Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Class Mammalia Linnaeus, 1758 - mammals
       Order Edentata Vicq-d'Azyr, 1792 see Order Xenarthra Cope, 1889
         Family Megalonychidae Gervais, 1855 - West Indian sloths and two-toed tree sloths