Ornithocheirus
Encyclopedia
- "Osteornis" redirects here. It is also found as a generic term for bird fossils in old texts.
Ornithocheirus (from Greek "ορνις", meaning bird, and "χειρ", meaning hand) was a pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
from the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. Based on poor fossil material, the genus has caused enduring problems of zoological nomenclature.
Fossil remains currently classified as Ornithocheirus have been recovered mainly from the Cambridge Greensand
Cambridge Greensand
The Cambridge Greensand is a geological formation in England whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:...
of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, dating to the beginning of the Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
stage of the late Cretaceous period, about 110 million years ago. Additional fossils from the Santana Formation
Santana Formation
The Santana Formation is a geologic Lagerstätte in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The geological formation, named after the village of Santana do Cariri, lies at the base of the Araripe Plateau...
of Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, dating to 112-108 million years ago, have been classified as species of Ornithocheirus.
Description
Both O. simus and O. mesembrinus bore distinctive convex "keeled" crests on their snouts. The upper crests arose from the snout tip and extended back to the nostril. An additional, smaller crest projected down from the lower jaw at the symphysis
Symphysis
A symphysis is a fibrocartilaginous fusion between two bones. It is a type of cartilaginous joint, specifically a secondary cartilaginous joint.1.A symphysis is an amphiarthrosis, a slightly movable joint.2.A growing together of parts or structures...
("chin" area). While many ornithocheirids had a small, rounded bony crest projecting from the back of the skull, this was particularly large and well-developed in Ornithocheirus.
Unlike the related Anhanguera and Coloborhynchus, which had an expanded rosette of teeth at the jaw tips, Ornithocheirus had straight jaws that narrowed toward the tip. Also unlike related pterosaurs, the teeth of Ornithocheirus were mostly vertical, rather than set at an outward-pointing angle. They also had fewer teeth than related species.
The type specimen of Ornithocheirus simus is represented only by a broken piece of the upper jaw tip. While it does preserve several characteristic features of Ornithocheirus, it is nearly identical to comparable bones in o. mesembrinus, making clear distinction between these two species impossible.
Discovery and naming
During the 19th century, in England many fragmentary pterosaur fossils were found in the Cambridge GreensandCambridge Greensand
The Cambridge Greensand is a geological formation in England whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:...
, 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
Pterodactylus
Pterodactylus is a genus of pterosaurs, whose members are popularly known as pterodactyls. It was the first to be named and identified as a flying reptile...
, 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
Cambridge
The city of Cambridge is a university town and the administrative centre of the county of Cambridgeshire, England. It lies in East Anglia about north of London. Cambridge is at the heart of the high-technology centre known as Silicon Fen – a play on Silicon Valley and the fens surrounding the...
. 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
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the 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
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
. 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
Coloborhynchus
Coloborhynchus is a genus in the pterosaur family Ornithocheiridae, and is known from the Lower Cretaceous of England , and possibly the Aptian age of Brazil and Texas, depending on which species are included.-Description:The type specimen of Coloborhynchus is known only from a partial upper jaw...
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
Edward Newton
Sir Edward Newton KCMG was a British colonial administrator and ornithologist.He was born at Elveden Hall, Suffolk the sixth and youngest son of William Newton, MP. He was the brother of ornithologist Alfred Newton....
renamed several existing species names into: Ornithocheirus clavirostris, O. daviesii, O. sagittirostris, O. validus and O. giganteus; as new species he created: O. clifti, O. diomedeus, O. nobilis and O. curtus. Others had already named an O. umbrosus, O. harpyia, O. macrorhinus and O. hilsensis and would create an O. hlavaci, O. wiedenrothi and O. mesembrinus.
Lonchodectes
Lonchodectes was a genus of pterosaur from several formations dating to the Turonian of England, mostly in the area around Kent...
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. In 1978 Peter Wellnhofer
Peter Wellnhofer
Peter Wellnhofer is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of Archaeopteryx or "Urvogel", the first known bird...
, assuming no type species had been designated, made Ornithocheirus compressirostris the type.
From the seventies onwards many new pterosaur fossils were found in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, from formations about the same age as the Cambridge Greensand, 110 million years old. Contrary to 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
Anhanguera (pterosaur)
Anhanguera is a genus of pterodactyloid pterosaur known from the Lower-Cretaceous Santana Formation of Brazil, with referred specimens found in the Upper Chalk Formation and Cambridge Greensand of the UK...
. 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
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the 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. This position has not universally been accepted. Brazilian workers also typically reject the identification of their genera with European types. Unwin, and this caused no controversy, reaffirmed that most Ornithocheirus species are nomina dubia
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
, names that are invalid because the fossils they refer to lack sufficient diagnostic features.
