You are in the coastal mountains of South America, 110 million years ago.

The air was thin and biting at this altitude, a stark contrast to the humid, coastal lagoons you were used to exploring. You were scrambling up the rocky scree of the inland range when a shadow—far too large and strangely shaped to be a vulture—swept over you.

You froze, ducking behind a jagged crag. High above, riding the thermal updrafts with effortless precision, was a Thalassodromeus.

With a wingspan likely exceeding four meters, it was a magnificent, alien sight. The sun glinted off its colossal, brightly colored head crest, which stretched from its beak all the way back beyond its skull like an ancient pharaoh's crown. Unlike the rigid flight of a modern bird, the pterosaur seemed to fly with a kind of reckless agility, weaving between mountain peaks.

It turned, its long, bladelike, toothless beak turning toward the valley below. While its name means "sea runner," this individual wasn't looking for fish; it was watching for prey on the steep slopes, perhaps searching for small reptiles or creatures hiding in the rocky cracks.