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

The Utah sun was oppressive, making the air shimmer above the rust-red rock. you were tracing a dry creek bed, looking for bone fragments, when a low, shrill chirping stopped me cold. It wasn't a bird—too rhythmic, too reptilian.

You froze against a juniper bush. About twenty yards away, at the edge of the shade, a small meat-eating dinosaur stepped into the open. It was a Tanycolagreus.

It was roughly the size of a modern Labrador retriever, maybe slightly larger, with a long, elegant neck and a tail held perfectly straight for balance. Its skin was mottled grey-green, blending perfectly with the arid scrub. It was remarkably graceful, its slender legs moving with lightning speed as it hunted.

It stopped, looking directly at your position with intelligent, avian eyes, its head tilted. You could barely breathe as the carnivore assess you, if you are a meal…