On Wednesday, the Santa Cruz Museum of Natural History announced that it's now in possession of a prehistoric left arm bone belonging to a Jefferson’s ground sloth (Megalonyx jeffersonii ...

Dire wolves — or really, wolves with traits like the extinct species — are back. But New York has plenty of its own fascinating extinct species.

Their discovery turned out to be a prehistoric left arm bone of an ancient Jefferson's ground sloth (known as Megalonyx jeffersonii). The fossil is believed to be between 11,500 and 300,000 years old.

Why not bring back its 8-foot-tall relative? Jefferson’s ground sloth: Yes, it's named after the former U.S. president. And it stood around 10 feet tall. Passenger pigeon: Once found across ...

Snowmass, Colorado, is the site of an incredible discovery of prehistoric mammal bones. Travelers can hike the beauty of this ...