Researchers in Costa Rica have uncovered ancient mastodon and giant sloth fossils, shedding light on the prehistoric giants that once roamed the region.

Sometimes it nice to just kick back and take it slow. Really slow. So what if evolution had the same mindset, and decided to take its time before getting rid of some prehistoric creatures? What if the ...

Researchers in Costa Rica have unearthed fossils from a mastodon and a giant sloth that lived as many as 40,000 years ago, officials announced Friday, calling it the biggest such find here in decades.

SAN JOSE, Costa Rica — Researchers in Costa Rica have unearthed fossils from a mastodon and a giant sloth that lived as many as 40,000 years ago, officials announced Friday, calling it the biggest ...

Costa Rica's Museo Nacional announces a groundbreaking fossil discovery in Cartago, including remains of a mastodon-like ...

Long before today’s tree-dwelling sloths, a 4-ton giant roamed South America — and it may have stood and fought like a bear.

While sharks may have emerged before trees, it’s the latter that holds the title of the longest-living organisms. The oldest-known, still-living, individual tree is a 4,857-year-old Californian ...