You are in the marshlands of Laos, Asia, 115 million years ago.

The air in the humid jungle was thick with the scent of wet mud and ferns. You were scouting the edge of a slow-moving river, keeping a low profile. Then, you heard it—a resonant thwack followed by a wet splash.

Emerging from the reeds was an Ichthyovenator, a 9-meter, semi-aquatic predator. It was mesmerizing and terrifying. It stood taller than a man, with a scaly, reptilian body that transitioned into a long, powerful tail. What grabbed your attention, however, was its distinct, wavy sail, which dipped lower over its hips before rising again—like two separate sails on its back.

It was waiting.

With incredible patience, it watched the water, its long, crocodile-like snout submerged partially. Its eyes were narrowed, focused on a large ray-finned fish swimming by. Without warning, its long, powerful arm—adorned with massive hooked claws—flashed forward, tearing the water. It didn't need to pierce it with its straight, conical teeth immediately; the sheer force of the claw was enough.

It snatched the prey effortlessly, a swift display of its role as a specialized fish-hunter, far more adapted to this riverine life than a land-based carnivore. You held your breath as the creature submerged, its sail cutting through the water like a fin, moving with a surprising, fluid grace.