Ornithostoma

''Ornithostoma'' (meaning "bird mouth") is a genus of pterodactyloid pterosaur that lived during the Early Cretaceous period (Albian stage) of Europe, around 110 million years ago. ''Ornithostoma'' was once thought to have been a senior synonym of the pteranodontid ''Pteranodon'' due to its toothless anatomy and prior naming.

History

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 (who considered the later holotype jaw fragment part of a metacarpal) 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.Williston, S.W., 1893, "Kansas pterodactyls, Part II", ''Kansas University Quarterly'', 2: 97-81 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''.

The holotype specimen is a snout fragment with a length of about five centimetres or two inches. It represents a triangular cross-section of the snout, about an inch high. There is no crest and the jaws are toothless but featuring low protruding rims. The fragment is tapering towards the front, the upper edge inclining under an angle of 12°, indicating the snout tip was located about ten centimetres to the front of the breakage forming the anterior edge of the fragment.

In 1914, Reginald Walter Hooley reviewed the material. He, incorrectly, claimed the pelvis elements were misidentified parts of the notarium of the shoulder girdle and referred several additional specimens to ''Ornithostoma'', among them a skull fragment featuring a crest base, specimen CAMSM B.54406, and postcranial fragments such as vertebrae and limbs.

In a 1994 paper, S. Christopher Bennett like Lydekker considered ''Ornithostoma'' to be distinct from ''Pteranodon'', mainly because of the lower edge ridges of the jaw. He also concluded that it was a ''nomen dubium''. This in 2001 was rejected however, by David Unwin who thought ''Ornithostoma'' to be a valid genus belonging to the Pteranodontidae, but limited the referable material to the original three fragments, including perhaps CAMSM B.54406. Hooley's postcranial fragments he referred to ''Lonchodectes''. In 2012, Alexander O. Averianov again recombined the holotype with CAMSM B.54406 and selected postcrania, the combination showing traits that indicated a position in the Azhdarchoidea, representing an animal similar in some ways to '' Tapejara''.Averianov, A.O. (2012). "''Ornithostoma sedgwicki'' – valid taxon of azhdarchoid pterosaurs." ''Proceedings of the Zoological Institute RAS'', 316(1): 40–49.

There has also been an ''Ornithostoma'' species based on a find from Russia. In 1914 Nikolai Nikolaevich Bogolubov named a single large vertebra found near Petrovsk ''Ornithostoma orientalis''.Bogolubov, N.N., 1914, "O pozvonk’ pterodaktilya uz’ vyerkhnyem’lovyikh’ otlozhyenii Saratovskoi gubyernii", ''Ezhegodnik po Geologii i Mineralogii Rossii'', 16: 1–7 The name was emended to ''O. orientale'' by George Olshevsky in 1991 because ''stoma'' is neuter. It has been renamed ''Bogolubovia orientalis'' (Nesov & Yarkov 1989) and been transferred from the Pteranodontidae to the Azhdarchidae.

In 2020, Roy E. Smith and colleagues restricted ''Ornithostoma'' to include only jaw fragments, and considered it an azhdarchoid.

See also

* List of pterosaur genera
* Timeline of pterosaur research

References

Pterosauria Translation & Pronunciation Guide

{{Portalbar, Paleontology, Cretaceous, United Kingdom

Azhdarchoids
Early Cretaceous pterosaurs of Europe
Taxa named by Harry Seeley
Fossil taxa described in 1871
Albian life