You are in the floodplains of North America, 150 million years ago.

The rain wasn't a soft shower; it was a deluge, turning the ferns and conifers of the Late Jurassic floodplain into a shimmering, green blur. You huddled beneath the massive roots of a fallen redwood, shivering, the mud coating your boots. Your breath caught, not from the cold, but from the sound—a deep, resonant thud that vibrationally shook the ground beneath you.

Through the curtain of rain, it appeared. Not all at once, but in pieces. First, the long, slender neck, weaving through the canopy like a living, grey crane, droplets sliding down its textured hide. A Barosaurus.

It was impossibly high, easily over fifty feet, browsing on the tops of conifers you couldn't see from your hiding spot. The sheer scale was suffocating. You held your breath as its head, with a long, low snout and quiet, plant-eating teeth, passed just yards from your tree. It didn't even notice you.