Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Infraclass Eutheria Gill, 1872
       Magnorder Atlantogenata Waddell, Cao, Hasegawa & Mindell, 1999
         Superorder Xenarthra Cope, 1889
           Order Pilosa Flower, 1883 - sloths
             Suborder Folivora Delsuc, Catzeflis, Stanhope & Douzery, 2001
               Family Megalonychidae Gervais, 1855 - West Indian sloths and two-toed tree sloths