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 both Europe and South America, but O. simus is known only from the UK. Because O. simus was originally named based on poorly preserved fossil material, the genus Ornithocheirus has suffered enduring problems of zoological nomenclature.
Fossil remains of Ornithocheirus have been recovered mainly from the Cambridge Greensand of England, dating to the beginning of the Albian stage of the early Cretaceous period, about 110 million years ago. Additional fossils from the Santana Formation of Brazil are sometimes classified as species of Ornithocheirus, but have also been placed in their own genera, most notably Tropeognathus.
|Holotype of O. simus, CAMSM B54428, and referred specimen CAMSM B54552 (holotype of the junior synonym O. platyrhinus)|
O. simus is only known from fragmentary jaw tips. It bore a distinctive convex "keeled" crest on its snout. Ornithocheirus had relatively narrow jaw tips compared to Anhanguera and Coloborhynchus, which had prominently-expanded rosettes of teeth. Also unlike related pterosaurs, the teeth of Ornithocheirus were mostly vertical, rather than set at an outward-pointing angle.
It was believed in the past that Ornithocheirus was one of the largest pterosaurs to have existed, with a wingspan possibly measuring 40 feet wide. However, this is a highly exaggerated number, as the animal's wingspan likely measured 15 to 20 feet wide, which would make it a medium-sized pterosaur. A related species called Tropeognathus had a wingspan measuring between 20 to 25 feet wide.
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.
Young researcher Harry Govier Seeley was commissioned to bring order to the pterosaur collection of the Sedgwick Museum in Cambridge. He soon concluded that it was best to create a new genus for the Cambridge Greensand material that he named Ornithocheirus, "bird hand", as he in this period still considered pterosaurs to be the direct ancestors of birds, and assumed the hand of the genus to represent a transitional stage in the evolution towards the bird hand. To distinguish the best pieces in the collection, and partly because they had already been described as species by other scientists, he in 1869 and 1870 each gave them a separate species name: O. simus, O. woodwardi, O. oxyrhinus, O. carteri, O. platyrhinus, O. sedgwickii, O. crassidens, O. capito, O. eurygnathus, O. reedi, O. cuvieri, O. scaphorhynchus, O. brachyrhinus, O. colorhinus, O. dentatus, O. denticulatus, O. enchorhynchus, O. xyphorhynchus, O. fittoni, O. nasutus, O. polyodon, O. compressirostris, O. tenuirostris, O. machaerorhynchus, O. platystomus, O. microdon, O. oweni and O. huxleyi, thus 28 in total. As yet Seeley did not designate a type species.
When Seeley published his conclusions in his 1870 book The Ornithosauria, this provoked a reaction by the leading British paleontologist of his day, 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. He in 1874 created two new genera: Coloborhynchus and Criorhynchus. Coloborhynchus, "maimed beak", comprised a new species, Coloborhynchus clavirostris, the type species, and two species reassigned from Ornithocheirus: C. sedgwickii and C. cuvieri. Criorhynchus, "ram beak", consisted entirely of former Ornithocheirus species: the type species Criorhynchus simus and furthermore C. eurygnathus, C. capito, C. platystomus, C. crassidens and C. reedi.
Seeley did not accept Owen's position. In 1881 he designated O. simus the type species of Ornithocheirus and named a new species O. bunzeli. In 1888 Edward Newton renamed several existing species names into Ornithocheirus, as Ornithocheirus clavirostris, O. daviesii, O. sagittirostris, O. validus, O. giganteus, O. clifti, O. diomedeus, O. nobilis, O. curtus, O. umbrosus, O. harpyia, O. macrorhinus and O. hlavaci.
In 1914 Reginald Walter Hooley made a new attempt to structure the large number of species. Keeping the name Ornithocheirus, he added to it Owen's Criorhynchus, in which however Coloborhynchus was sunk, and to allow for a greater differentiation created two new genera, again based on jaw form: Lonchodectes and Amblydectes. Lonchodectes, "lance biter", comprised L. compressirostris, L. giganteus and L. daviesii. Amblydectes, "blunt biter", consisted of A. platystomus, A. crassidens and A. eurygnathus. However, Hooley's classification was rarely applied later in the century, when it became common to subsume all the poorly preserved and confusing material under the name Ornithocheirus. A Russian-language overview of Pterosauria in 1964 designated P. compressirostris the type species of Ornithocheirus, which was followed by Kuhn (1967) and Wellnhofer (1978), yet those authors were unaware that Seeley (1881) made P. simus the type species of Ornithocheirus.
