Class [Mammalia] Linnaeus, 1758 - mammals
   Order Xenarthra Cope, 1889 - xenarthrans see Magnorder Xenarthra Cope, 1889
     Suborder Pilosa Flower, 1883 - sloths see Order Pilosa Flower, 1883
       Infraorder Phyllophaga Owen, 1842 see Suborder Folivora Delsuc, Catzeflis, Stanhope & Douzery, 2001
         Parvorder Megatheria McKenna & Bell, 1997 see Infraorder Megatheria McKenna & Bell, 1997
           1.1 Family †Megatheriidae Gray, 1821
           1.2 Family ‡Nothrotheriidae Ameghino, 1920 see Tribe Nothrotheriini Ameghino, 1920
           2 Family Megalonychidae Gervais, 1855 - West Indian sloths and two-toed tree sloths