You are in the grasslands of South America, 3 million years ago.

The air near the bank was damp and smelled of mud. While scouting for more megafauna, you stopped dead in your tracks, your heart hammering against your ribs. Through the tall, whispering pampas grass, you saw a domed shape, dark and vast, moving with a slow, grinding patience. It wasn't a boulder—it was moving.

It was a Glyptodon, larger than the largest bison, its carapace a patchwork of thick, interlocking bony plates, like a fortress on legs. It was chewing lazily on riverside shrubs, seemingly unaware of you. As it turned, you saw its tail—long and armored with spikes, trailing in the mud like a morningstar weapon. The ground itself seemed to vibrate as it continued its slow, quiet grazing.