Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758 Pygostylia Chatterjee 1997 [Chiappe 2001] Ornithothoraces Chiappe 1995 Subclass Ornithuromorpha Chiappe, 2002 see Clade Ornithuromorpha Chiappe 2001 Genus †Yanornis Zhou & Zhang, 2001