Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Order Primates Linnaeus, 1758 - primates
       Suborder Strepsirrhini Geoffroy Saint-Hilaire, 1812
         Infraorder Lemuriformes Gregory, 1915
           Superfamily Lemuroidea Gray, 1821
             Family Indriidae Burnett, 1828, orth. cons. - avahi, sifakas, and indri
               Genus Propithecus Bennett, 1832 - sifakas
                 Propithecus diadema Bennett, 1832 - diadem sifaka
                   1 [Propithecus diadema diadema]ᵀ Bennett, 1832
                   2 Propithecus diadema candidus Grandidier, 1871