Footprints in the muds of time

dinosaurs' rise. That is the thesis proposed by Paul Olsen of Columbia University. Dinosaurs first appear in the fossil record 230 million years ago, during the Triassic period. But they were mostly small, and they shared the Earth with lots of other sorts of reptile. It was in the subsequent Jurassic period, which began 202 million years ago, that they overran the planet and turned into the monsters realistically depicted in modern books and movies. Dr Olsen and his colleagues are not the first to suggest that the dinosaurs inherited the Earth as the result of an asteroid strike, But they are the first to show that the takeover did, Indeed, happen in a geological eye blink.