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] Pelecaniformes Sharpe, 1891
         ?Family Phaethontidae Brandt, 1831 [monotypic] - tropicbirds
           Genus Phaethon Linnaeus, 1758
             Phaethon aethereus Linnaeus, 1758 - red-billed tropicbird
               1 Phaethon aethereus mesonauta Peters, 1930
               2 Phaethon aethereus aethereus Linnaeus, 1758
               3 Phaethon aethereus indicus Hume, 1876