Because dinosaurs lived so long ago it was very difficult to know how they sounded, how they behaved, their skin color or even how to tell whether a fossil was male or female.

There were lots of different kinds of dinosaurs that lived at different times. Some walked on two legs (they were bipedal), some walked on four (they were quadrupedal). Some were speedy and some were slow and some were armor-plated, some had horns, crests, spikes, or frills. They even had feathers

The dinosaurs went extinct about 65 million years ago, at the end of the Cretaceous period, which was a time of high volcanic and tectonic activity. There are a lot of theories why the extinction occurred. The most widely accepted theory is that an asteroid impact caused major climactic changes to which the dinosaurs couldn't adapt.