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+--- Thread: Article Ancient tunnels built thousands of years ago weren't made by humans (/thread-20540.html)
Ancient tunnels built thousands of years ago weren't made by humans - C C - May 29, 2026
https://www.indy100.com/science-tech/ancient-tunnels-south-america-scientists-discovered-2676938057
EXCERPTS: Huge ancient underground tunnels have been discovered in Brazil and Argentina, and the source of these huge structures is not believed to be due to humans or natural geological processes.
Reaching over 600 meters in length and 1.8 meters in height, over 1,500 of this type of tunnel have been found in the Rio Grande do Sul region in southern Brazil and were initially located by geology professor Heinrich Frank.
Given the sheer size of the burrows, it's not down to humans or the environment - so what is believed to be the cause? The primary theory cited in a 2018 study published in Science Advances is that giant extinct ground sloths are responsible for building these tunnels that typically have distinct features, such as big claw scratches, with a parallel layout - something Frank points out.
“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,” Frank explained to Discover.
The professor noted he has “seen dozens of caves that have inorganic origins, and in these cases, it’s very clear that digging animals had no role in their creation.”
Natural environmental processes like erosion can be ruled out due to the scope, details and geometry of the tunnels. With the fingers pointing to giant extinct ground sloths - what do we know about these prehistoric creatures?
[...] As the number of paleoburrows being discovered continues to rise across South America, understanding the ecological role is the next step researchers are seeking to understand the purpose of the tunnels and their impact on the surrounding environment... (MORE - missing details)
At the 3:17 minute mark .... https://youtu.be/419j-lI_znM