From beginnings as skulking, cat-sized reptiles, dinosaurs came to rule Earth for 100 million years – but how? Their secret wasn’t teeth or claws, but something deep inside them
29 July 2020
ABOUT 250 million years ago, a creature raced along the edge of a lake in what is now Poland, leaving prints behind it in the mud. It was a meek and forgettable animal called Prorotodactylus, about the size of a pet cat and with slender limbs. But those prints weren’t the only legacy it left: its descendants somehow became the rulers of Earth.
Those descendants were the dinosaurs. The very word invokes majesty. These were among the most successful groups of animals ever, dominating the planet for more than 100 million years. They proliferated into creatures of all shapes and sizes, some even larger than a jet plane, and filled the land.
Palaeontologists like me were long obsessed with understanding why these mighty animals were snuffed out 66 million years ago. We now know the answer: their days were ended by an enormous asteroid impact. Today, the greatest mystery of dinosaur evolution is how they rose to glory in the first place.
The early descendants of Prorotodactylus would have stuck to the shadows, skulking away from much larger and more fearsome animals. So what was it that allowed them to take centre stage? Piecing together the answer is no easy matter. But over the past few years, a surprising new idea has gained traction. Perhaps the reason for the dinosaurs’ ascendency lies not in their teeth or claws or muscles. It may instead be thanks to a series of strange anatomical adaptations invisible from the outside – adaptations that allowed them to thrive in one of the most extreme periods of climate change the planet …