Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
   Pygostylia Chatterjee 1997 [Chiappe 2001]
     1 [Family] †Confuciusornithidae Hou, Zhou, Gu & Zhang, 1995
     2.1 Genus †Sapeornis Zhou & Zhang, 2002
     2.2 Ornithothoraces Chiappe 1995