
Sloths once came in a dizzying array of sizes. Here’s why
The sloth family tree once sported a dizzying array of branches, body sizes and lifestyles, from small and limber tree climbers to lumbering bear-sized landlubbers. Why sloth body size was once so diverse, while today’s sloths are limited to just two diminutive tree-dwellers, has been a long-standing question. Scientists have proposed that sloths’ body size…