SAO PAULO — Sloths weren't always slow-moving, furry tree-dwellers. Their prehistoric ancestors were huge — up to 4 tons (3.6 metric tons) — and when startled, they brandished immense claws.

Today's avocado industry, a multi-billion-dollar global enterprise, relies primarily on a single variety: the Hass avocado.

Prehistoric fossils dating back to the Ice Age discovered in South Louisiana. What prehistoric animals used to roam Louisiana ...

For example, water levels rose more than 300 feet at the end of the Ice Age, flooding the cave system and preserving the remains of extinct megafauna. Humans likely didn't live in the caves, but ...

Sloth digestive system. Image via Unsplash Sloths are the only mammals designed to spend most of their lives hanging upside down. Their internal organs are attached to their ribcage rather than ...

Marine megafauna, including whales and sharks, face increasing threats from human activities, impacting ocean ecosystems. A recent study by WHOI and ANU tracked these species to identify critical ...

Long before they were nature’s slowpokes, sloths were megafauna monsters — towering creatures capable of defending themselves and changing landscapes. This is the story of how evolution nerfed ...

Defecating exposes sloths to predators on the jungle floor. An unexpected ally benefits, and returns the favor. A brown-throated three-toed sloth peers over a tree's buttress root while defecating ...

New research I led sought to shed light on the issue. My colleagues and I gathered 30 years of satellite tracking data to map hotspots of megafauna activity around the globe. We tracked 12,794 animals ...

From detailed depictions of megafauna like giant sloths to the daily lives of early inhabitants, these ochre paintings provide invaluable insight into prehistoric life and biodiversity.

Global tracking of marine megafauna space use reveals how to achieve conservation targets. Science, 2025; 388 (6751): 1086 DOI: 10.1126/science.adl0239 ...