As the meat it ate came in bigger and bigger packages, an ancient predator found a solution — it evolved serrated teeth similar to steak knives, a Canadian study has found. Dimetrodon was a ...

Paleontologists have long been fascinated by bizarre structures on prehistoric animals. The horns of Styracosaurus, the sail of Dimetrodon, the crest of Tupuxuara and more—these odd ornaments raise ...

DENVER — Talk about a creature feature: A bizarre boomerang-headed amphibian that burrowed in a seasonal pond in what is now Texas often met its doom in the jaws of a reptilian fin-backed mammalian ...