Dinosaurs: Almost Everything You Learned Is Out of Date

Dinosaur knowledge has a strange quality: most adults are working from a picture book they read at seven, updated once by a film in 1993. Both are now badly out of date.

The timeline nobody believes

Stegosaurus lived roughly 150 million years ago. Tyrannosaurus rex lived roughly 68 million years ago. That is a gap of over 80 million years — which means T. rex is closer in time to you, reading this, than it ever was to Stegosaurus.

People routinely picture them fighting. They missed each other by a span longer than the entire age of mammals.

The feathers

Velociraptor was not the man-sized reptile stalking a kitchen. It was roughly the size of a turkey, and the fossil evidence indicates it was feathered. So were many of its relatives. The scaly, lizard-like dinosaur of old illustrations has been steadily replaced by something that looks far more like a bird — because that is what it was closer to.

They are not extinct

This is the part that still catches people. Birds are dinosaurs — specifically, they are the surviving branch of the theropods, the same group that produced T. rex. The non-avian dinosaurs died out around 66 million years ago, most likely following an asteroid impact at Chicxulub, off what is now Mexico. The avian ones are outside your window.

Things that were not dinosaurs

Pterosaurs, which flew, were not dinosaurs. Plesiosaurs, which swam, were not dinosaurs. Neither was the Dimetrodon with the sail on its back, which is closer to your ancestors than to T. rex. "Dinosaur" is a specific group, not a synonym for "big extinct reptile" — and quizzes love this distinction.

The woman who found them first

Mary Anning was pulling ichthyosaur and plesiosaur fossils out of the cliffs at Lyme Regis in the early 1800s, at a time when the Geological Society would not admit her as a member because she was a woman. Much of what she found was published by men who did not credit her. The scientific establishment has since caught up, roughly two centuries late.

The word "dinosaur" itself was coined in 1842 by Richard Owen, and means "terrible lizard" — which, given what we now know about the feathers, has aged about as well as everything else on this list.