For decades, researchers were puzzled by these neat, rounded tunnels found in states like and Santa Catarina . It wasn't until scientists examined the clear claw marks etched into the hard clay and stone that the true builders were identified: giant ground sloths (like the Megatherium ) and potentially giant armadillos .
: The complexity of the branching tunnels suggests that these giant sloths may have worked in groups or used the structures on a rotating basis across generations. 3. Extinction and Discovery
The Echoes of Giants: Brazil’s Prehistoric Subterranean Legacy
