You are in the forests of South America.

The air in the Cretaceous forest of southern Patagonia wasn't just cold; it felt alive, thin, and biting. I crouched behind the massive, rotting trunk of an ancient conifer, my breath blooming in a freezing mist. You were scouting for fossil traces, but the eerie silence suggested you were not alone.

A rustle. Not in the bushes, but above you.

You looked up just as a shape broke through the canopy—not huge like a T. rex, but built with a terrifying, compact depth of chest that spoke of raw speed and power. It landed on two muscular hind legs, its body shifting with a bird-like agility that belied its five-ton mass. It simply surveyed the area with eyes that seemed to know exactly where you were hiding.

Then it moved its arms. They were monstrous, long, and heavily muscled, topped with white-tipped sickle claws thirty-five centimeters long. It used one to casually tear a massive branch off a nearby tree, the wood splintering like toothpick under its strength. Those weren't just hands; they were instruments of visceral destruction.

It turned its head, the long snout snapping in your direction. You froze, holding your breath as it stalk.