Huge Tunnels Found In Brazil Are Thought To Have Been Dug By Long-Extinct Mega-Sloths

Image: IBGS Research Group, Stephen Hasiotis

In Brazil, just north of the border with Bolivia, you might stumble across some enormous caves. Yet while they’re big enough for a man to stand upright in them, they weren’t created by any geological process. And scientists now think they’ve discovered exactly what it was that carved these incredible holes into the ground.