Though it may sound outlandish, it’s actually what one finds across southern Brazil.

Known as paleoburrows, these enormous tunnels can measure up to 2,000 feet long and over six feet tall.

A few weeks later he made his way back and entered the hole.

Paleoburrow in Brazil

Photo: Amilcar Adamy/CPRM

Crawling down the 15-foot-long opening, he noticed claw marks across the ceiling of the cave.

Given his expertise, he knew that no natural phenomenon would create a cave with those characteristics.

So what is a paleoburrow?

Artist Rendering of Giant Ground Sloth

Artist rendering of giant ground sloth (Photo:Robert Bruce Horsfall)

By using Google and examining photos people post, he’s been able to document over1,500 paleoburrows.

But, now that these areas have been discovered, researchers are in a race against time.

As construction goes upwhether it’s residential buildings or highwaysthere’s a great risk of losing these sites.

Researchers from Projeto Paleotocas Inside a Paleoburrow

Photo: Projeto Paleotocas

This is so important because you’ve got the option to reconstruct the home of a prehistoric animal.

This research doesnt exist in any branch of paleontology.

You have the dinosaurs.

You have their bones.

But you dont know where they lived.

We find their home, Franksaid.

Our group is on the new frontier in this area.

And we wish there were others working with us.

Southern Brazil is filled with enormous underground tunnels called paleoburrows.