You are in the badlands of North America, 75 million years ago.

The heat in the inland valley was thick, smelling of humid volcanic ash and rotting vegetation, but you hardly noticed. You were standing on the edge of a bustling metropolis—not of humans, but of Maiasaura.

The ground was a chaotic landscape of craters, arranged almost systematically. Even from a distance, you could see hundreds of adults, large-headed herbivores with duck-bills and thick noses, moving purposefully. They weren't just wandering; they were acting with purpose. They were caretakers.

You moved closer, stepping carefully around a patch of ferns, and saw one of the mothers. She was easily 30 feet long, a massive adult, but she was behaving gently, managing the heat of her nest by tending to a pile of decomposing plant matter. She wasn't sitting on her eggs—which would surely crush them—but rather using the warmth of the decaying plants in her nested mound to incubate them.

You crept toward an older nest, one that had already hatched. Inside, wobbly-legged, tiny Maiasaura hatchlings were looking up, chirping at a returning adult. The young ones hadn't left the nest; they were roughly a foot and a half long, with undeveloped legs, making them entirely dependent on their parents for food.

A sudden, booming call echoed from another area of the colony. Realizing you are too close to the nest, you look up just in time to see the adult Maiasaura charging towards you…