The jungle of the Yucatán in Mexico is not typically known as a great place to find fossils. The humid environment has destroyed most traces of bone of the animals that lived here over thousands of years, but there is one place where they remain less disturbed—in caves.

After diving 100 feet underground in a limestone cave in 2009, underwater cave explorer Vicente Fito came upon an incredibly well-preserved fossil sloth. It was recently confirmed as previously unknown to science. Fito deposited the bones with the National Institute of Anthropology and History in Mexico and they were recently pieced together and described.

The new species of sloth, called Xibalbaonyx oviceps, is represented by a nearly flawless skull and many other bones.