You are in the forests of South America, 230 million years ago.

The air in the Triassic basin was thick, humid, and smelled of volcanic ash and wet ferns. You paused near a rushing river bank, checking the map. That’s when the silence hit—the abrupt lack of insect noise.

Something small, like a Pisanosaurus, darted across the mud, then stopped. It didn’t look at me; it looked at the canopy of tree ferns above.

A sharp, rattling shriek broke the quiet. It dropped from the foliage—not with the weight of a giant, but with the terrifying speed of a predatory lizard. It was about 15 feet long, its long, thin skull swinging side-to-side.

It was a Herrerasaurus. Its hide was mottled brown and green, allowing it to vanish in the light-dappled mudflats. It didn’t walk with the upright rigidity of a T. rex; it seemed agile, almost feline, moving swiftly on its toes.

The beast turned its snake-like head toward you, its eyes fixed, looking less like a modern bird and more like a massive, primitive ancestor to the crocodilians. It snarls, revealing its serrated teeth in its narrow, snapping mouth.