Paleotocas are huge, long tunnels dug up by giant animals some 10,000 years ago. This shows how creatures during that age live. These caves are fast becoming popular after a lot of them were seen in Brazil, where a new one was discovered.

Heinrich Frank and Amilcar Adamy are two of the leading paleontologists who have rediscovered these paleotocas, IFL Science reported. After they have rediscovered these giant holes in the last decades, more studies are now dedicated to understanding and explaining this amazing animal engineering. Paleontologists usually study fossil vertebrates, but these holes allow them to learn how these extinct species actually lived, said Professor Frank.

Some paleotocas only have one tunnel, while others have up to 25. These tunnels are usually filled with sediment. Some 50 of these tunnels are big and stable enough for exploration.

According to researchers, these tunnels have sizes that range from 0.8 meters up to as big as 2 meters in diameter. These tunnels extend to as long as 60 meters. Some 2,000 burrows have already been discovered so far.

Scientists claim that these tunnels were dug 8,000 to 10,000 years ago. These scientists believe that the tunnels have usable organic materials and mineral deposits. These tunnels are believed to be dug by colossal, extinct ground sloths, Discover Magazine reported.

Examples of these giant sloths were the Scelerodotherhium and the Glossotherium, which are prehistoric animals that are very common in the Americas. They lived during the Pliocene to the late Pleistocene period.

Other than prehistoric sloths, these tunnels could also have been dug by giant armadillos. When these Paleotocas were dug thousands of years ago, the Amazon used to have a very different topography.

About 10,000 years ago, that region was a Savannah filled with giant alligators, giant mastodons, and these giant diggers. These tunnels are all over South America, with the first one discovered in Argentina back in the 1920s.