A lesson about the timeline of the dino age, from Brian Switek:
Diplodocus, Apatosaurus, Allosaurus, Stegosaurus and their neighbors roamed western North America about 150 million years ago. This slice of time falls in the latter portion of the Jurassic. The traditional representatives of the latest Cretaceous scene—Tyrannosaurus andTriceratops—did not evolve until about 67 million years ago. By themselves, these dates are just labels, but think of them falling along evolution’s timeline. About 83 million years separated Apatosaurus fromTyrannosaurus and Allosaurus from Triceratops. The so-called Age of Mammals—which began when the non-avian dinosaurs were wiped out—has been going on for about 66 million years. Less time separates us from Tyrannosaurus rex than separated T. rex from Stegosaurus.
We like to think of the Age of the Dinosaurs as one, big happy reptile party. But it’s important to realize just how looooooooong they were around compared to the time since the great extinction. We are closer to T. rex than he was to stegosaurus.