Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
   Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
     Infraclass Neoaves Sibley et al., 1988 see Subcohort Neoaves Sibley et al., 1988
       Parvclass Coraciae see Order Coraciiformes Forbes, 1884
         Superorder Bucerotimorphae see Suborder Bucerotes Fürbringer, 1888
           Order Bucerotiformes Fürbringer, 1888 see Infraorder Bucerotides Fürbringer, 1888
             Family Bucerotidae Vigors - hornbills
               Genus Aceros Hodgson, 1844
                 01 Aceros comatus (Raffles, 1822) - white-crowned hornbill see Berenicornis comatus (Raffles, 1822)
                 02 Aceros nipalensis (Hodgson, 1829) - rufous-necked hornbill
                 03 Aceros corrugatus (Temminck, 1832) - wrinkled hornbill
                 04 Aceros waldeni (Sharpe, 1877) - writhed-billed hornbill
                 05 Aceros leucocephalus (Vieillot, 1816) - writhed hornbill
                 06 Aceros cassidix (Temminck, 1823) - knobbed hornbill
                 07 Aceros undulatus (Shaw, 1811) - wreathed hornbill see Rhyticeros undulatus (Shaw, 1811)
                 08 Aceros narcondami (Hume, 1873) - Narcondam hornbill see Rhyticeros narcondami Hume, 1873
                 09 Aceros everetti Rothschild, 1897 - Sumba hornbill see Rhyticeros everetti (Rothschild, 1897)
                 10 Aceros subruficollis (Blyth, 1843) - plain-pouched hornbill see Rhyticeros subruficollis (Blyth, 1843)
                 11 Aceros plicatus (Forster, 1781) - Blyth's hornbill see Rhyticeros plicatus (J.R. Forster, 1781)