Ancient sloths lived in trees, on mountains, in deserts, boreal forests and open savannahs. These differences in habitat are primarily what drove the wide difference in size between sloth species. But ...

Imagine a sloth. You probably picture a medium-sized, tree-dwelling creature hanging from a branch. Today's sloths—commonly featured on children's backpacks, stationery and lunch boxes—are slow-moving ...

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.) Imagine a sloth. You probably picture a medium-size, tree-dwelling creature hanging ...