Tyrannosaurus

## *Tyrannosaurus rex*

### Description

Gigantic predatory dinosaur with tiny arms, powerful jaws with bone-crushing teeth, and large muscular legs

## Physiology

### Attributes

Large body with a massive head; two small arms (each one ending in two clawed fingers); powerful jaws; long, muscular legs; bone-crushing teeth; long, heavy tail; quick speed; tremendous strength

## Biography

### Time

90 to 65 MYA

***Tyrannosaurus*** (name meaning "*Tyrant Lizard*"), often referred to as its full name ***Tyrannosaurus rex*** or commonly abbreviated simply to ***T. rex*** for short, is a genus of tyrannosaurid theropod dinosaur that originated during the Late Cretaceous period in what is now North America. A large, territorial, and powerful bipedal carnivorous dinosaur that measured 15 meters long, stood 6 meters tall, and weighed over 7 tons, *Tyrannosaurus* was the largest terrestrial carnivore of all time, dwarfing other predatory dinosaurs and was also the largest of the tyrannosaur family of dinosaurs. The undisputed "*King of the Dinosaurs*", *Tyrannosaurus* is arguably the world's most famous and popular dinosaur ever to live on Planet Earth, known for its cultural impact amongst prehistoric creatures, let alone, dinosaurs.

One of the primary animals that extinct in Cretaceous–Paleogene extinction event, in the Series 1 finale, "*End of the Road*", a family of *Tyrannosaurus*, including a large female named Sue, had became extinct at prehistoric Montana 65 million years ago.

## Facts

### Era & Discovery

Perhaps the most well-known dinosaur in the world and the undisputed king of the dinosaurs, *Tyrannosaurus rex* first appeared in North America during the Late Cretaceous Period around 90 million years ago. It lived throughout western North America up until the very end of the Cretaceous Period 65 million years ago alongside dinosaurs and other creatures like *Ornithomimus*, *Dromaeosaurus*, *Troodon*, *Deinosuchus*, *Quetzalcoatlus*, *Pteranodon*, *Nyctosaurus*, *Didelphodon*, *Dinilysia*, *Edmontosaurus*, *Triceratops*, *Parasaurolophus*, *Torosaurus*, *Ankylosaurus*, *Pachycephalosaurus*, and *Thescelosaurus*. Ruling the Earth for some 25 million years as the apex predator of the world, it died out with all the other dinosaurs and other prehistoric creatures at the end of the Cretaceous Period. It was among the last dinosaurs to exist prior to the Cretaceous-Tertiary extinction event.

Henry Fairfield Osborn, president of the American Museum of Natural History, discovered *Tyrannosaurus rex* by Arthur Lakes near Golden, Colorado in 1874 and named the dinosaur in 1905. Since their first discovery, more than 50 specimens of *Tyrannosaurus rex* have been identified, some of which are nearly complete skeletons, which has allowed significant research into many aspects of its biology, including its life history and biomechanics. Over the years since they were first discovered, *Tyrannosaurus rex* has been regarded as the best known and most famous of all prehistoric creatures, let alone dinosaurs, in the world.

### Physical Attributes

 File:WWD Tyrannosaurus.jpg
The largest member of the tyrannosaur family of dinosaurs, *Tyrannosaurus rex* was among one of the largest, if not, the largest theropod dinosaur ever to walk the Earth, reaching various large sizes. On average, a fully grown individual *Tyrannosaurus* weighed up to 7 – 14 tons (15,000 – 30,000 lbs.), stood approximately 12 – 18 feet (3.7 – 5.6 m) tall, and measured over 40 – 47 feet (12.3 – 14.5 m) in length, rivaling the sizes of the earlier *Giganotosaurus* from South America as well as the *Spinosaurus* and *Carcharodontosaurus* of North Africa. However, the largest *Tyrannosaurus* ever discovered weighed in at up to a staggering 18 tons (39,000 lbs), grew up to reach a height of 20 feet (6.2 m) tall at the hips, and reached a staggering measurement of 50 feet (15.3 m) in length from its snout to the tip of its tail, therefore making *Tyrannosaurus* larger than any other theropod dinosaur as well as arguably the largest terrestrial carnivore of all time. *Tyrannosaurus rex* was a deadly predator a massive, 5 foot (1.52 m) long skull that had a standard tyrannosaur build: small two-fingered and clawed forearms; a strong, muscular body balanced by a long, heavy tail; two, very large, strong, and powerful legs; and a large and powerful head with banana-sized teeth.

