Amilcar Adamy, a geologist with the Brazilian Geological Survey, in 2010, was the first to investigate rumors of an impressive cave in southern Brazil. He at the time, was working on a general survey of the Amazonian state of Rondonia and after asking around, he eventually found a gaping hole on a wooded slope, which was a few miles north of the Bolivian border. Though he couldn’t study the cave in detail in the first encounter, one thing was known that the mega tunnels were not something that happened naturally, and he resolved to return.
Rise Of The Burrow
Before Adamy, another Brazilian geologist Heinrich Frank, a professor at the Federal University of Rio Grande do Sul, was zipping down the highway on a Friday afternoon, who happened upon a different, equally peculiar cave which was a mega tunnel. Frank returned to this site and crawled inside, and saw a single shaft, about 15 feet long; at its end, while on his back, he found what looked like claw marks all over the ceiling, but because he was not able to identify any geological reason, he concluded that it was dug by an extent sloth species.
Until early 2000s, no burrows were attributed to the extinct megafauna. But, Frank and his students surveyed a 45-mile stretch of highway construction near the city of Porto Alegre, and identified paleoburrows in more than 70 percent of road cuts. Some were filled with sediment while some were open, like the one that first attracted Frank’s attention.
Finding a suitable passage, he entered through an elliptical shaft roughly four-feet wide, 65-feet long and lined with claw marks, which he calculated to be 250 feet long, and he claimed that there is no geological process that can produce such mega tunnels. He has documented some 1,500 paleoburrows so far in Rio Grande do Sul, his home state and also hundreds more in Santa Catarina.
The First Mega Tunnel In The Amazon
Amilcar Adamy of the CPRM, returned to the strange cave in Rondonia, in 2015, turned out to be the first paleoburrow discovered in the Amazon, and turned out to be one of the largest ever measured, with branching tunnels altogether tallying about 2,000 feet in length. Adamy also claimed that it could not have been made naturally and that there were more such tunnels.
In Rio Grande do Sul, Frank found burrows measuring some hundreds of feet, and more than 1,000 total feet of tunnel have been measured in another burrow in the Gandarela Mountains, though Frank’s reports of one burrow more than 3,000 feet long in Santa Catarina are yet to be investigated.
According to Frank, the mega tunnels measuring upto 5 feet in diameter, were dug by ground sloths. He and his colleagues believe that there could be several genera such as Catonyx, Glossotherium and the massive, several-ton Lestodon, that once lived in South America and whose fossil remains suggest adaptation for serious digging, while the others believe that there could be extinct armadillos as well, behind this, but apparently Frank and his colleagues are still trying to explain it.
The giant armadillo largest living member of the family, weighs between 65 and 90 pounds and its burrows are about 16 inches in diameter and up to about 20 feet long, which made Frank wonder what could be behind the biggest tunnel. Dating the sediments found in the burrow would give a few details but not definitely identify when the burrow was dug. Another thing to wonder is the strange geographic distribution of paleoburrows, all majorly in South American region.
A South American Thing
The beautiful armadillo, Dasypus bellus, an extinct creature about twice the size of today’s nine-banded armadillo, was widespread in Pleistocene North America. Their remains were found in the tunnels, but scientists did not think it could be done by Armadillo. Another possibility was it could be found in North America, but no one paid attention.
A lot of questions are attracting the scientists such as who could have created the tunnels, why and when. Apparently, Frank and his colleagues are studying the patterns in all these to understand what kind of animals could have been digging it.