archosaurs

Pterosaurs were the first vertebrates to achieve powered flight, doing so roughly 50 million years before birds and 80 million years before bats. At their largest — Quetzalcoatlus northropi, with a wingspan matching a small aircraft — they were the heaviest flying animals in Earth's history. Yet despite sharing the Mesozoic with dinosaurs and appearing in every dinosaur documentary, pterosaurs were not dinosaurs. They were something altogether different.

Dinosaurs did not begin as rulers. They spent the first 30 million years of their existence as minor players in ecosystems dominated by other animals, squeezed into a world recovering from the most catastrophic extinction in Earth's history. Understanding where dinosaurs came from requires understanding the strange, forgotten world they were born into.