Today, sloths are slow-moving, tree-dwelling creatures that live in Central and South America and can grow up to 2.5 feet long. Thousands of years ago, however, some sloths walked along the ground, ...

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 ...

Most people are familiar with modern sloths — slow-moving, tree-dwelling mammals that digest food slowly and descend only occasionally. Their closest living relatives are anteaters and armadillos, a ...