Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
   Subclass Ornithurae Haeckel, 1866 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991}
     Order †Chaoyangornithiformes Hou, 1997, nom. imperf. see Order Chaoyangiiformes Hou, 1997
       1 Family †Chaoyangornithidae Hou, 1997 see Family Chaoyangiidae Hou, 1997