Pop quiz, hotshot: you’re walking through the woods. It’s a chilly day autumn day. Birds are chirping and a light breeze licks the treetops. You hear a rustling ahead to the right, but before you can even wonder what it is, a Tyrannosaurus bursts through the brush and stares you down from 30 metres away. What do you do?
To answer this question you first need to contemplate a feature of dinosaur anatomy, which has been puzzling paleobiologists for as long as there have been paleobiologists: were dinosaurs warm- or cold-blooded?