Stegosaurus stenops “gigas”

Coloration:
Adult and juvenile (both sexes) - Gray and green mottled body with gray plates. The back plates are thin structures and appear golden yellow in sunlight, with the veins clearly visible. Filled with blood vessels, the plates can be flushed with blood, gaining a red or dark orange tint.

Diet:
Low to medium-growth plants. Stegosaurus prefers tender shoots and other soft vegetable matter due to its simple tooth structure. Like many of the island’s herbivores, Stegosaurus swallows stones to help it digest its food.

Preferred Habitat:
Broken forests and open plains with ample water supply.

Social Structure:
Stegosaurus is a very family-oriented species, living in groups led by an elderly individual. A fellow Stegosaurus doesn’t even need to be in the same herd for it to offer its protection to another. It is often found in herds of four to seven individuals but will also occasionally join up with other families from time to time. Stegosaurus has been known to herd with other animals as  well, if conditions of life call for it.

Description:
Large quadrupedalal herbivore. Stegosaurus is a well-protected animal - its main weapon is its tail, equipped with four lethal spikes (thagomizer), which Stegosaurus can wield with incredible skill. The tail is highly flexible so that the animal can strike predators of any size and in any direction. In addition, the animal's throat is protected by small, bony scutes. The most distinguishing feature of this dinosaur is the double row of large pentagonal plates running down its back. Juveniles have poorly-developed plates and tail spikes. Isla Sorna's Stegosaurus species is much larger than fossil specimens, hence the "gigas" in its name.

Behaviors:
Stegosaurus is one of the most recognizable dinosaurs on Isla Sorna, and probably most famous for its tiny brain, the size of a walnut. Despite its brain size, this dinosaur is mildly intelligent, able to organize defensive strategies and formulating simple plans. Old members of the herd are also able to remember the locations of vital water sources during times of drought, and they are valued by the rest of the herd for their knowledge.

Stegosaurus plates are far too thin and fragile to offer good protection, and are filled with blood vessels which make them susceptible to heavy bleeding if ripped off by a predator. Instead the plates are used for display - when the animal is alarmed or displaying to other Stegosaurus, blood flows through the vessels, creating a vibrant red/orange coloration in the plates. This is to warn or scare carnivores; while males use this ability to intimidate rival males and attract females.

When left alone in peaceful, non-threatening conditions, Stegosaurus is a docile and calm animal, and it will happily browse in close proximity to other herbivores so long as they are respectful of distance. Each herd member remains on the alert for danger. Stegosaurus' eyesight is weak, but it is more than made up for its excellent sense of smell. However, because of its poor eyesight, Stegosaurus is easy to spook. Trace scents left behind by a carnivore that are even days old can make it edgy, and it will respond by bellowing and twirling its thagomizer until the herd finally moves away. Even the scents of dead animals may upset it, as it has learned to associate the smells of dead and rotting flesh with predators and scavengers.

Stegosaurus may also grow agitated by the scents of anything that is remotely strange or foreign. One panicked adult will set off a chain reaction amongst the others of the herd. Therefore Stegosaurus is a dinosaur that is normally best avoided, as it has a tendency to swing its tail at even harmless creatures, particularly those that vaguely resemble two-legged carnivores.

During the breeding season, groups of male Stegosaurus will separate themselves from the main herd in order to take up individual positions away from the females. Once clear of the herd, males begin their displays which involve twirling and swaying of their thagomizers, stamping their feet, bellowing, and flushing blood into their back plates to make them appear a vibrant red. When males get too close to one another and have no room to display, aggression and size is usually the determining factor. Aggressive males win the majority of the time, even when the less-aggressive males are larger. Equal-sized males with the same levels of aggression give one another a wide berth. Conflict usually involves two males shoving against one another in tests of strength. They never use their tails on each other, as their spikes can inflict serious injuries - the smell of blood, along with the sounds of amorous roaring and bellowing, would only attract unwelcome attention.

Female Stegosaurus may visit many males with whom they will mate several times. Once all the breeding females in a herd have mated, the males will rejoin the herd and accompany the females to their preferred nesting grounds. Eggs are usually laid in forested regions, in shallow dips in the ground dug by the female's back feet. The herd remains near the nest site, discouraging predators with their size, plates and thagomizers, and when the young hatch, they are quite self-sufficient, able to feed themselves and move around with the adults. Juvenile Stegosaurus are curious and start to explore their surroundings soon after hatching. They are quite fast-movers, which is a useful survival trait when living amongst a group of large, poor sighted, clumsy adults. While the adults do their best to avoid stepping on the young, accidents do occur, and many of the young perish either by being crushed by an adult, or by moving too far away from the herd and being seized by a predator. As the juveniles grow older, being stepped on becomes less of a problem.

Stegosaurus is fiercely protective of its young as the infants - with their tail spikes being no more than blunt stubs - are particularly vulnerable to attack from predators, especially since they have a tendency to wander from the safety of the adults when exploring their surroundings. However, juvenile Stegosaurus can produce a very distinctive alarm call which provokes any adult Stegosaurus nearby into an immediate defensive reaction.

Stegosaurus herds are nomadic and have no defined territory. They migrate from location to location, stripping one area of plants before moving on to the next.