Within the last decade, the hunt's really been on by paleontologists and geologists to locate as many as possible of the huge, neatly-constructed tunnels located deep in the jungles of South America. About 2,000 of these truly wondrous tunnels have been found, with the majority of them discovered by scientist Heinrich Frank.
The most obvious scientific clue that the impressively made tunnels weren't natural geological formations, but instead were "paleotocas or paleoburrows" dug by prehistoric animals, was the claw marks on all of the tunnel walls. The next step was to pinpoint which animal it was, since all of the scratches in the dirt were made by the same type of creature.
Identifying the animal who made those thousands of incredibly large South American tunnels was a tough job for paleontologists, but identify they did. The extinct megafauna giant sloth, Lestodon, is credited as being the tunnels' creator.
Although many of the Brazilian megafauna-made tunnels became filled in with dirt geologically over time, enough of them are still intact and fully open, which allow for complete scientific exploration. These tunnels are thought to be between 8,000 and 10,000 years old. Talk about an antiquated transportation system!
The tunnel-digging giant ground sloths, when standing on their back legs, were about twice as tall as the average man. The long, large claws on these creatures are definitely one of their most noticeable features.
Looking at the tunnel wall and seeing the claw marks of the extinct giant Lestodon sloth close up, it seems at first glance that these are giant worms or tree roots at first glance. But seeing the marks this close is actually a good indication of just how long and wide their claws really were.
Sloths are plant eaters with slow metabolisms, so despite the size of the giant extinct sloths who ate trees and dug up plants, they didn't need a lot of food. Their bulky tails helped in making them very slow-moving creatures.
Ground sloths are part of the family Xenarthrans. This means they are relatives of both the armadillo and anteater. Well, there is a certain exotic-looking kind of family resemblance between the three of them.
The Lestodon-dug burrows make it pretty easy for scientists to explore as they are more than high enough for even the tallest human. The well-formed structures are also wide enough for two or three people to head into side-by-side.
The main reason for the vast extent of tunnels dug by the Lestadon genus of extinct giant ground sloth could have been this animal's food search as they were herbivores who dug in the ground for food. These tree and plant eaters are thought to have weighed up to four tons!
Another intriguing quality of the Lestodon is they're thought to have had the ability to plan their tunnel digging endeavors. Science reached the conclusion with evidence that many of the tunnels were added onto much later than when they were first dug by the giant sloths.
The largest tunnel scientists found displaying signs of having been started, then left and added to over time by the Lestodon is in the Amazon. Brazilian geologists Amilcar Adamy and Heinrich Frank made explorations in this tunnel and found multi-chambers that created a total length of about 2,000 feet.
Although most of the thousands of Lestodon-created paleoburrows found in South America were of a single chamber, some of them, including the large Amazon tunnel, had multi-chambers. Scientists learned all of the paleoburrows were made by many Lestodon animals over a long period of time. The massive tunnels weren't the short-term work of just a few creatures, that's for sure.