sentences:  At that time the natural entrance was also sealed off at the request of the Hualapai Indians as it was considered a sacred burial place.Near the natural entrance, the skeletal remains of a Paramylodon harlani (Glossotherium harlani) were also found.This giant and extinct ground sloth lived during the Age of Mammals around 11,000 years ago, when the woolly mammoth and saber tooth cat roamed North America.