Although it sounds like a grade-B science fiction movie, fossils show that our ancestors once hunted and fought giant ground sloths. For the first time, scientists have uncovered fossilized footprints ...

A bigfoot-like ground sloth had unwelcome company about 11,000 years ago. No matter which way the giant creature went, ancient humans followed it, stepping in its elongated, kidney-shaped paw prints ...

For the three-toed sloth, a trip to the restroom is no rest at all. It’s a long, slow descent into mortal danger from the safety of home among the upper branches of the forest. For the three-toed ...