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

The water of the Western Interior Seaway is deceptively calm today, a warm, bright blue expanse that masks the nightmare lurking just below the surface. You were hovering near a small, rocky outcrop, observing a small flock of Hesperornis—those strange, wingless, penguin-like birds that dominate these waters. They are diving, their streamlined bodies acting like torpedoes, seeking schools of fish.

Suddenly, you notice that the water 20 meters away bulges. Several massive, bullet-like shapes, varying up to 20 feet long, cruise in the depths of the surface. You catch a glimpse of their silvery bellies and dark backs that camouflage these shapes perfectly against the changing light of the depth.

The Hesperornis flock in the waters try to dive, but its specialized hind legs cannot match the sheer acceleration of the new arrivals that suddenly propel forward, faster than almost anything in this shallow sea.

The air rips with the sound of a violent splash, and you soon spot a gaping, upturned jaw lined with dagger-like teeth, submerging from the surface, wide open and swallowing one of the birds whole in front of your very eyes. These belong to a Xiphactinus, known for its voracious appetite. The predatory fish continues its momentum and disappears underwater, leaving only a cloud of bubbles and a faint tremor in the water.

The water is quiet again, but the Xiphactinus pod is still there, cruising just beneath you —stranded on this rocky outcrop— and already searching for their next meal…