Mylodontidae is a family of extinct mammals within the order of Pilosa and suborder Folivora living from approximately 23 mya—11,000 years ago, existing for approximately 22.89 million years. This family of ground sloths is related to the other families of extinct ground sloths, being the Megatheriidae, the Nothrotheriidae, the Orophodontidae and the Scelidotheriidae. The only extant families of the suborder Folivora are the Bradypodidae and the Megalonychidae. Phylogenetic analyses using homologous sequences from all extant edentate groups indicates that the Mylodontidae were closer related to Megalonychidae than to Bradypodidae.

The mylodontids together with their relatives the scelidotheriids and the orophodontids form the Mylodonta, the second radiation of ground sloths. The discovery of their fossils in caverns associated with human occupation lead some early researchers to theorize that the early humans built corrals when they could procure a young ground sloth, to raise the animal to butchering size. However, radiocarbon dates do not support simultaneous occupation of the site by humans and sloths. Subfossil remains like coproliths, fur and skin have been discovered in some quantities.


  • Urumacotherium (incertae sedis)
  • Pseudoprepotherium
  • Mirandabradys
  • Subfamily Lestodontinae
  • Bolivartherium
    • Tribe Thinobadistini
      • Genus Thinobadistes
      • Genus Sphenotherus
    • Tribe Glossotheriini
      • Genus Acremylodon
      • Genus Ranculcus
      • Genus Glossotherium
      • Genus Paramylodon
      • Genus Mylodonopsis
    • Tribe Lestodontini
      • Genus Lestodon
      • Genus Lestodontidion
  • Subfamily Mylodontinae
    • Genus Glossotheriopsis
    • Genus Promylodon
    • Genus Strabsodon
    • Genus Megabradys
    • Genus Pleurolestodon
    • Genus Mylodon