You are in the forests of North America, 50 million years ago.

The air was thick and humid, smelling of wet earth and fermenting ferns. You sat perfectly still behind the massive roots of a Dawn Redwood, your breath caught in your throat. The lush vegetation of the forest floor was suddenly disrupted, pushed aside by a massive, shadowy form.

It stepped into the dappled sunlight of a small clearing: an Uintatherium.

It was magnificent and truly bizarre—far larger than you had anticipated. At roughly 14 feet long and standing nearly 6 feet tall at the shoulders, it resembled an armored, prehistoric rhinoceros, though its feet seemed broader and more like an elephant's. Its back was stout, supported by a heavy neck that carried a massive, peculiar skull.

The animal’s head was adorned with six bony knob-like protrusions arranged in pairs, covered in a velvet-like skin that caught the light. Yet, it was the jaw that frozen you in place. Two terrifying, straight, dagger-like canine teeth—easily 10 inches long—protruded downwards, similar to a sabre-toothed cat. The animal shook its massive head, and a low, gutteral sound rumbled from its throat.