Ornithocheirus
Ornithocheirus | |
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Holotype of O. simus, CAMSM B54428, and referred specimen CAMSM B54552 (holotype of the junior synonym O. platyrhinus)
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | †Pterosauria |
Suborder: | †Pterodactyloidea |
Family: | †Ornithocheiridae |
Subfamily: | †Ornithocheirinae Seeley, 1870 |
Genus: | †Ornithocheirus Seeley, 1869 |
Type species | |
†Ornithocheirus simus Owen, 1861
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Species | |
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Synonyms | |
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Ornithocheirus (from Ancient Greek "ὄρνις", meaning bird, and "χεῖρ", meaning hand) is a pterosaur genus known from fragmentary fossil remains uncovered from sediments in the United Kingdom and possibly Morocco.[1]
Several species have been referred to the genus, most of which are now considered as dubious species, or members of different genera, and the genus is now often considered to include only the type species, Ornithocheirus simus. Species have been referred to Ornithocheirus from the mid-Cretaceous period of North America, Europe and South America, but O. simus is known only from the United Kingdom, though a specimen referred to O. cf. simus is also known from Morocco.
Because O. simus was originally named based on poorly preserved fossil material, the genus Ornithocheirus has suffered enduring problems of
Fossil remains of Ornithocheirus have been recovered mainly from the
Discovery and naming
During the 19th century, in England many fragmentary pterosaur fossils were found in the Cambridge Greensand, a layer from the early Cretaceous, that had originated as a sandy seabed. Decomposing pterosaur cadavers, floating on the sea surface, had gradually lost individual bones that sank to the bottom of the sea. Water currents then moved the bones around, eroding and polishing them, until they were at last covered by more sand and fossilised. Even the largest of these remains were damaged and difficult to interpret. They had been assigned to the genus Pterodactylus, as was common for any pterosaur species described in the early and middle 19th century.[5]
Young researcher
When Seeley published his conclusions in his 1870 book The Ornithosauria, this provoked a reaction by the leading British paleontologist of his day, Sir Richard Owen. Owen was not an evolutionist and he therefore considered the name Ornithocheirus to be inappropriate; he also thought it was possible to distinguish two main types within the material, based on differences in snout form and tooth position — the best fossils consisted of jaw fragments. In 1874, he created two new genera: Coloborhynchus and Criorhynchus. Coloborhynchus (meaning "maimed beak") which comprised a new type species called Coloborhynchus clavirostris, as well as two other species reassigned from Ornithocheirus: C. sedgwickii and C. cuvieri. Criorhynchus (meaning "ram beak") consisted entirely of former Ornithocheirus species: the type species, Criorhynchus simus, and furthermore such as C. eurygnathus, C. capito, C. platystomus, C. crassidens and C. reedi.[9]
Seeley did not accept Owen's position. In 1881 he designated O. simus the type species of Ornithocheirus and named a new separate species called
In 1914
From the seventies onwards many new pterosaur fossils were found in
As a result, though over forty species have been named in the genus Ornithocheirus over the years, only O. simus is currently considered valid by all pterosaur researchers. The species Tropeognathus mesembrinus, which was named by Peter Wellnhofer in 1987, was assigned to Ornithocheirus by David Unwin in 2003, making Tropeognathus a junior synonym.[18] In 1989 however, Alexander Kellner considered it as an Anhanguera mesembrinus, then as a Coloborhynchus mesembrinus by André Veldmeijer in 1998 and as a Criorhynchus mesembrinus by Michael Fastnacht in 2001.[19] Even earlier, in 2001, Unwin had referred the "Tropeognathus" material to O. simus in which was followed by Veldmeijer; however, Veldmeijer rejected O. simus as the type species in favor of O. compressirostris (alternately Lonchodectes), and he used the names Criorhynchus simus and Criorhynchus mesembrinus instead.[5][20]
Formerly assigned species
In 2013, Rodrigues and Kellner found Ornithocheirus to be monotypic, containing only O. simus, and placed most other species in other genera, or declared them
Misassigned species:
- O. compressirostris (Hooley, 1914) = Pterodactylus compressirostris, Owen, 1851 [now classified as Lonchodectes]
- O. crassidens (Seeley, 1870) = [now classified as Amblydectes]
- O. cuvieri (Seeley, 1870) = Pterodactylus cuvieri, Bowerbank, 1851 [now classified as Cimoliopterus]
- O. curtus (Hooley, 1914) = Pterodactylus curtus, Owen, 1874
- O. giganteus (Owen, 1879) = Pterodactylus giganteus, Bowerbank, 1846 [now classified as Lonchodraco]
- "O." hilsensis (Koken, 1883) = indeterminate Neotheropoda[21]
- O. mesembrinus (Wellnhofer, 1987) = Tropeognathus mesembrinus, Wellnfofer, 1987
- O. nobilis (Owen, 1869) = Pterodactylus nobilis, Owen 1869