From the seventies onwards many new pterosaur fossils were found in Brazil in deposits slightly older than the Cambridge Greensand, 110 million years old. Unlike the English material, these new finds included some of the best preserved large pterosaur skeletons and several new genera names were given to them, such as Anhanguera. This situation caused a renewed interest in the Ornithocheirus material and the validity of the several names based on it, for it might be possible that it could by more detailed studies be established that the Brazilian pterosaurs were actually junior synonyms of the European types. Several European researchers concluded that this was indeed the case. Unwin revived Coloborhynchus and Michael Fastnacht Criorhynchus, each author ascribing Brazilian species to these genera. However, in 2000 Unwin stated that Criorhynchus could not be valid. Referring to Seeley's designation of 1881 he considered Ornithocheirus simus, holotype CAMSM B.54428, to be the type species. This also made it possible to revive Lonchodectes, using as type the former O. compressirostris, which then became L. compressirostris.
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. Tropeognathus mesembrinus named by Peter Wellnhofer in 1987 was assigned to Ornithocheirus by David Unwin in 2003 (making Tropeognathus a junior synonym), but as Anhanguera mesembrinus by Alexander Kellner in 1989, Coloborhynchus mesembrinus by André Veldmeijer in 1998 and Criorhynchus mesembrinus by Michael Fastnacht in 2001. Even earlier, in 2001, Unwin had referred the "Tropeognathus" material to O. simus in which he was followed by Veldmeijer; however the latter overlooked the fact that O. simus is the type species in favor of O. compressirostris (alternately Lonchodectes), and used the names Criorhynchus simus and Cr. mesembrinus.
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 nomina dubia. They also considered O. platyrhinus a junior synonym of O. simus.
Cimoliornis diomedeus, Cretornis hlavatschi, and Palaeornis clifti, originally misidentified as birds, were once referred to Ornithocheirus in the past, but recent papers have found them to be distinct; Cimoliornis may be closer to azhdarchoidea, Cretornis is a valid genus of azhdarchid, and Palaeornis was shown to be a lonchodectid in 2009. O. buenzeli (Bunzel 1871, often misspelled and incorrectly attributed as O. bunzeli, Seeley 1881), cited in the past as evidence of Late Cretaceous ornithocheirids, has since been re-identified as a likely azhdarchid as well.
Amblydectes is known from fragments of jaw. It apparently had a jaw flattened towards the tip and triangular in cross-section. It has at times been synonymised with Coloborhynchus, Criorhynchus, Lonchodectes, or Ornithocheirus. A 2013 study found A. crassidens and A. eurygnathus to be nomina dubia, with A. platystomus possibly belonging to a separate, yet unnamed genus.Anhanguera (pterosaur)
Anhanguera (meaning "old devil", Portuguese pronunciation) is a genus of pterodactyloid pterosaur known from the Early Cretaceous (Albian age, 112 Ma) Romualdo Formation of Brazil. This pterosaur is closely related to Ornithocheirus, and belongs in the family Ornithocheiridae within its own subfamily, Anhanguerinae.Anhanguera piscator
Anhanguera piscator (meaning "fishing old devil") is a species of pterosaur known from the Early Cretaceous (Albian age, 112Ma) Santana Formation of Brazil. This pterosaur is closely related to Ornithocheirus, and belongs in the family Ornithocheiridae within its own subfamily, Anhanguerinae. A. piscator has also been classified in the genus Coloborhynchus as Coloborhynchus piscator or as a synonym of Coloborhynchus robustus.Cambridge Greensand
The Cambridge Greensand is a geological formation in England whose strata date back to the Cenomanian stage of the Late Cretaceous. It forms the transitional bed between the Gault Formation and the Chalk Group in the vicinity of Cambridgeshire, and technically forms the lowest member bed of the West Melbury Marly Chalk Formation. The lithology is made out of glauconitic marl, with a concentration of phosphatic nodules and bones at the base. Dinosaur remains are among the fossils that have been recovered from the formation.Camposipterus
