Researchers have found that massive caverns, tunnels, and burrows in Brazil were dug by prehistoric giant sloths.
Scientists theorized that either humans or geological processes created these huge caverns, also known as paleoburrows. However, there is strong evidence to suggest that huge animals tunneled through the rocks to create their burrows. The smaller tunnels have a diameter of up to 1.5 meters, while larger tunnels are up to two meters high and four meters wide. These tunnels are up to 100 meters long and branch off to different caverns.
Though scientists agreed that megafauna—large prehistoric animals—existed, they could not find the burrows that these creatures would have created. Scientists looked for a long time, to no avail. It was when a couple of geologists stumbled upon unnatural looking caves that science finally found an answer.
Researchers claim that certain characteristics and features of the burrows suggest the involvement of some megafauna. There were long, parallel gouges that look like claw marks on the walls and ceilings of the burrows. It looked as if two or three claws dug these gouges into the rock. The floors were also smooth. These characteristics aren't consistent with naturally occurring caverns and tunnels.
“There’s no geological process in the world that produces long tunnels with a circular or elliptical cross-section, which branch and rise and fall, with claw marks on the walls,” says Heinrich Frank, a geologist and one of the scientists who discovered some of the tunnels. He has actually discovered over a thousand paleoburrows and is also one of the authors of the paper detailing the large structures.
Giant sloths weren't the only ones to create large burrows, but they probably created the largest ones. Smaller megafauna were likely the ones who created the smaller tunnels.
In 2015, Amilcar Adamy, a geologist with the Brazilian Geological Survey, discovered what may be the largest existing paleoburrow to date. There are branching tunnels that altogether measure about two thousand feet long. The ceilings were also originally about six feet high. Researchers estimate that megafauna must have dug out 4,000 metric tons of dirt and rock to create the tunnels.
Adamy claimed that several generations of giant sloths must have built the entire network of tunnels. However, researchers are still wondering as to why the tunnels and caverns were so huge. They were larger than what the animals needed for protection and shelter. This, among other things, are questions that researchers still need to find answers to.
The age of the tunnels and caverns is also something that needs confirmation. For now, researchers guess that the structures may be about 8,000 to 10,000 years old. The researchers have yet to date sediments or mineral deposits in the structures to determine the true age.
In any case, the findings are certainly fascinating at the least. There were massive creatures like giant sloths who walked the earth and have left traces of their existence. If nothing else, the findings give us an idea of the awesome scale of life in prehistoric times.
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