You are in the floodplains of North America, 150 million years ago.

It is dusk. The air in the Jurassic plains was thick, humid, and smelled of rotting vegetation. You have been following the water-laden trail of a herd of Camarasaurus, but a new scent forced you to freeze: a sharp, musky odor that didn't belong to the long-necked herbivores.

Through the mist, about thirty feet away, a Ceratosaurus emerges from the undergrowth. It wasn't the size of a T. rex, but it was built with surprising heft, maybe five meters long. Its most striking feature was a horn on its snout—a ridge of dark, keratinous material that seemed to catch the light—and two smaller crests above its yellow, snake-like eyes. A row of small, bony osteoderms ran down its back and they flex as it steps into the clearing.

Suddenly, the Ceratosaurus snapped its head towards your direction. Its eyes were sharp, focusing on your hiding spot. You held your breath, realizing this was a predator that often scavenged or hunted alone, and you were entirely outmatched. It exhaled, a low hiss that vibrated through the swamp, and took a step forward.