Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
   Order Struthioniformes Latham, 1790
     1 Suborder Struthiones see Suborder Struthioni
     2 Suborder Rheae Forbes, 1884
     3 Suborder Casuarii see Order Casuariiformes Sclater, 1880
     4 Suborder Apteryges see Order Apterygiformes Haeckel, 1866