You are in the coastal scrublands of New Mexico, 280 million years ago.

The air in the early Permian lands was dry, smelling of red dust and drying river mud. While seeking shelter from the intense midday sun near a canyon wall, you noticed movement near the water's edge.

It wasn't a Dimetrodon—there was no high sail—but the creature was unmistakably dangerous. It was a Sphenacodon, roughly three meters long, looking like a heavily built, ground-hugging lizard. Instead of a sail, it had a prominent, bony ridge running along its back. It stopped, sensing something, and lifted its head, showing a deep skull with an arched snout and distinct, canine-like teeth designed for tearing.

The Sphenacodon focused on a small, fleeing creature near the water, ignoring your presence entirely. It moved with a quick, sprawling gait, its powerful jaw prepared for the hunt, acting as the apex predator of this dusty riverbed.