A strange cast of ferocious predators and giant herbivores lived here ... the ice age 20,000 years ago. In prehistoric North America, the short-faced bear (Arctodus simus) ruled the land.

When global temperatures took a nosedive during the Pliocene epoch, this warm-water-loving giant ... prehistoric powerhouse made modern grizzlies look like teddy bears at a picnic. This ancient ...

During the Ice Age, massive woolly mammoths, cave bears, and dire wolves roamed ... time when massive woolly beasts roamed icy plains, giant predators stalked frozen forests, and some creatures ...