Sixty million years ago—the dawn of their Age—Titanoides was the biggest of mammals, about the size of a polar bear. Stout, thick-legged, big-tailed, weighing half a ton, probably a fine ...

Not only can these gentle giants turn their heads and look at you, but they do so with near-human facial expressions and big, imploring eyes. Belugas reach lengths of 11 to 15 feet and can weigh ...

Dolphins live and hunt in large social groups called pods, and they communicate with each other using high-pitched clicks and ...