Osteodontornis is an extinct seabird genus. It contains a single named species, Osteodontornis orri (Orr's Bony-toothed Bird, in literal translation of its scientific name), which was described quite exactly one century after the first species of the Pelagornithidae (Pelagornis miocaenus) was. O. orri was named after then-recently deceased naturalist Ellison Orr. 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.