Mylodontids are a group of extinct ground sloths that lived in South America during the Pleistocene Epoch. These fascinating animals were known for their large size, powerful jaws, and long, curved claws. While the name mylodontid is unique to this group of sloths, there are other words that can be used to describe them. For example, these animals are sometimes referred to as megatheriids, which is another name for ground sloths in general. Other synonyms include giant sloths, ground giant sloths, and mylodontines. However, regardless of the name they are given, mylodontids remain a fascinating and important part of South America's prehistoric past.