Odontornithes is an obsolete taxonomic term proposed by American paleontologist Othniel Charles Marsh for birds possessing teeth, notably the genera Hesperornis and Ichthyornis from the Cretaceous deposits of Kansas. In 1875 he divided this "subclass" into Odontolcae, with the teeth standing in grooves, and Odontotormae, with the teeth in separate alveoles or sockets. In his 1880 work, Odontornithes: A monograph on the extinct toothed birds of North America, he added the Saururae, represented by Archaeopteryx, as a third order.