From a 20-Foot Poop Pile, Scientists Uncover the Secrets of Giant Sloths

Sloths may seem like quirky tree-dwellers today, but their past reveals a dynasty of giants that once roamed the Americas. Most people know sloths as slow-moving, bear-like creatures that dangle from trees, take nearly a month to digest a single meal, and defecate only once a week. Their closest relatives are anteaters and armadillos, which [...]