THE dinosaurs dominated life for 135 million years during Earth’s Jurassic and Cretaceous periods, but only because they got lucky. They were also-rans to their crocodilian cousins until climate change wiped out the competition.
Near the start of the Triassic period, 250 million years ago, the reptilian archosaurs split into the dinosaurs and the crurotarsans, whose only living descendants are the crocodiles. Palaeontologists used to think dinosaurs dominated the last 30 million years of the Triassic, and to do this they must have been better adapted. In fact the two groups are very similar, and many of the “dinosaur” fossils…
