Fans of the movie franchise Zootopia know that sloths make the perfect DMV (Department of Mammal Vehicles) workers.

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

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.

Sloth selfie bans are spreading because cute photos hide stress, disease risk, and illegal wildlife trade most tourists never ...

Scientists have analyzed ancient DNA and compared more than 400 fossils from 17 natural history museums to figure out how and why extinct sloths got so big. Most of us are familiar sloths, the ...

Defecating exposes sloths to predators on the jungle floor. An unexpected ally benefits, and returns the favor. A brown-throated three-toed sloth peers over a tree's buttress root while defecating on ...