You are in the forests of China, Asia, 164 million years ago.

The humid air of the Middle Jurassic hung heavy, smelling of sulfur from distant volcanoes and dense ferns. You sat perfectly still against a conifer trunk, watching the undergrowth. A sudden movement caught my eye—a creature no bigger than a pigeon scuttled from behind a large rock.

It was an Epidexipteryx. It didn't look like the giant, scaly monsters of popular imagination. This creature was covered in a coat of simple, bluish-green fuzzy, downy protofeathers. It moved in quick, jerky, avian-like motions, its long arms ending in grasping hands—it was likely an arboreal hunter, searching for insects, perhaps using its elongate third finger to dig into tree bark.

The most striking feature was its tail. As it turned, you saw four long, ribbon-like feathers trailing behind it. They weren't like the flight feathers of modern birds, but rather flat, peculiar plumes used solely for display, swaying with every motion. The creature paused, looking toward a nearby clearing, its large eyes scanning for danger. While it possessed "display feathers" on its tail, it was clearly flightless, a tiny, specialized runner in a world dominated by giants.