*Tyrannosaurus rex* was the dinosaurs most infamous and ultimate predator that appeared in the last 20,000,000 years of the Cretaceous Period. They were giant carnivorous dinosaurs that stalked the landscape and, being the most notorious flesh-eaters ever known, they were specifically and perfectly evolved to kill and eat even other giant dinosaurs, even ones larger than *T. rex* itself. The brain of *Tyrannosaurus rex* was well developed, which gave it excellent senses sight (comparable to that of a bird of prey), great hearing, and advanced olfactories that allowed *Tyrannosaurus* to efficiently smell prey from over four miles away.

Like their smaller cousin, *Albertosaurus*, *T. rex* was a very hard dinosaur to outrun and chase down. Despite their immense size and heavy-weight, *T. rex* were relatively fast and agile dinosaurs, capable of breaking into surprising bursts of speed and often achieving speeds of over 25 – 35 (40 – 56 km/h), even reaching 45 mph (72 km/h) if they needed to, thanks to some of its bones being hollow, and were also capable of catching fast-moving prey including *Ornithomimus* and *Edmontosaurus* as well as tackling large and sturdy dinosaurs like *Triceratops*. Relative to the large and powerful hind limbs, *Tyrannosaurus* forelimbs were small and retained only two digits. Recent specimens have shown the tiny arms to have been well-muscled, presumably to enable the animal to anchor itself to the ground as it attempted to straighten its hind legs and stand up from a prone position.

Additionally, *T. rex* also had another advantage over other carnivorous dinosaurs of a similar size: its bite. It has been discovered that *Tyrannosaurus rex* also possessed a biological weapon. Its 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. The primary weapon of a *Tyrannosaurus* was their mouth. Their arms were rather small so they could carry a massive jaw and remain balanced on their legs.

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 7 tons (15,432 lb) of pressure, well over 10 times more powerful than a lion's bite force, therefore making it among the strongest bite force in the animal kingdom. Its jaws alone were 1.2 meters long and 1 meter wide filled with 50 sharp, serrated bone-crushing teeth that 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. The teeth were used to grip prey, breaking bones, puncturing arteries, and rupturing many organs. *Tyrannosaurus* could have also had toxic spit that it used to bring down animals. These jaws could crush bone and tear off up to 70 kilograms of meat in a single bite at a time. This could be very dangerous, though, as it could potentially choke to death. It had jaws strong enough to crush even the armor of an *Ankylosaurus*.

Its intelligence was also staggering. With a brain comparable to that of a modern day simian and with only one e.q point bellow chimpanzees its possible they could have displayed complex social behaviour. And amazing hunting strategies. [1]

#### Capabilities and Weaponry

* **Raw Strength:** In addition to being physically a tremendously strong dinosaur, *T. rex* could lift over 5 tons with its powerful jaws. They could charge their own body weight against their enemies, ramming them like a freight train.
	+ **Jaw Strength:** Having the bite force of 15,000 pounds PSI, the teeth and jaws of *T. rex* are perfectly designed to crush armor and bone.
* **Speed:** Despite their giant size, *T. rex* was considerably fast, able to reach speeds in excess of 25–35 mph (40–56 km/h) by using their long, powerful, and muscular legs. However, if they were hungry or determined enough, they can also reach speeds as fast as 45 mph (72 km/h) if they ever needed to.
* **Agility:** In addition to their relatively quick speed, *T. rex* is quite agile for their size, able to make sharp turns within a couple of seconds.
* **Senses:** *T. rex* relies strongly on its powerful sense of smell and hearing to find prey. They have also had powerful binocular eyesight, comparable to that of a bird of prey.
* **Bacterial Bite:** In addition to their remarkably powerful jaws and bone-crushing teeth, *T. rex*, much like the Komodo dragon, was said to have a mouth full of diseases that could kill its victims.
* **Intelligent:** *T. rex* is said to be as smart as an ape, if not smarter, and to have the brain size of a gorillas brain. Knowing of their large size, packs of smaller predators will leave the baby rexes alone. The cerebrum of *T. rex* was larger than most dinosaurs, indicating that they were able to think through things more efficiently, identical to raptors.
* **Roar:** The roar of a *Tyrannosaurus rex* can be heard over 7 miles away while being rooted.
* **Hunting:** *T. rex* can hunt by themselves or in a family group and occasionally scavenge.
* **Combat Abilities:** Mostly, *T. rex* used their powerful jaws to bite its enemy or prey. It can also use its long powerful legs to kick and their large tail to whip as well if the enemy is near the tail. *T. rex's* head can be useful as a headbutt. They can even use their own body charge at its enemies, like a 7-ton battering ram.
* **Durability and Stamina:** *T.rex*, large size and fully grown, are able to take many blows from other dinosaurs that are able to still fight back because of their tough skin.

### Behavior & Traits

Like many predatory 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 several individuals, including juveniles and even 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 *Tyrannosaurus* had enormous territories of hundreds of square kilometers, some *T. rex* packs usually made their dens in mountain or alpine regions, which is typically full of bones from various dead animals scattered all over. Like modern birds and lions, *T. rex* brought food back to their territory to avoid potential fights from rivals. In the home of a *T. rex*, the juveniles (be it hatchlings or adolescents) often fought over the scraps of food.

Though *T. rex* itself had no predators, the unborn would fall victim to air pollution from nearby volcanoes that prevented their eggshells from forming correctly and nest raiders, like *Dromaeosaurus* and the mammal *Didelphodon*. There were no known predators of *Tyrannosaurus*. However, whilst they were wary of dinosaurs like the armored *Ankylosaurus*, the only dinosaurs *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.

When it came to mating, females would attract males by emitting loud calls, broadcasting the noise even for weeks for a male. The males responded to these calls by giving the female an animal carcass as a gift to appease her rather than to satisfy their own hunger. Sometimes, the male would have too call the female on certain occasions when he had a kill for her. When the females arrived at those males, they did seem weary at first. If she liked the gift, she would be submissive to the male. The two would then proceed to have a mating period that would last three days with the male being beside his mate at all times to prevent any other male *Tyrannosaurus rex* from mating with her. Afterward, the female *Tyrannosaurus* would lay her eggs in a mound-shaped nest, much like modern crocodilians.

*Tyrannosaurus* females were capable of laying a maximum of 12 eggs, but normally only got one to three chicks at most and rarely more than that, mostly because other eggs are taken by scavengers. *Tyrannosaurus* eggs were the size of a mango and bird-like. During the incubation period, the *Tyrannosaurus* mother would camouflage and guard their nests to prevent any nest raiders, such as little Cretaceous mammals, *Dromaeosaurus*, and *Ornithomimus*, from eating their eggs, even to the point of denying themselves food or water for two months just to make sure their nest was protected.

After their young were born, *Tyrannosaurus* mothers would end their fasting period and would give the juveniles any remains left from their kills. *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 growing from sub-adult to adult, siblings would become extremely aggressive and would often fight. It was common for siblings to kill each other. Despite this, the parents would break up those fights if they got too violent.

## Trivia

* *Tyrannosaurus rex* was originally called *Manospondylus* (name meaning "*Giant Thin Vertebrade*").
* *Tyrannosaurus rex* is the largest and strongest theropod dinosaur, as well as terrestrial carnivore, ever brought to the museum.
	+ *Tyrannosaurus rex* was the last and largest tyrannosaur brought to the museum.
	+ *Tyrannosaurus rex* is the most famous dinosaur of all time.
* Measuring 15 m (50 ft) long, the *Tyrannosaurus rex* featured in the series is larger than Scotty, the largest known *Tyrannosaurus* specimen, who measures in at 13 m (43 ft) long.
* Despite their minuscule arms, *Tyrannosaurus* were excellent swimmers.
* Additionally, despite their small arms, *T. rex* had powerful arms that could lift 400 pounds in real life.
* They are depicted as featherless. In reality, adults may have had small amounts of feathering covering their bodies while chicks almost certainly possessed a coat of fuzzy feathers to stay warm. Though this is still contreversial and slightly dubious.
* The sound effects of *Tyrannosaurus rex* portrayed in the series are that of crocodile, lion, and tiger sound effects.
* *Tyrannosaurus rex* is the only dinosaur that is usually referred to with its binomial name.
* Also very controversialy the tyrannosaurus in the show is shown to be lipless. as Many great scientists opose this idea.