For nearly 30 million years, a 2,000-pound beast known as the entelodont ruled a sweeping empire from Mongolia to what is now ...

Here are just a few groups of ancient animals that live on: And, here are the animals that get my vote for “most prehistoric-looking ... 60 million years. Only two species survive today.

Pachycephalosaurus wyomingensis was the largest of the pachycephalosaurids—"thick-headed dinosaurs"—which ... Pachycephalosaurus's padded skull allowed these animals to engage in head-butting ...