Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758 Subclass †Sauriurae Haeckel, 1866 see Subclass Archaeornithes Gadow, 1893 Infraclass †Enantiornithes Walker, 1981 1 Order †Euornithiformes Kurochkin, 1996 [monotypic] 2 Order †Alexornithiformes Brodkorb, 1976