Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Order Primates Linnaeus, 1758 - primates
       Suborder Haplorrhini Pocock, 1918 see Suborder Haplorhini Pocock, 1918
         Infraorder Simiiformes Haeckel, 1866
           Parvorder Catarrhini Geoffroy Saint-Hilaire, 1812
             Superfamily Cercopithecoidea Gray, 1821
               Family Cercopithecidae Gray, 1821 - Old World monkeys
                 Subfamily Cercopithecinae Gray, 1821
                   Genus Mandrillus Ritgen, 1824 - forest baboons
                     Mandrillus leucophaeus (F. Cuvier, 1807) - drill
                       Mandrillus leucophaeus poensis Zukowsky, 1922