"Brazil’s mysterious tunnels, known as paleoburrows, are massive underground structures found predominantly in the southern and southeastern regions of the country. These fascinating formations are believed to have been dug thousands of years ago by extinct giant ground sloths, some of which were the size of modern-day elephants.

Professor Heinrich Frank, a geologist from the Federal University of Rio Grande do Sul, first encountered these tunnels during an expedition and was immediately struck by their sheer scale and the distinct claw marks etched into their walls, undeniable evidence of ancient megafauna activity. Frank’s research revealed that some of these tunnels stretch over 600 meters, with diameters wide enough to walk through.

He suggests that these burrows were likely created as shelters or protective spaces, though their exact purpose remains a mystery. Frank’s expeditions have also shed light on how these extinct creatures shaped their environment, showcasing their engineering capabilities. These paleoburrows provide a unique window into prehistoric ecosystems and underscore the significant role these massive creatures played in altering their habitats"