Allosaurus is an example of how all life adapts and changes to the environment.
In what's now North America, the larger Allosaurus had given way to the smaller Raptors.
Allosaurus had little trouble dispatching its rivals.
Gigantic dinosaurs like Allosaurus requires larger amounts of food and water to survive.
Allosaurus was perfectly suited for taking on big game.
This suggests that Allosaurus was out-competing Ceratosaurus and ultimately displaced it as the top predator of its time.
We have to remember what was Allosaurus eating.
So in a sense you could say Allosaurus grew big because trees grew big.
But towards the end of Jurassic, we find fewer and fewer skeletons of Ceratosaurus, but more and more skeletons of Allosaurus.
When you look at the foot and the leg of Allosaurus, it's certain quite powerful.
I mean, Allosaurus was a large therapods of its time, one of the top predators.
For 11 million years, Allosaurus ruled what became North America as the biggest predator.
Its ability to adapt allowed Allosaurus to become one of the most successful predators of the late Jurassic.
Then Allosaurus had to grow huge because he prey was becoming so huge.
And at its time, there was nothing as bad as Allosaurus.
But Allosaurus is different. He's got three enormous claws on each hand.
Allosaurus was feeding on sauropods - animals that are multi-times the size of our largest mammals today, the elephant.
Dinosaurs like Allosaurus, Ceratosaurus, Camarasaurus, and Stegosaurus were unable to adapt to these changing environments and it ultimately wiped them from the fossil record.
Allosaurus was a fast, strong, ferocious beast.
Powerfully muscled, Allosaurus was able to hunt huge herbivores, like the two-ton stegosaurus.