- O. sagittirostris (Seeley, 1874) = [now classified as Serradraco]
- O. simus (Owen, 1861) = [originally Pterodactylus] (type)
- O. sedgwicki (Owen, 1859) = Pterodactylus sedgwickii, Owen 1859 [now classified as Aerodraco]
- "O." wiedenrothi (Wild, 1990) = [now classified as Targaryendraco]
Description
The type species, Ornithocheirus simus, is only known from fragmentary jaw tips. It bore a distinctive convex "keeled" crest on its snout similar to its relatives.[19] Ornithocheirus had relatively narrow jaw tips compared to the related Coloborhynchus and Tropeognathus, which had prominently-expanded rosettes of teeth, as well as a more developed "keeled" crest compared to Ornithocheirus. Another feature that made Ornithocheirus unique and unlike its relatives, was that its teeth of were mostly vertical, rather than set at an outward-pointing angle.[19][8]
It was believed in the past that Ornithocheirus was one of the largest pterosaurs to have existed, with a wingspan possibly measuring 40 feet (12.2 m) wide. However, this is a highly exaggerated number, as the animal's wingspan likely measured 15 to 20 feet (4.5 to 6.1 m) wide, which would make it a medium-sized pterosaur. A related species called Tropeognathus had a wingspan measuring about 27 feet (8.2 m) wide, making it the largest toothed pterosaur known.[3][8] In 2022, Gregory S. Paul estimated that Ornithocheirus had a wingspan of 5 m (16 ft) and a body mass of 20 kg (44 lb).[28]
Classification
A topology made by Andres and Myers in 2013 placed Ornithocheirus within the family Ornithocheiridae in a more derived position than Tropeognathus, but in a more basal position than Coloborhynchus, and the family itself is placed within the more inclusive clade Ornithocheirae.[29] In 2019, Pêgas et al. found Ornithocheirus to be in a basal member of the clade Ornithocheirae, reclassifying all other snout-crested pterosaurs in the family Anhangueridae. Their cladogram is shown on the right.[30]
Topology 1: Andres & Myers (2013).[29]
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Topology 2: Pêgas et al. (2019).[30]
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See also
Notes
- Haines, T., and Chambers, P. (2006). The Complete Guide to Prehistoric Life. Canada: Firefly Books Ltd.
References
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- ^ a b Unwin D.M., 2001, "An overview of the pterosaur assemblage from the Cambridge Greensand (Cretaceous) of Eastern England", Mitteilungen aus dem Museum für Naturkunde in Berlin, Geowissenschaftliche Reihe 4: 189–221
- ISSN 0374-5481.
- ^ Seeley, H.G. (1870). "The Ornithosauria: an Elementary Study of the Bones of Pterodactyles". Cambridge: 112–128.
- ^ PMID 23794925.
- ^ Owen, R. 1874, Monograph on the fossil Reptilia of the Mesozoic Formations. Palaeontographical Society, London, 14 pp
- S2CID 219235284.
- ^ Newton, E. T., 1888, "On the Skull, Brain, and Auditory Organ of a new species of Pterosaurian (Scaphognathus purdoni), from the Upper Lias near Whitby, Yorkshire", Philosophical Transactions of the Royal Society of London, v. 179, p. 503-537
- ^ Cope, E. D. (1872). "On two new Ornithosaurians from Kansas". Proceedings of the American Philosophical Society. 12 (88): 420–422.
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- ^ Khozatskii LI, Yur'ev KB. (1964) [Pterosauria]. In: Orlov JA. (Ed.). Osnovy Paleontologii 12 [Amphibians, Reptiles, Birds].Izdatel'stvo Nauka, Moscow: 589-603
- ^ Kuhn O. (1967) Die fossile Wirbeltierklasse Pterosauria. Verlag Oeben, Krailling bei München, 52 pp.
- ^ Wellnhofer P. (1978) Pterosauria. Handbuch der Paläoherpetologie, Teil 19. Gustav Fischer Verlag, Stuttgart and New York, 82 pp.
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- ^ S2CID 128410270.
- ^ Veldmeijer, A.J. (2006). "Toothed pterosaurs from the Santana Formation (Cretaceous; Aptian-Albian) of northeastern Brazil. A reappraisal on the basis of newly described material Archived 2012-03-17 at the Wayback Machine." Tekst. – Proefschrift Universiteit Utrecht.
- ^ "Neotheropoda".
- ^ Martill, D.M. 2010. The early history of pterosaur discovery in Great Britain. In: Moody, R., Bueefetaut, E., Naish, D. & Martill, D.M. (eds) Dinosaurs and other extinct saurians. Geological Society, London, Special Publication, 343, 20–45.
- ^ Averianov, A.O. (2010). "The osteology of Azhdarcho lancicollis Nessov, 1984 (Pterosauria, Azhdarchidae) from the Late Cretaceous of Uzbekistan" (PDF). Proceedings of the Zoological Institute of the Russian Academy of Sciences. 314 (3): 246–317.
- ^ Averianov, A.; Ekrt, B. (2015). "Cretornis hlavaci Frič, 1881 from the Upper Cretaceous of Czech Republic (Pterosauria, Azhdarchoidea)". Cretaceous Research. 55: 164. doi:10.1016/j.cretres.2015.02.011.
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- ^ S2CID 84617119.
- ^ a b Pêgas, R.V., Holgado, B., Leal, M.E.C., 2019. "Targaryendraco wiedenrothi gen. nov. (Pterodactyloidea, Pteranodontoidea, Lanceodontia) and recognition of a new cosmopolitan lineage of Cretaceous toothed pterodactyloids", Historical Biology, 1–15. doi:10.1080/08912963.2019.1690482