Mammaliaformes Rowe 1988
   [crown] Class Mammalia Linnaeus, 1758 - mammals
     Subclass Theriiformes Rowe, 1988 see Division Theriiformes Rowe, 1988
       Infraclass Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg, 1995 see Clade Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg 1995
         Superlegion Trechnotheria McKenna, 1975 see Clade Trechnotheria McKenna 1975
           Legion Cladotheria McKenna, 1975 see Clade Cladotheria McKenna 1975
             Sublegion Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975
               Infralegion Tribosphenida McKenna, 1975 see Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001
                 [crown] Supercohort Theria Parker & Haswell, 1897 - therians see Subclass Theria Parker & Haswell, 1897
                   Cohort Placentalia Owen, 1837 - placentals
                     Magnorder Xenarthra Cope, 1889 - xenarthrans see Superorder Xenarthra Cope, 1889
                       Order Pilosa Flower, 1883 - sloths
                         Suborder Phyllophaga Owen, 1842 see Suborder Folivora Delsuc, Catzeflis, Stanhope & Douzery, 2001
                           Infraorder Megatheria McKenna & Bell, 1997
                             Superfamily Megatherioidea Gray, 1821
                               Family Megalonychidae Gervais, 1855 - West Indian sloths and two-toed tree sloths
                                 Subfamily Megalonychinae Gervais, 1855
                                   Tribe Choloepodini Gray, 1871
                                     Subtribe ‡Acratocnina Varona, 1974
                                       Genus †Acratocnus Anthony, 1916 - Puerto Rican ground sloth