You are in the coastal shorelines of North America, 85 million years ago.

The air over the Western Interior Seaway was thick and unnaturally quiet. Dozens of Geosternbergia—their crests angled into the wind—soared in loose, synchronized formation, feeding on schools of small fish churned to the surface by the rising pressure.

You watched from the safety of a rocky outcrop as a male, identifiable by his massive three-foot crest, dove gracefully, his long beak slicing the water’s surface to snatch a shimmering fish. The flock was a spectacle of collective motion, relying on sharp eyesight to spot prey while their 7-meter wingspans caught the warm thermals.