Ornithocheirus

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Ornithocheirus_table_infobox_0

Ornithocheirus

Temporal range: Early Cretaceous, 105–100 Ma PreꞒ O S D C P T J K Pg N

Ornithocheirus_header_cell_0_0_0

Scientific classification OrnithocheirusOrnithocheirus_header_cell_0_1_0
Kingdom:Ornithocheirus_cell_0_2_0 AnimaliaOrnithocheirus_cell_0_2_1
Phylum:Ornithocheirus_cell_0_3_0 ChordataOrnithocheirus_cell_0_3_1
Order:Ornithocheirus_cell_0_4_0 PterosauriaOrnithocheirus_cell_0_4_1
Suborder:Ornithocheirus_cell_0_5_0 PterodactyloideaOrnithocheirus_cell_0_5_1
Family:Ornithocheirus_cell_0_6_0 OrnithocheiridaeOrnithocheirus_cell_0_6_1
Subfamily:Ornithocheirus_cell_0_7_0 Ornithocheirinae

Seeley, 1870Ornithocheirus_cell_0_7_1

Genus:Ornithocheirus_cell_0_8_0 †Ornithocheirus

Seeley, 1869Ornithocheirus_cell_0_8_1

Type speciesOrnithocheirus_header_cell_0_9_0
SpeciesOrnithocheirus_header_cell_0_10_0
SynonymsOrnithocheirus_header_cell_0_11_0

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 UK and possibly Morocco. Ornithocheirus_sentence_0

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. Ornithocheirus_sentence_1

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, though a specimen referred to O. cf. Ornithocheirus_sentence_2

simus is also known from Morocco. Ornithocheirus_sentence_3

Because O. simus was originally named based on poorly preserved fossil material, the genus Ornithocheirus has suffered enduring problems of zoological nomenclature. Ornithocheirus_sentence_4

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. Ornithocheirus_sentence_5

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. Ornithocheirus_sentence_6

Discovery and naming Ornithocheirus_section_0

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. Ornithocheirus_sentence_7

Decomposing pterosaur cadavers, floating on the sea surface, had gradually lost individual bones that sank to the bottom of the sea. Ornithocheirus_sentence_8

Water currents then moved the bones around, eroding and polishing them, until they were at last covered by more sand and fossilised. Ornithocheirus_sentence_9

Even the largest of these remains were damaged and difficult to interpret. Ornithocheirus_sentence_10

They had been assigned to the genus Pterodactylus, as was common for any pterosaur species described in the early and middle 19th century. Ornithocheirus_sentence_11

Young researcher Harry Govier Seeley was commissioned to bring order to the pterosaur collection of the Sedgwick Museum in Cambridge. Ornithocheirus_sentence_12

He soon concluded that it was best to create a new genus for the Cambridge Greensand material that he named Ornithocheirus (meaning "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. Ornithocheirus_sentence_13

To distinguish the best pieces in the collection, and partly because they had already been described as species by other scientists. Ornithocheirus_sentence_14

Between the years 1869 and 1870, Seeley 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. tenuirostris, O. machaerorhynchus, O. platystomus, O. microdon, O. oweni and O. huxleyi, thus 27 in total. Ornithocheirus_sentence_15

As yet Seeley did not designate a type species. Ornithocheirus_sentence_16

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. Ornithocheirus_sentence_17

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. Ornithocheirus_sentence_18

In 1874, he created two new genera: Coloborhynchus and Criorhynchus. Ornithocheirus_sentence_19

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. Ornithocheirus_sentence_20

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. Ornithocheirus_sentence_21

Seeley did not accept Owen's position. Ornithocheirus_sentence_22

In 1881 he designated O. simus the type species of Ornithocheirus and named a new separate species called O. Ornithocheirus_sentence_23 bunzeli. Ornithocheirus_sentence_24

In 1888, Edwin Tulley Newton reassigned several existing species names into Ornithocheirus, which created new combinations: O. clavirostris, O. daviesii, O. sagittirostris, O. validus, O. giganteus, O. Ornithocheirus_sentence_25 clifti, O. diomedeus, O. nobilis, O. curtus, O. macrorhinus and O. hlavaci. Ornithocheirus_sentence_26

He also reassigned the species O. umbrosus and O. harpyia into Ornithocheirus, which were formerly species given to the genus Pteranodon by Edward Drinker Cope back in 1872. Ornithocheirus_sentence_27

In 1914 Reginald Walter Hooley made a new attempt to structure the large number of species. Ornithocheirus_sentence_28

Hooley synonymized Owen's Criorhynchus to Ornithocheirus, in which he also sunk Coloborhynchus into that genus, meaning that the only generic name he kept was Ornithocheirus. Ornithocheirus_sentence_29

To allow for a greater differentiation, Hooley created two new genera, again based on jaw form: Lonchodectes and Amblydectes. Ornithocheirus_sentence_30

The genus Lonchodectes (meaning "lance biter") consisted of the former species Pterodactylus compressirostris, and Pterodactylus giganteus, which were reassigned as Lonchodectes compressirostris, the type species, and Lonchodectes giganteus, in addition, Hooley also named a new separate species called L. daviesii. Ornithocheirus_sentence_31

