikes. When under threat, the adult females form a defensive wall around the more vulnerable members of the herd while the males on the outside fend off their attackers with noise and much aggression. If a predator has been captured by one of these herbivores, it will be lucky to escape alive, as the Iguanodon will be sure to trample, pound, and stab the unfortunate carnivore repeatedly until there are no more signs of life.

In an Iguanodon herd, the dominant male can often be distinguished from the others by his large size and the vibrant red of his throat. Often he is also heavily-scarred, as he is the most active in the defense of his herd against predators and rival males. The breeding season is the time when the males of the herd challenge one another for ultimate dominance. During minor disputes, males show off their thumb spikes in wide stabbing motions, remaining at a distance to avoid serious injury. However, if the contests become more intense, the males will move on to tackling one another - trying to force their opponents to the ground. The winner will establish or retain his dominance over the herd and win mating rights. The dominant male has to defend his post from several young, strong candidates, and if he is able to hold them off long enough he will keep his position for another year. He mates with all the females; prevents the subordinate males from doing so; resolves disputes between male and female alike; and fights off various species of predator with the help of his subordinates. Even Dryosaurus, constant companions throughout the majority of the year, keep a wide berth during the breeding season for fear of being caught up in the male's violent disputes.

When a dominant male has finally emerged from all the fighting, he is  safe to court the females in peace. The surge of testosterone will ensure his throat becomes redder and more vibrant, and he will progressively bulk out with muscle over the next few days. The excessive quantities of male hormone also renders him highly aggressive, and like a male Triceratops, he will attempt to charge at even harmless animals that get too close to his herd. The females, however, tend to be impressed by such machoism, wanting a strong male to father strong offspring.

While Edmontosaurus, Corythosaurus and Parasaurolophus nest together in colonies, Iguanodon prefer to mingle with their own kind. Similarly to the hadrosaurs, female Iguanodon build nests that are close together with enough room for the adults to move between, and all help one another protect the eggs and hatchlings from predators. When it comes to feeding and raising the young, male Iguanodon are not so involved like Corythosaurus, Parasaurolophus and Edmontosaurus males, and instead remain on the perimeter of the nesting area, keeping on constant guard. Any small nest raider foolish enough to get too close are charged, often pummelled and stabbed to death if they are unlucky enough to be caught. For this reason, it is very difficult for an Iguanodon egg or nestling to be stolen.

Iguanodon calls include deep roaring and bellowing, as well as snorts and grunts. Male Iguanodon make a lot more noise than the females and young, particularly during disputes with other males; warning off predators; displaying to females; and keeping herd members in line. It is generally the dominant male which produces the loudest calls and makes the most noise.