Brazilian paleoburrows?

Aliens, secret military operations or megafauna?

Adam Hennessy


Something a little different today, but something I found really intriguing.

We will be delving (pun intended) into the underground ‘tunnels’ in Brazil that have been found winding beneath the Amazon.

What are they?

I parenthesised the word ‘tunnel’ as while colloquially correct the actual term given to these structures is paleoburrow.

Defined a paleoburrow is an

“burrow formed by an animal of the ancient past.”[1]

Wikipedia goes a little deeper and a better functional definition is that a paleoburrow is

“an underground shelter (tunnel, burrow, lair, etc.) excavated by extinct paleo-vertebrate megafauna (i.e., giant mammals, such as ground sloths) that lived in the prehistoric era.”[2]

Generally, these burrows are small (large compared to their modern equivalent, but nonetheless overall quite small. However, what brings us here today is a particular system of tunnels discovered by Amilcar Adamy a geologist working for Brazilian Geological Survey (known as CPRM [its Portuguese initialisation]) in 2010 and explored in 2015.

Credit: Amilcar Adamy/CPRM

This burrow system is massive.

It has a main entrance with branching tunnels totalling around 2,000 feet in length. The main shaft (pictured above) is larger today than it was when dug, due to erosion, but even at the time best estimates place it at over 6 feet 3–5 feet wide. This equates to about 4,000 metric tons of dirt and rock that was excavated to create the burrow.

4,000 metric tons is 4 million kilograms or 8,818,490 pounds.

Credit: Amilcar Adamy/CPRM

Where are they?

The large site mentioned above is beneath the Amazon in Brazil in a place called Rondonia, a few miles north of the Bolivian border.