You are in the desert riverbanks of North America, 220 million years ago.

The heat of the Triassic sun was punishing, turning the scrublands into a shimmering haze. You crouched behind a thicket of ferns, your breath shallow, watching the riverbank. It was the only water for miles, and you weren’t the only one waiting for it.

The ground began to rumble, not with thunder, but with the rhythmic stomping of massive, barrel-shaped bodies. A herd of Placerias was emerging from the treeline.

There were ten, maybe fifteen of them, looking like prehistoric, scaly hippos dressed in shades of brown. They moved slowly, almost lazily, but you knew better than to be fooled. A single, dominant male led the group, his snout sporting a pair of thick, downwards-pointing tusks that shone with saliva. These weren't teeth; they were bone-extensions, sharp enough to dig for deep roots—or to tear a predator in half.