New research suggests that humans, new to the Americas, lived alongside giant ground sloths and mastodons for millennia.

Fossils show humans coexisted with giant sloths and mastodons for thousands of years. Evidence includes modified sloth bones ...

In the Mesozoic Era, dinosaurs were the undisputed rulers of the land. The Argentinosaurus, possibly the largest dinosaur ...

At New Mexico's White Sands, researchers have uncovered human footprints dated to between 21,000 and 23,000 years ago, as well as similar-aged tracks of giant mammals. But some archaeologists say ...

At New Mexico's White Sands, researchers have uncovered human footprints dated to between 21,000 and 23,000 years ago, as well as similar-aged tracks of giant mammals. But some archaeologists say ...

At New Mexico's White Sands, researchers have uncovered human footprints dated to between 21,000 and 23,000 years ago, as well as similar-aged tracks of giant mammals. But some archaeologists say ...

Aging gracefully comes naturally to these creatures, which can live for hundreds, and sometimes even thousands, of years ...

At New Mexico's White Sands, researchers have uncovered human footprints dated to between 21,000 and 23,000 years ago, as well as similar-aged tracks of giant mammals. But some archaeologists say ...