Tyrannosaurus

Time Period
 Diet

Despite being a carnivore, Tyrannosaurus was second to Triceratops as the most abundant dinosaur genus in the Hell Creek formation.. Tyrannosaurus was a generalist: not partial to any sort of habitat and would readily feed on whatever suitable prey was available in it's environment.

T.rex growth was slow until they underwent a massive growth spurt around 15 years of age that continues until around 18 years of age. The juveniles were thin and gracile while the adults were bulkier and more robust.

## Ecology in DinoSystem

Tyrannosaurus is Dinosystem's largest carnivore. They are capable of bringing down adult Triceratops but prefer juvenile trikes and juvenile Ankylosaurus. Tyrannosaurus will readily scavenge whatever carrion they find if the opportunity presents itself, even the corpses of other Tyrannosaurus. They do not tolerate smaller carnivores, like Troodon or younger Tyrannosaurus that are not their own young, scavenging from carcasses that they have claimed and they will carry smaller bodies away from other adult Tyrannosaurus. A mother T. Rex will tolerate their young feeding on carcasses even for some time after they are no longer caring for them, however.

Males are dark green while females are brownish with slightly greater bulk. Rutting males will migrate in the mid-late winter, in search of a female in heat, often ignoring prey and forgoing sleep until exhausted. Even after killing prey, they will abandon the carcass soon after feeding to continue looking for a mate. Prior to mating, if the population of Tyrannosaurus is high for the size of the island, they may fight briefly to test the strength of their potential mate. If the male loses, the female will reject them, though they may still try again later. If the female is sufficiently hungry when the male finds them, they may reject mating outright for the year and end the male's rut early.

Upon mating, a female will choose a nest site to lay her eggs, usually under a tree. She will then stand guard without leaving until they hatch; not even to hunt. They will still readily take advantage of nearby carrion or water, but if those are not available then she may eat one of her own eggs once she begins to starve. Upon hatching, the young are capable of scavenging on their own and may also hunt Didelphodon. If the young cannot find food, then the mother may regurgitate meat for them provided that she has enough stored in reserve. They remain with their mother until they are 25 days old or if the mother mates again before this time, but if the mother dies the young can usually fend for themselves. Tyrannosaurus reaches maturity at 38 days old and has a maximum lifespan of 142 days.

Youngsters can kill very young Ankylosaurus and Triceratops but older animals are too much for them to handle.

Tyrranosaurus plays an important role in preventing the overgrazing and extinction of plants on the island, as they prefer to wander in more lush environments.

## Strategy in Dinosystem Survival

Both adult and young Tyrannosaurus will readily attack the player, but if a player can injure a Tyrannosaur enough then it will retreat. However the adults are much harder to injure while youngsters often hang around by their mothers. Though adults do far more direct damage than youngsters, the injuries caused by a youngsters should not be taken lightly.

A Tyrannosaur is a source of meat if the player can kill it. Youngsters are far easier to hunt but their mothers will aggressively protect them. Fortunately youngsters often wander away from their mothers when in search of food.

Tyrannosaurus eggs can also be eaten, but the protective mother guards them and rarely leaves them alone. So, unless starving, it's probably best to avoid a Tyrannosaurus nest.

Adult Tyrannosaurus have a chance to pick you up instead of attacking and continuously damage you before throwing you away.

## Resources

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3049066/

http://science.sciencemag.org/content/313/5784/213

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0026037