The Mylodon darwini was a large mammal that lived in this area between 14,500 and 10,000 years ago. Ancient relative of the modern-day sloth, it moved on all fours, measured about 2 m from head to tail, weighed about a ton, and was covered with long thick fur.

The Mylodon was an herbivore of slow habits, but could be a formidable opponent for predators such as big cats, because of its size, powerful claws, and tiny bones that it had embedded in its skin, which were remnants of an ancient protective shell similar to that of an armadillo.

It is the extinct animal that is present in as most amount of sites excavated in the area.