Ornithostoma

Ornithostoma (meaning "bird mouth") is a genus of pterodactyloid pterosaurs.

In 1869, Harry Govier Seeley, cataloguing the fossils of the Sedgwick Museum at Cambridge, referred three snout fragments of toothless pterosaur specimens from the Lower Cretaceous Albian Cambridge Greensand of England to Ornithocheirus simus. These fragments had in 1859 been described by Richard Owen and referred to Pterodactylus sedgwickii and Pterodactylus fittoni. By 1871 Seeley had realised Ornithocheirus simus was a toothed form, different from the fragments. Therefore he provisionally named them as a separate genus Ornithostoma, the name derived from Greek ὄρνις, ornis, "bird", and στόμα, stoma, "mouth". Seeley as yet provided no specific name. In 1891 however, he named the type species Ornithostoma sedgwicki Seeley 1891, apart from the snout fragments also referring to pelvis elements, claiming it was identical to Pteranodon and had priority. On that occasion he also selected a genolectotype from the three fragments, the holotype of the type species: specimen CAMSM B.54485.

Samuel Wendell Williston in 1893 independently also considered Ornithostoma a synonym of Pteranodon ingens. He therefore renamed Pteranodon species: Ornithostoma ingens (Marsh 1872) Williston 1893 = Pteranodon ingens (= P. longiceps) and Ornithostoma harpyia (Cope 1872) = P. longiceps. Williston also created a special family and subfamily for Ornithostoma: the Ornithostomatidae and the Ornithostomatinae. Today, these concepts are no longer used. Williston indicated O. ingens as the type species, not knowing one had already been designated. However, Richard Lydekker denied the identity in 1904 and, also unaware of Seeley's earlier species name, created a purported (third) type species O. seeleyi.