Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
Count: †15o;15f;23g;26s
   Subclass Ornithurae Haeckel, 1866 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991}
  Count: †5o;5f;6g;6s
     Order †Yixianornithiformes Zhou & Zhang, 2006
    Count: [†*] †1f;1g;1s
       1 Family †Yixianornithidae Zhou & Zhang, 2006
      Count: [†*] †1g;1s