You are in the forested plains of North America, 66 million years ago.

The Cretaceous sun was low, casting long, menacing shadows across the Hell Creek ferns. You had been sitting motionless behind a fallen sequoia log for nearly an hour, hoping to catch a glimpse of a Triceratops herd. What you got instead was a sudden, low hum against the ground.

It wasn’t a roar—it was a rapid, shuffling drumming.

Suddenly, the fern forest ahead parted. They didn't just walk; they flowed. A flock of nearly twenty Ornithomimus erupted from the treeline. Up close, they were terrifyingly beautiful—roughly seven feet tall, covered in a dusky, mottled-grey plumage that shimmered in the late afternoon light. Their necks were long and sinuous, curving like ostriches, and their large, dark eyes surveyed the landscape with high-strung intelligence.

They were foraging. One of the adults, a male with a particularly vibrant feather crest on his head, stopped not fifteen feet from your hiding spot. You could see the individual feathers of its plumage, hear the soft, bird-like clicking sounds it made to its companions, and watch its toothless, keratinous beak swiftly snap up seeds from a plant.