Camposipterus is a genus of pterodactyloid pterosaur from the Cretaceous of England.Cimoliopterus
Cimoliopterus is a genus of pterodactyloid pterosaur from the Cretaceous of England, United Kingdom and Texas, United States.The type species, Cimoliopterus cuvieri, was previously considered parts of several different genera depending on author, but received its own genus in 2013.Cimoliornis
Cimoliornis is a pterosaur genus containing the single species Cimoliornis diomedeus, meaning "long-winged bird of the chalk". It is known from a partial metacarpal (lower wing bone) found in late Cretaceous period English Chalk Formation of the UK.The discovery of Cimoliornis remains was first announced in 1840 by Sir Richard Owen. The remains consisted of a single partial wing bone broken into three pieces, which had been acquired by William Cole, 3rd Earl of Enniskillen, and studied by Enniskillen and William Buckland, who both thought the bone came from a species of giant Cretaceous bird similar to an albatross. Owen agreed that it was a bird, and argued that it may either have been from an albatross sized bird (if it was a humerus) or a much larger bird (if it was a radius). On the latter possibility, Owen wrote that a bird of that size would have been reminiscent of the "fabulous Roc of Arabian romance."In 1842, James Scott Bowerbank re-examined the remains and concluded that they actually belonged to a pterosaur, based on the microstructure of the bones, and estimated that it would have had a wingspan of about 2.5–3 metres (8 ft 2 in–9 ft 10 in). By modern standards, the remains are too fragmentary to calculate a reliable wingspan estimate, but Cimoliornis diomedeus was undoubtedly the largest known pterosaur until the 1857 discovery of larger Ornithocheirus species.Coloborhynchus
Coloborhynchus is a genus in the pterosaur family Ornithocheiridae, and is known from the Lower Cretaceous of England (Valanginian age, 140-136 million years ago), and depending on which species are included, possibly the Albian and Cenomanian ages (113-93.9 million years ago) as well. It is the largest known toothed pterosaur.Cretornis
Cretornis is a pterosaur genus from the late Cretaceous period (Turonian) of the Czech Republic, dating to about 92 million years ago. It contains the single species Cretornis hlavaci.Lonchodectes
Lonchodectes (meaning "lance biter") was a genus of lonchodectid pterosaur from several formations dating to the Turonian (Late Cretaceous) of England, mostly in the area around Kent. The species belonging to it had been assigned to Ornithocheirus until David Unwin's work of the 1990s and 2000s. Several potential species are known; most are based on scrappy remains, and have gone through several other generic assignments. The genus is part of the complex taxonomy issues surrounding Early Cretaceous pterosaurs from Brazil and England, such as Amblydectes, Anhanguera, Coloborhynchus, and Ornithocheirus.Lonchodraco
Lonchodraco is a genus of pterodactyloid pterosaur from the Cretaceous of England. The genus includes species that were previously assigned to other genera.Ornithocheirae
Ornithocheirae is an extinct clade of pteranodontoid pterosaurs from the Early Cretaceous to the Late Cretaceous (middle Barremian to middle Campanian stages) of Asia, Europe, North America and South America. It was named by Harry Seeley in 1870 as a family that contains Ornithocheirus and its relatives. The name was emended to Ornithocheiridae, to match the requirements of the ICZN Code that a family-ranked clade should end with an -idae suffix. Brian Andres (2010, in press) in his review of pterosaur phylogeny, defined the name Ornithocheirae phylogenetically, as a node-based taxon consisting of the last common ancestor of Anhanguera and Ornithocheirus and all its descendants. Thus Ornithocheirae is defined to include two families, the Anhangueridae and the Ornithocheiridae, following the opinion of Alexander Kellner and Andres that these families should not be synonymized based on their original phylogenetical definitions.Ornithocheiromorpha
Ornithocheiromorpha is a group of pterosaurs within the suborder Pterodactyloidea.
