Stegosaurus lived in the late Jurassic period about 150 million years ago.
In contrast, Tyrannosaurus was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event, about 65 million years ago.
Both the Stegosaurus and the Tyrannosaurs are some of the most memorable and recognizable dinosaurs.
We think of them in popular culture as contemporaries. Here is a picture of a fight between a Stegosaurus and an Allosaurus, a relative of the T. Rex.
However, looking closer at the timeline, the Stegosaurus lived 85 million years before the Tyrannosaurus. That means that the Tyrannosaurus lived closer to our current time than to the time of the Stegosaurus. This puts the age of the dinosaurs into perspective. They truly ruled the earth for way longer than mammals ever did.