As a result, though over forty species have been named in the genus Ornithocheirus over the years, not a single one of them, not even O. simus, is currently recognized as valid by all pterosaur researchers. Often, there is a total lack of consensus; e.g. Tropeognathus mesembrinus named by Peter Wellnhofer in 1987 has afterwards been considered Ornithocheirus mesembrinus by David Unwin in 2003 (making Tropeognathus a junior synonym) http://dml.cmnh.org/2003Sep/msg00388.html, but as Anhanguera mesembrinus by Alexander Kellner
Alexander Kellner
Alexander Wilhelm Armin Kellner is a Liechtensteinian/Brazilian paleontologist, a leading expert in the field of the study of pterosaurs....
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 denied that O. simus is the type species in favor of O. compressirostris (alternately Lonchodectes), and used the names Criorhynchus simus and Cr. mesembrinus. Kellner in 2000 again recognized Tropeognathus as a valid genus.
Species currently or possibly assigned to Ornithocheirus:
- ?O. clifti (MantellGideon MantellGideon Algernon Mantell MRCS FRS was an English obstetrician, geologist and palaeontologist...
1835) = Palaeornis clifti Mantell 1835 - ?O. cuvieri (Bowerbank 1851) = Pterodactylus cuvieri Bowerbank 1851 [also classified as ColoborhynchusColoborhynchusColoborhynchus is a genus in the pterosaur family Ornithocheiridae, and is known from the Lower Cretaceous of England , and possibly the Aptian age of Brazil and Texas, depending on which species are included.-Description:The type specimen of Coloborhynchus is known only from a partial upper jaw...
or AnhangueraAnhanguera (pterosaur)Anhanguera is a genus of pterodactyloid pterosaur known from the Lower-Cretaceous Santana Formation of Brazil, with referred specimens found in the Upper Chalk Formation and Cambridge Greensand of the UK...
] - ?O. sedgwicki (Owen 1859) = Pterodactylus sedgwickii Owen 1859 [also classified as Coloborhynchus]
- O. simus (OwenRichard OwenSir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
, 1861) [originally PterodactylusPterodactylusPterodactylus is a genus of pterosaurs, whose members are popularly known as pterodactyls. It was the first to be named and identified as a flying reptile...
] (typeType speciesIn biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
) - ?O. nobilis (Owen 1869) = Pterodactylus nobilis Owen 1869
- ?O. curtus (Owen, 1870) [originally Pterodactylus]
- ?O. hlavaci Fritsch 1880
- "O." bunzeli Seeley 1881 [possibly an azhdarchidAzhdarchidaeAzhdarchidae is a family of pterosaurs known primarily from the late Cretaceous Period, though an isolated vertebrae apparently from an azhdarchid is known from the early Cretaceous as well...
or nyctosauridNyctosauridaeNyctosauridae is a family of specialized soaring pterosaurs of the Cretaceous Period of North America and, possibly, Europe. It was named in 1889 by Henry Alleyne Nicholson and Richard Lydekker....
] - ?"O." hilsensis Koken 1883 [possibly a theropod dinosaurDinosaurDinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
] - O. mesembrinus (WellnhoferPeter WellnhoferPeter Wellnhofer is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of Archaeopteryx or "Urvogel", the first known bird...
1987) = Tropeognathus mesembrinus Wellnfofer 1987 - ?O. wiedenrothi Wild, 1990
Cimoliornis, Cretornis, and Palaeornis, misidentified as birds, have been assigned to Ornithocheirus, but they may instead be separate genera, a position held by David Unwin.
In popular culture
Ornithocheirus was the subject of an entire episode of the award-winning BBCBBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
television program Walking with Dinosaurs
Walking with Dinosaurs
Walking with Dinosaurs is a six-part documentary television miniseries that was produced by BBC, narrated by Kenneth Branagh, and first aired in the United Kingdom, in 1999. The series was subsequently aired in North America on the Discovery Channel in 2000, with Branagh's voice replaced with that...
. In Walking with Dinosaurs: A Natural History, a companion book to the series, it was claimed that several large bone fragments from the Santana Formation
Santana Formation
The Santana Formation is a geologic Lagerstätte in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The geological formation, named after the village of Santana do Cariri, lies at the base of the Araripe Plateau...
of Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
indicated that Ornithocheirus may have had a wingspan reaching almost 12 metres and a weight of a hundred kilogrammes, making it one of the largest known pterosaurs. However, the largest definite Ornithocheirus specimens known measure 6 metres in wingspan. The specimens which the producers of the program used to justify such a large size estimate are currently undescribed, and are being studied by Dave Martill and Heinz Peter Bredow. Bredow stated that he does not believe this highest estimate is likely, and that the producers likely chose the highest possible estimate because it was more "spectacular."