Pleistocene ground sloths constitute a remarkable and diverse group of xenarthran mammals that thrived across South America during a period of significant climatic and environmental flux. Their fossil ...

Ancient sloths ranged in size from tiny climbers to ground-dwelling giants. Now, researchers report this body size diversity was largely shaped by sloths’ habitats, and that these animals’ precipitous ...

Long before today's tree-dwelling sloths became icons of leisure, their ancestors roamed the ground as colossal herbivores. Some of these prehistoric giants weighed up to five tonnes and towered over ...

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 ...