The genus Amblydectes (meaning "blunt biter") also consisted of three species: A. platystomus, A. crassidens and A. eurygnathus. Ornithocheirus_sentence_32

Hooley's classification however, was rarely applied later in the century, and therefore paleontologists weren't aware of it, and kept subsuming all the poorly preserved and confusing material under the name Ornithocheirus. Ornithocheirus_sentence_33

In 1964, a Russian-language overview of Pterosauria designated the species Lonchodectes compressirostris, which was identified as Pterodactylus compressirostris in the overview, as the type species of Ornithocheirus, which was then followed by Kuhn in 1967, and Wellnhofer in 1978, yet those authors weren't aware that back in 1881, Seeley made already made the species P. simus as the type species of Ornithocheirus, in which defined the new combination of O. simus. Ornithocheirus_sentence_34

From the seventies onwards many new pterosaur fossils were found in Brazil in deposits slightly older than the Cambridge Greensand, 110 million years old. Ornithocheirus_sentence_35

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. Ornithocheirus_sentence_36

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. Ornithocheirus_sentence_37

Several European researchers concluded that this was indeed the case. Ornithocheirus_sentence_38

Unwin revived Coloborhynchus and Michael Fastnacht Criorhynchus, each author ascribing Brazilian species to these genera. Ornithocheirus_sentence_39

However, in 2000 Unwin stated that Criorhynchus could not be valid. Ornithocheirus_sentence_40

Referring to Seeley's designation of 1881 he considered Ornithocheirus simus, holotype CAMSM B.54428, to be the type species. Ornithocheirus_sentence_41

This also made it possible to revive Lonchodectes, using as type the former O. compressirostris, which then became L. compressirostris. Ornithocheirus_sentence_42

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. Ornithocheirus_sentence_43

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. Ornithocheirus_sentence_44

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. Ornithocheirus_sentence_45

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. Ornithocheirus_sentence_46

Formerly assigned species Ornithocheirus_section_1

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. Ornithocheirus_sentence_47

They also considered O. platyrhinus a junior synonym of O. simus. Ornithocheirus_sentence_48

Misassigned species: Ornithocheirus_sentence_49

Ornithocheirus_unordered_list_0

  • O. compressirostris (Hooley, 1914) = Pterodactylus compressirostris Owen, 1851 [now classified as LonchodectesOrnithocheirus_item_0_0
  • O. crassidens Seeley, 1870 = [now classified as AmblydectesOrnithocheirus_item_0_1
  • O. cuvieri (Seeley, 1870) = Pterodactylus cuvieri Bowerbank, 1851 [now classified as CimoliopterusOrnithocheirus_item_0_2
  • O. curtus (Hooley, 1914) = Pterodactylus curtus Owen, 1874Ornithocheirus_item_0_3
  • O. giganteus (Owen, 1879) = Pterodactylus giganteus Bowerbank, 1846 [now classified as LonchodracoOrnithocheirus_item_0_4
  • "O." hilsensis Koken, 1883 = indeterminate NeotheropodaOrnithocheirus_item_0_5
  • O. mesembrinus (Wellnhofer, 1987) = Tropeognathus mesembrinus Wellnfofer, 1987Ornithocheirus_item_0_6
  • O. nobilis (Owen, 1869) = Pterodactylus nobilis Owen 1869Ornithocheirus_item_0_7
  • O. sagittirostris (Seeley, 1874) [now classified as SerradracoOrnithocheirus_item_0_8
  • O. simus (Owen, 1861) [originally Pterodactylus (type)Ornithocheirus_item_0_9
  • O. sedgwicki (Owen, 1859) = Pterodactylus sedgwickii Owen 1859 [now classified as AerodracoOrnithocheirus_item_0_10
  • "O." wiedenrothi Wild, 1990 = [now classified as TargaryendracoOrnithocheirus_item_0_11

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. Ornithocheirus_sentence_50

O. Ornithocheirus_sentence_51 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. Ornithocheirus_sentence_52

Description Ornithocheirus_section_2

The type species, Ornithocheirus simus, is only known from fragmentary jaw tips. Ornithocheirus_sentence_53

It bore a distinctive convex "keeled" crest on its snout similar to its relatives. Ornithocheirus_sentence_54

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. Ornithocheirus_sentence_55

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. Ornithocheirus_sentence_56

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. Ornithocheirus_sentence_57

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. Ornithocheirus_sentence_58

A related species called Tropeognathus had a wingspan measuring about 27 feet (8.2 m) wide, making it the largest toothed pterosaur known. Ornithocheirus_sentence_59

Classification Ornithocheirus_section_3

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. Ornithocheirus_sentence_60

In 2019, the description of the new ornithocheirid Ferrodraco by Pentland et al. Ornithocheirus_sentence_61

had made paleontologists reclassify the family Ornithocheiridae. Ornithocheirus_sentence_62

In the analysis, a topology placed Ornithocheirus within the subfamily Ornithocheirinae in a more derived position than Coloborhynchus, which contradicts the anterior topology by Andres & Myers in 2013. Ornithocheirus_sentence_63

See also Ornithocheirus_section_4

Ornithocheirus_unordered_list_1


Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Ornithocheirus.