Mysterious Tunnels Dug by Giant Sloths

Researchers have found massive tunnels in South America that are believed to have been carved out by giant sloths.

For many years these huge tunnels scattered around South America have puzzled scientists over their origins, especially as they are not the result of any known natural geologic process. Now, however, large claw marks have been discovered on the ceilings and walls of the tunnels.

According to a report from Discover Magazine, these tunnels are best described as paleoburrows - underground shelters excavated by extinct paleo-vertebrate megafauna (giant mammals, such as ground sloths) that lived in the prehistoric era. Brazilian geologist Heinrich Frank and his team believe that ground sloths are responsible for the large tunnels, some tunnels measuring up to 2m in diameter.

Ground sloths have been extinct on the mainland of North and South America for 10,000 years or more. And they were nothing like the sloths we see today; they were part of the mammalian superorder Xenarthra, and were enormous. Weighing around 4 tons and about the same size as an African elephant, these hairy creatures were up to 18 feet tall when standing up and had fearsome 12 inch claws which, as it transpires, were well suited to excavating tunnels.

Researchers still aren't sure why they dug these extensive caverns but hope to find an answer to that question at some point in the future.

Photo credit: Heinrich Frank