Many types of dinosaurs roamed the earth from about 225 to about 65 million years ago. Different species of dinosaurs flourished then went extinct throughout that entire period. For example, a T. Rex was around much later than the Stegosaurus was.

• From about 206 to 144 million years ago, some of the largest dinosaurs the world ever had were present, such as the Brachiosaurus and Diplodocus.
• From 144 to 65 million years ago, the types of dinosaurs were greater.  Dinosaurs during this time included T. Rex, Triceratops, and a flying Pteranodon.

Once again, a mass extinction occurred around 65 million years ago, bringing the reign of dinosaurs to an end.