Dinosaurs aren’t dead. Not completely. Birds carry on their Mesozoic legacy. But all the forms that inspire our dreams and nightmares – the tyrannosaurs, ceratopsids, sauropods, and their ilk – are all gone. They were wiped out in a blink of geologic time, roundabout 66 million years ago. How could a lineage as long-lived, diverse, and widespread as the non-avian dinosaur be exterminated so thoroughly?

As a little dinomaniac growing up in the 80s, the answer seemed simple. An asteroid struck the planet and struck down the dinosaurs in a stroke of cosmic bad luck. All the documentaries I begged my parents to tape for me were agreed on this point.

Stephen Brusatte, a paleontologist at the University of Edinburgh, grew up