Allosaurus

## *Allosaurus fragilis*

### Description

Large predatory dinosaur with red crests over its eyes and three-fingered hands with sharp claws

## Physiology

### Attributes

Large streamlined shape for killing dinosaurs; red crests over eyes; sharp teeth; three-fingered hands with sharp claws

## Biography

### Time

156 to 145 MYA

***Allosaurus*** (name meaning "*Different Lizard*") is a genus of theropod dinosaur that originated during the Late Jurassic period in what is now North America, Europe, and Africa. The apex predator of its time, credited as the "*Lions of the Jurassic*", *Allosaurus* was a strong, ferocious carnivore. Measuring 11 meters long, standing almost 5 meters tall, and weighing 5 tons, *Allosaurus* was one of the largest theropod dinosaurs as well as one of the world's best-known prehistoric animals.

One of the primary animals of the prehistoric earth, *Allosaurus* was first encountered in the Series 1 episode "*Survival of the Biggest* ", in which a pair of them lived in their lifes from Late Jurassic of 150 million years ago.

## Facts

### Era & Discovery

*Allosaurus* lived in North America, Europe, and Africa during the Late Jurassic Period from 156 to 145 million years ago. Often credited as the king or "*lion of the Jurassic*", *Allosaurus* was the largest and apex predator of its time. Ruling the Jurassic for 11 million years, it shared its environment with other creatures like *Ceratosaurus*, *Ornitholestes*, *Anurognathus*, *Brachiosaurus*, *Diplodocus*, *Apatosaurus*, *Camarasaurus*, *Stegosaurus*, *Dryosaurus*, and *Othnielia*.

*Allosaurus* was first discovered by Othniel Charles Marsh in 1877 and has since become one of the most famous dinosaurs in the world. *Allosaurus* was among the largest predatory dinosaurs of the Late Jurassic and was also among the largest predators until the Tyrannosaurs appeared over 50 million years later. *Allosaurus* specimens have been found in Colorado, Utah, Wyoming, and Montana as well as Poland and Tanzania.

### Physical Attributes

As the largest theropod dinosaur of its time and the first giant predatory dinosaur ever to walk North America, *Allosaurus* was a large carnivorous dinosaur. In fact, on average, measuring 30 – 40 feet (9 – 12 m) long, standing 13 – 16 feet (4 – 5 m) tall, and weighing up to 3 – 5 tons (6,000 – 10,000 lbs), *Allosaurus* was one of the largest carnivorous dinosaurs that ever walked the Earth. However, the largest *Allosaurus* ever discovered stood about 16.5 feet (5 m) tall, measured 45 feet (13 m) in length, and weighed up to 6.5 tons (13,000 lbs.), making it a huge carnivorous dinosaur almost as large as *Tyrannosaurus rex*.

Even at that large, *Allosaurus* was such a massive predator, but they were just as fast, quick, and agile as their two little ancestors: *Coelophysis* and *Liliensternus*. *Allosaurus* had to eat their own weight in food every month, which is equivalent to about as much as over 40 humans. From the moment they hatch from their eggs, an individual of *Allosaurus* could reach their full adult size in just seven short years, give or take.

*Allosaurus* had a skull that measured three feet long, with a pair of blunt crests just above its eyes, in the orbital region. *Allosaurus* also had large, powerful jaws line with over 70, long, sharp, serrated teeth that were 2–4 inches long. Movable joints and elastic ligaments in *Allosaurus* jaw and skull flexed to help the teeth tear and slice through the prey. The flexible jaws stretched widely to allow the creature to swallow large mouthfuls of flesh. These teeth were curved inward, shaped like a "V" to help secure its prey.

*Allosaurus* had a bulky body, a massive tail, and thick bones. It had a strong S-shaped neck and had vertebrae that were different from those of other dinosaurs, hence its name. Running on two muscular, bird-like legs at speeds as fast as 20 mph, *Allosaurus* preyed upon the large herbivores of the period, including large sauropods, and smaller plant-eaters. The forelimbs were short but muscular and had three-fingered tipped hands with a sharply curved claw up to 15 – 25cm (6 – 10 inches) long for holding prey.

#### Capabilities and Weaponry

* **Claws:** *Allosaurus* killed its prey with the sharp talons on its arms and legs.
* **Speed:** *Allosaurus* was a fast dinosaur, able to run at speeds in excess of 20 miles per hour.
* **Strength:** Despite its weaker jaws strength, *Allosaurus* was also a very physically strong dinosaur, able to toss anything that ways 2 tons.
* **Teeth:** *Allosaurus* possessed sharp, saber-like teeth.

### Behavior & Traits

Like many large predators, *Allosaurus* was a pack hunter, possibly lying in wait to ambush prey. It could hunt in pairs, packs of three (which was their most common number), groups, or even numbers of over half a dozen individuals. When hunting smaller prey, like *Dryosaurus*, even a single *Allosaurus*, be it adult or juvenile, could rush in on the group, attack and kill any selected member it could catch. But when hunting larger prey, such as a herd of *Diplodocus*, the *Allosaurus* pack would split up in between a *Diplodocus* herd, literately running through and around the herd, break it up, and eventually isolate the young, old, weak, sick, and injured members of the herd.

When the hatchlings of female *Allosaurus* were born, the smell was important to *Allosaurus* and from the moment the mother and hatchling *Allosaurus* smelled each other, they formed a bond that was crucial to the hatchlings early survival. Hatchling *Allosaurus* ate insects and other small animals.

As young *Allosaurus* reached their first to the second year of life, they grew to almost 10 feet (3 m) and, by then, would no longer be hunting insects, but hunting other, smaller herbivorous dinosaurs, such as *Dryosaurus* and *Othnielia*. Despite that, they were still small *Allosaurus* and they were not a match for almost all other dinosaurs on their environment, such as a female *Ornitholestes* protecting her nest.

By the time a juvenile *Allosaurus* was five years of age, they already reached about 30 feet (9 m) long, however, they were not yet fully grown. Despite that, they were old enough and large enough to hunt larger dinosaurs, such as *Stegosaurus* and even the large sauropod dinosaurs like *Diplodocus*.

When *Allosaurus* lived to be six years old, as a sign of age, the crests over their eyes would gain a darker shade of red. Sexual maturity was dependent on an *Allosaurus's* size and at 33 feet (10 m) long, young *Allosaurus* were well on their way to be big enough. However, even by that time, they were actually mature adolescents rather than full-sized adults.

Upon *Allosaurus* reaching their full size, they quickly established their dominance over predatory dinosaurs, especially other *Allosaurs*. When gigantic predators get to the size of a fully grown *Allosaurus*, most of those predators rarely had to bring down their own food. They just scavenged other kills.

## Trivia

* *Allosaurus* was the very first giant predatory dinosaur to be brought to the mesuem, which is coincidental since it was the very first giant predatory dinosaur ever to walk North America.
* The sound effects for the *Allosaurus* are that of a lion, altered vulture sounds, and some classical ambient dinosaur roars and used t rex from jurassic park
	+ Lion sound effects seem to fit well for *Allosaurus*, since they are described as being the "*lions of the Jurassic*".