Long before humans walked the Earth, the skies of South America were ruled by a colossal bird. Argentavis magnificens, one of the largest flying birds ever discovered, had a wingspan so wide that it ...

Long before humans arrived, Australia was home to unique dinosaurs and massive megafauna found nowhere else on Earth. Its isolation shaped one of the strangest evolutionary stories in history. This ...

A giant kangaroo that once roamed on four legs through remote forests in the Papua New Guinea Highlands may have survived as recently as 20,000 years ago -- long after large-bodied megafauna on ...

The curious minds at What If investigate what Earth was like during the Cenozoic era, revealing mammalian evolution, climate change, and continental shifts. Person shoots at Border Patrol agent, who ...