You are in the forested plains of North America, 80 million years ago.

The air in the Cretaceous forest was thick, humid, and smelled intensely of damp ferns and pine. You stood frozen behind the massive, rough bark of a conifer, trying to control your breathing. The ground beneath your boots began to tremble—not a rhythmic stomp, but a heavy, thudding vibration.

Through the dense undergrowth, you saw a Xenoceratops. It was roughly the size of a rhinoceros, but far more bizarre than any modern beast, with a heavily armored body covered in scaly skin. It wasn't charging; it was browsing, bringing its parrot-like beak down to snap off a branch of thick vegetation with a sharp crack.

What caught your breath was its head. It was magnificent and terrifying, adorned with a flamboyant frill. You could clearly see the two large spikes jutting out from the top of the shield, and two smaller spikes near its eyes. The intricate cranial ornaments made it look almost alien, a dazzling display of evolutionary art designed for attracting mates or intimidating rivals.

For a moment, its dark eyes turned toward your hiding spot and it froze. The sunlight caught the deep, dark red hue of its horn-covered forehead. It huffed—a noise like a subway steam vent—and stamped a foot to the ground. It lowered its head, presenting that intimidating, spiky frill, and took an aggressive step forward, blowing air and dirt from its nose…