Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758 Subclass Ornithurae Haeckel, 1866 see Clade Ornithurae Haeckel 1866 [Gauthier 1986] {Chiappe 1991} Order †Yixianornithiformes Zhou & Zhang, 2006 Family †Yixianornithidae Zhou & Zhang, 2006 Genus †Yixianornis Zhou & Zhang, 2001 1 †Yixianornis grabaui Zhou & Zhang, 2001