The bony-toothed or pseudotooth birds were initially believed to be related to albatrosses in the Procellariiformes, but actually they seem to be rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty. Also, their internal taxonomy is not well-resolved. An earlier-described pseudotooth bird, Cyphornis magnus from Vancouver Island (Canada), was believed to be of Eocene age but is nowadays assumed to have lived in the Early Miocene, not too long before the Clarendonian (Middle/Late Miocene) O. orri. It may be that Osteodontornis is a junior synonym of Cyphornis