You are in the forests of Madagascar, 260 million years ago.

The air in the Late Permian forest was thick, humid, and smelled intensely of sulfur and wet ferns. You stood beneath the towering canopy of a tree, trying not to make a sound. Above you, a tiny, lizard-like creature was clinging to the bark with sharp claws, its horned head flicking side-to-side—a Coelurosauravus.

It wasn't much larger than a modern iguana, but its moth-like membrane wings, held furled against its ribs, made it look incredibly alien. Suddenly, the "hollow lizard grandfather" leaped.

It didn't fall. It spread its ribs, stretching skin membranes into two wide, thin wings. It glided gracefully through the humid air, turning slightly to catch a gust of wind, covering several meters in a steep descent.

It landed deftly on a lower branch, looking for insects, its vibrant, spiky head-frill shining in the filtered sun. For a moment after scrambling up the bark, it stared directly at you…