Rise of dinosaurs down to luck not superiority

Some 230 million years ago, giant reptiles walked the Earth. Some were large and fearsome predators; others were nimble and fleet-footed runners; and yet others were heavily armoured with bony plates running down their backs. Their bodies had evolved into an extraordinary range of shapes and sizes and they had done so at a breakneck pace. They were truly some of the most impressive animals of their time. They were the crurotarsans.