Ask any obsessive dino-phile above kindergarten age to explain the dinosaur family tree and it’s likely the first thing you’ll hear is that all dinosaur species fall into one of two groups. It’s a core concept upon which our entire understanding of dinosaurs is built. But according to a new study, we got that most fundamental aspect of dinosaur evolution completely wrong. Oops.
For more than a century, the dinosaur family tree was understood as having a very early split into two branches: