The dinosaurs roamed the earth for more than 150 million years. During this time period it was called Mesozoic era.

It is divided into the three time periods in which the dinosaurs lived: the Triassic, Jurassic and Cretaceous.

The Triassic period began and ended with a massive natural disaster which wiped out around 90 percent of the planet's species. The species that did survive then repopulated the Earth and evolved into completely new creatures.

It was a volatile and fertile time, with several natural disasters causing the extinction of many of the world's species, but with enough surviving to evolve into the next wave of life.

Pterosaurs, a group of flying reptiles, dominated the air and the first large mammals and dinosaurs roamed the earth.

The dinosaurs survived the natural disaster at the end of the Triassic period and went on to dominate the Jurassic period. 

The dinosaurs in this period were huge, with the Brachiosaurus standing at 85 feet long, 52 feet tall and weighing 80 tons. 

These massive herbivores were matched with equally large carnivores, such as Allosaurus.