The Ornithocheiromorpha was defined in 2014 by Andres and colleagues. They made Ornithocheiromorpha the most inclusive clade containing Ornithocheirus but not Pteranodon.Ornithocheirus buenzeli
"Ornithocheirus" buenzeli (often mis-spelled O. bunzeli) is a pterosaur species known from parts of a humerus (upper arm bone) and part of a lower jaw found in late Cretaceous period (Campanian) rocks of the Grünbach Formation, Austria. While it has traditionally been classified in the genus Ornithocheirus, it is more likely an azhdarchid, though due to the fragmentary nature of known fossil remains, it is considered a nomen dubium.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.In 1914, Reginald Walter Hooley reviewed the material. He, incorrectly, claimed the pelvis elements were misidentified parts of the notarium of the shoulder girdel 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.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.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. 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.Palaeornis cliftii
"Palaeornis" cliftii is a pterosaur species known from parts of a single humerus (upper arm bone) found in early Cretaceous period rocks of the upper Tunbridge Wells Sand Formation, England. "P." cliftii represents one of the earliest pterosaur discoveries in England, and has a long and complicated history of controversy and nomenclature.The name Palaeornis had previously been used for a genus of parakeet (now considered a synonym of Psittacula) by Vigors in 1825. Mantell was apparently aware of this, and in some later publications used the name "Palaeornithis" (Mantell, 1848) as a replacement.Ptenodactylus
Ptenodactylus is a scientific name which has been used for several distinct genera of animals. It may refer to:
Ptenodactylus (Gray, 1845): A junior synonym of the lizard genus Pristidactylus
"Ptenodactylus" (Seeley, 1869): A nomen nudum which in the 19th century was used to refer to at least 21 species of pterosaur including:"Ptenodactylus" brachyrhinus: A synonym of Ornithocheirus brachyrhinus (nomen dubium)
"Ptenodactylus" capito: A synonym of Ornithocheirus capito
"Ptenodactylus" colorhinus: A synonym of Camposipterus colorhinus.
"Ptenodactylus" crassidens: A synonym of Ornithocheirus crassidens. (nomen dubium)
"Ptenodactylus" cuvieri: A synonym of Cimoliopterus cuvieri.
"Ptenodactylus" dentatus: A synonym of Ornithocheirus dentatus. (nomen dubium)
"Ptenodactylus" enchorhynchus: A synonym of Ornithocheirus enchorhynchus (nomen dubium)
"Ptenodactylus" eurygnathus: A synonym of Ornithocheirus eurygnathus. (nomen dubium)
"Ptenodactylus" fittoni: A synonym of Pterodactylus fittoni (nomen dubium)
"Ptenodactylus" machaerorhynchus: A synonym of Lonchodraco machaerorhynchus
"Ptenodactylus macrorhinus": A nomen nudum
"Ptenodactylus" microdon: A synonym of Lonchodraco microdon
"Ptenodactylus" nasutus: A synonym of Camposipterus nasutus
"Ptenodactylus" oweni: A synonym of Lonchodraco microdon
"Ptenodactylus" oxyrhinus: A synonym of Ornithocheirus oxyrhinus (nomen dubium)
"Ptenodactylus" platystomus: A synonym of Ornithocheirus platystomus.
"Ptenodactylus" polyodon: A synonym of Ornithocheirus polydon
"Ptenodactylus" scaphorhynchus: A synonym of Ornithocheirus scaphorhynchus. (nomen dubium)
"Ptenodactylus" sedgwicki: A synonym of Camposipterus sedgwicki.
"Ptenodactylus" tenuirostris: A synonym of Ornithocheirus tenuirostris (nomen dubium)
"Ptenodactylus" woodwardi: A synonym of Pterodactylus woodwardi (nomen dubium)Serradraco
Serradraco is a genus of Early Cretaceous pterodactyloid pterosaur living in the area of present England. Named by Rigal et al. in 2017 with the description of a second specimen, it contains a single species, S. sagittirostris, which was formerly considered a species of Lonchodectes, L. sagittirostris.The second specimen, BEXHM 2015.18, consists of a small fragment of jaw with three teeth; six complete caudal vertebrae fused together and two fragmentary caudal vertebrae in articulation; a distal left ulna; a right proximal syncarpal; portions of a minimum of three phalanges and two indeterminate elements.Tropeognathus
Tropeognathus is a genus of large pterosaurs from the late Early Cretaceous of South America. It was a member of the Ornithocheiridae (alternately Anhangueridae), a group of pterosaurs known for their keel-tipped snouts, and was closely related to species of the genus Anhanguera. The type and only species is Tropeognathus mesembrinus; a second species, Tropeognathus robustus, is now considered to belong to Anhanguera. Fossils of Tropeognathus have been recovered from the fossiliferous Romualdo Formation of the Araripe Basin in northeastern Brazil.