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

The air in the Late Jurassic plains was thick and humid. You crouched behind a cycad, the mud clinging to your boots, as a low, resonant thrumming vibration traveled through the earth.

Then, they appeared.

It wasn't a herd of massive Brachiosaurus, but something more graceful—a herd of Dicraeosaurus. About a dozen of these mid-sized sauropods emerged from the fog-draped tree line. They were only about 40 feet long, much smaller than their massive cousins, but their necks were incredibly long and slender, adorned with a subtle, split-spine ridge running down their backs.

The herd was quiet, browsing purposefully on the mid-height canopy, their narrow snouts expertly selectively feeding on the vegetation. You watched as one adult, perhaps 10 tonnes of muscle and bone, lifted its head, its tail swishing gently. The sound of them tearing leaves was like a rhythmic rustling in a windstorm.