[Avialae] Gauthier 1986
   Aves Linnaeus 1758 [Gauthier 1986], nom. cl. inval. see Subclass Aves Linnaeus, 1758
     Pygostylia Chatterjee 1997 [Chiappe 2001]
       1 †Confuciusornithidae Hou, Zhou, Gu & Zhang 1995 [Chiappe et al. 1999] see Family Confuciusornithidae Hou, Zhou, Gu & Zhang, 1995
       2 Ornithothoraces Chiappe 1995