Of Man and Manta 

The trio of scientists had been ordered to survey the planet's flora, fauna and mineral resources, and from the very beginning of their mission everything they observed led to one startling conclusion—the mysterious world was virtually identical with the Earth of the Paleocene period, 70,000,000 years ago at the very dawn of the age of mammals!

Their names were Cal, Veg and Aquilon, the most resourceful—and rebellious—of Earth's explorers, and with them came four alien companions, the mantas. Strange flying beings, half-animal, half-fungus, the mantas possessed the keenest senses of any creatures in the universe, a gift which immediately saved the mission from complete disaster.

Detecting strong vibrations coming from a great distance, the mantas warned the humans, and Cal realized that it could mean only one thing; an earthquake—one large enough to produce a tidal wave that would totally inundate the small island where they had set up camp.

Veg, the strongest member of the team, constructed a crude sailing raft, and the party put out to sea to escape the doomed island. It was the beginning of an incredible series of adventures which would lead them to discoveries as momentous as they were deadly.