You are in the oceans of New Zealand, 77 million years ago.

The water of the inland sea was unusually calm, the midday sun piercing down to the limestone seabed. You were paddling your shallow-draft skiff over what you knew to be the ancient Waipara gorge, the water no deeper than four meters here. The air was thick, silent, save for the rhythmic dip of your paddle.

Then, the water changed. The turquoise turned to a deep, bruised violet, and a shadow—long, thin, and impossibly large—passed directly beneath your boat.

It was not moving like a fish. It was moving like a dream.

You stopped paddling, paralyzed, as the shadow turned. The water broke ahead of you, not with a crash, but with a smooth, silent surge. First, the snout appeared, narrow and dark, followed by a neck that seemed to continue forever—six, eight, ten meters of serpentine neck twisting through the air, completely independent of the bulky body still submerged below.

It was a Mauisaurus.

Its skin was dark, almost black, with a texture like a seal, slick and glistening with sea water. It was looking at you. It didn’t have the menacing, predatory leer of a mosasaur; its eye, large and dark, seemed filled with cold curiosity. The neck twisted with alarming agility, its head hovering only a few meters away.

You could see the teeth—sharp, jagged, and interlocking—perfect for grabbing fish, or perhaps, for overturning your little boat...