Neornithes Gadow, 1893 - living birds
   Neognathae Pycraft 1900 see Cohort Neognathae Pycraft, 1900
     Neoaves Sibley et al. 1988 see Subcohort Neoaves Sibley et al., 1988
       [Order] Strigiformes Wagler, 1830 - owls
         Family Strigidae Vigors, 1825 - owls
           Subfamily Asioninae
             Genus Asio Brisson, 1760
               Asio stygius (Wagler, 1832) - stygian owl
                 1 Asio stygius lambi Moore, 1937
                 2 Asio stygius robustus Kelso, 1934
                 3 Asio stygius siguapa (d'Orbigny, 1839)
                 4 Asio stygius noctipetens Riley, 1916
                 5 Asio stygius stygius (Wagler, 1832)
                 6 Asio stygius barberoi Bertoni, 1930