Tyrannosaurus

### Description

Giant theropod dinosaur with large head, powerful jaws with bone-crushing teeth, small arms, powerful legs, and long tail.

### Family

Tyrannosauridae

***Tyrannosaurus*** (name meaning "*Tyrant Lizard*"), also called ***Tyrannosaurus rex*** or commonly abbreviated to ***T. rex*** for short, is a genus of tyrannosaurid dinosaur that originated during the Late Cretaceous period in what is now North America. The undisputed "*King of the Dinosaurs*" and the largest tyrannosaur species, *Tyrannosaurus rex* is arguably the world's most famous dinosaur as well as the largest theropod dinosaur and terrestrial carnivore of all time.

Thought to have been extinct for 65 million years, there are still some that remain alive on Primeval Island.

## Facts

### Era & Region

*Tyrannosaurus rex* first appeared in North America during the Late Cretaceous period around 86 million years ago. And it lived through to the end of the Cretaceous period 65 million years ago. Earning the title "*king of the dinosaurs*", they ruled the Cretaceous as the world's apex predator for 20 million years. They shared their environments with dinosaurs like *Ankylosaurus*, *Pachycephalosaurus*, *Parasaurolophus, Corythosaurus*, *Struthiomimus*, *Triceratops*, and *Dakotaraptor*.

### Discovery & Range

*Tyrannosaurus* was first discovered and named in 1905 by Barnum Brown. Since then, their remains have been found in several regions of North America; such as Montana as well as Wyoming, Colorado, New Mexico, South Dakota, and Texas. Canadian provinces like Alberta and Saskatchewan. There have even been finds in Mexico.

### Physical Description

The largest member of the tyrannosaur family of dinosaurs, *Tyrannosaurus rex* was also among the largest theropod dinosaurs that ever walked the Earth. On average, they weighed around 5 – 7 tons (11,000 – 15,000 pounds), stood 15 – 16 feet (4.7 – 5 m) tall, and measured 40 – 43 feet (12.8 – 13.2 m) long. However, colossal individuals have been discovered to have weighed in at up to a staggering 7.5 tons (16,000 lbs.), grew up to stand 20 feet (6 m) tall at the hips, and measured a staggering 50 feet (15 m) in length from its snout to the tip of its tail. This makes *Tyrannosaurus rex* arguably the largest terrestrial carnivore of all time.

*Tyrannosaurus rex* was a deadly and powerful predator that had a standard tyrannosaur build: very small, two-fingered and clawed forearms; a strong, muscular body balanced by a 20-foot-long, heavy tail; two, very large, strong, and powerful legs; and a massive and powerful 5 foot (1.52 m) long head with banana-sized teeth. Due to its immense size, T. rex was a very strong dinosaur, enough so that it could lift prey heavier than 5 tons with only its mouth. Also, despite their heavy-weight, *T. rex* were very fast runners, able to reach speeds of up to 45 mph.

*T. rex* also possesses remarkably powerful jaws that measured 3 feet long. The heavily reinforced skull of T.rex suggests that it was a devastating predator, with bone-crushing bite strength. T. rex had massive mussels in their jaws that gave them a bite force that was upwards of 6 tons (13,227 lb) psi, well over 10 times more powerful than that of a lion's bite force, therefore making it among the strongest bite forces in the animal kingdom, perhaps the most powerful bite force of any terrestrial animal ever discovered. In addition, it also had 50 sharp and serrated bone-crushing teeth. These teeth were like thick pegs, larger than a human hand, some being close to 13 inches (150mm) in length (with the root included) that could go through most prey, including their bones. With these traits, these predatory dinosaurs could crush right through the bones of even the armored ankylosaurs. When feeding, *T. rex* could eat as much as 500 pounds in one bite.

Additionally, *T. rex* also possessed a biological weapon. Possessing a toxic spit that it used to bring down animals, a *T.rex's* bite could cause infections and diseases like septicemia, therefore their bites induced a vast amount of bacteria onto its victims, much like that of a Komodo dragon.

### Behavior Traits

Like many theropod dinosaurs, even ones of their immense size (though it has been shown to be a solitary hunter), *Tyrannosaurus rex* often traveled and hunted in packs, ranging from pairs to a small group of around several individuals, including juveniles and hatchlings. *Tyrannosaurus* was also a generalist hypercarnivore with no real preferences: its prey consisted of the many herbivores in the area, including ankylosaurs, ceratopsians, pachycephalosaurs, ornithopods, as well as its favorite prey the hadrosaurs, and even the mighty sauropods. *Tyrannosaurus* hunted its prey using stealth and cunning surprising for such a large animal. Once it locked its sights on a prey item, *Tyrannosaurus* pursued its victim swiftly and silently despite its large size, with little chance of escape. *T. rex* was so deadly that its very presence could be disturbing to some smaller animals, who would go into a state of complete silence when the predator was nearby.

Though *T. rex* itself had no predators, they were wary of dinosaurs like the armored Ankylosaurus. Additionally, the only thing that a *T. rex* was truly afraid of was another, larger individual of their own species who were willing to commit cannibalism. Like all reptiles, *T. rex*, at times, were cannibalistic, eating not only their own kind but hatchlings as well, given the chance. *Tyrannosaurus* was also very aggressive and territorial, with the females being the largest and most aggressive.

*Tyrannosaurus* females were highly protective of their offspring and would find food for them, even at the cost of her own life. The young were able to get their mother's attention by chirping. If a juvenile was in any danger, it would call out to its mother for help. Therefore, she would fight off even other members of her species in order to protect her young, even if she was wounded. The mother would still protect her chicks even if it killed her in the process. And the more an adult female *T. rex* protected her offspring, the better chances they had at survival.

*Tyrannosaurus* siblings were extremely hostile towards each other. When juveniles, siblings would commonly play-fight. However, when sub-adult to adult, siblings would become extremely aggressive and would often fight. It was common for siblings to kill each other. However, the parents would break up those fights if they got too violent.

## Trivia

* The sound effects for the *T. rex* are that of The Land Unknown T.rex as well as some lion, tiger, bear, crocodile, some Godzilla sounds, and the T-rex from Jurassic Park and Jurassic World.