When did dinosaurs live?

The first dinosaurs appeared in the Late Triassic, about 230 million years ago. They lived through the whole Jurassic and Cretaceous, until an asteroid ended their reign 66 million years ago. Only birds, which are dinosaurs too, survived.

That is more than 160 million years. Tyrannosaurus lived closer in time to us than to Stegosaurus: about 66 million years separate T. rex from today, and more than 80 million separate it from Stegosaurus.