Length: 28 feet
Height: 11 feet
Weight: 8 tons
- Adult and juvenile (both sexes): Brown underbellies and dark gray back plates. The facial area is a reddish-brown color.
Low-lying vegetation. Ankylosaurus does not chew its food - it is a fermenting herbivore, with a wide belly full of stewing meals which it has swallowed whole. Ferns, fruits, tubers, and even fungi are on the menu for these beasts. As a result Ankylosaurus is prone to frequent boats of flatulence
Ankylosaurus will live just about anywhere with sufficient vegetation, although its huge bulk prevents it from entering the denser forests and upland regions of Isla Sorna
Solitary, although tolerates others of its kind in close proximity.
Quadrupedal herbivore. Ankylosaurus is one of the most heavily-built animals on the island; the dinosaur equivalent of an armored tank. Its mighty back clad in scutes and spikes keep the animal safe even from the powerful jaws of giant predators such as Tyrannosaurus. Even its eyelids are armored. If all this protection wasn't enough, Ankylosaurus also wields a thick lump of solid bone the size of a beach ball at the end of its powerful tail, serving as a deadly weapon
All year breeder. Males and females mate when they happen upon one another and the female is in the right condition.
Despite its formidable arsenal of weapons and armor, Ankylosaurus is a somewhat peaceful animal and will even tolerate carnivores around it to a certain degree. If threatened however, it will produce a loud, rumbling bellow, swinging its tail in an attempt to deter the attacker. Ankylosaurus has perhaps the strongest hips of any dinosaur, and is therefore able to to swing its heavy club with enough force to shatter the femur or skull of large predators. A well-aimed blow could potentially disable the largest of carnivores, and even pulverize massive trees. However, Ankylosaurus is not entirely invincible - its soft underbelly is its most vulnerable spot. Flipping one of these heavy, well-armored herbivores is nigh impossible, but when dealing with a particularly persistent predator such as Tyrannosaurus, Ankylosaurus will dig its limbs into dirt or sand to protect its vulnerable underbelly and throat.
Ankylosaurus is not particularly territorial, however when there is a chance for mating males will challenge each other by slamming their powerful clubbed tails repeatedly into the ground while intermediately bellowing at their rivals. If neither male are intimidated by this show of noise and strength, they will stand side by side and proceed to shove and pound one another into submission. While their tough armor protects their bones and organs, these contests can leave males bruised and disoriented, and vulnerable to predator attack. As Ankylosaurus is quite a slow-moving creature, small birds have been known to take refuge upon its broad carapace, sometimes even making nests between the spikes. In particular, the primitive bird Archaeopteryx is sometimes known to use Ankylosaurus backs as their own private perches. The bird is protected from its predators and catches insects stirred up by the Ankylosaurus movements, while Ankylosaurus itself is barely aware of the presence of its riders except for when the shrill warning shrieks the Archaeopteryx emit alerts it to the presence of danger.
Ankylosaurus has poor eyesight, but it makes up for this with a heightened sense of smell. Owing to its poor eyesight, Ankylosaurus is easy to spook and therefore does not cope well with sudden movements. As a result it can be a danger to small, fast-moving herbivores such as Gallimimus and Dryosaurus, which - to the Ankylosaurus - vaguely resembles small two-legged predators. Slower moving herbivores such as hadrosaurs are less of a problem, and in fact are beneficial to the Ankylosaurus for their better eyesight and loud warning calls. While Ankylosaurus may mingle freely with other large herbivores, it typically does not need the protection of a herd, nor does it have the brain capacity for complex social interactions.
The female Ankylosaurus will lay her eggs in shallow scuffs of dirt in more forested regions, and she will refuse to leave while the eggs are incubating. Mothers are very protective of their young, and will defend them to the death. The young lack the hard carapaces of the adults and their tails lack the solid lump of bone, and thus they are much easier to kill if predators are able to separate them from their mothers. Unfortunately, this is not easy, as the scutelings walk directly under the female's tail. Ankylosaurus vocalizations include hippo-like grunts, deep, low tones, and deep bellows. The calls of the juveniles are somewhat higher in pitch, and their distress calls resemble a pig-like squealing. This sound is programmed to instantly bring the mother Ankylosaurus into defensive action.