Coloborhynchus
Encyclopedia
Coloborhynchus is a genus
in the pterosaur
family Ornithocheiridae
, and is known from the Lower Cretaceous of England
(Albian
age, 98 million years ago), and possibly the Aptian
age (112-99 million years ago) of Brazil
and Texas
, depending on which species are included.
Like the related Anhanguera
and Uktenadactylus
, the tip of the snout flared out into a wider rosette, in contrast to the narrow posterior jaws. Also like its close relatives, Coloborhynchus had a keel-shaped crest on the front of its jaws, though it was broad and thinned from base to top, rather than the uniformly thin crests of its relatives. This kind of thickened crest is also seen in Siroccopteryx moroccensis, which may be its closest relative or a member of the same genus. It also had a straight, rather than curved, front margin, unlike its relatives, and begins at the tip of the snout, rather than further back as in other species.
A second specimen showing all of these same unique features was reported to Brazilian paleontologist Alexander Kellner
by Darren Naish in 2007, and likely represents a second specimen of C. clavirostris, though it has not yet been described.
The possible species Coloborhynchus capito represents the largest known ornithocheirid, and indeed the largest toothed pterosaur known. A referred specimen from the Cambridge Greensand
of England
described in 2011 consists of a very large upper jaw tip which displays the tooth characteristics that distinguish C. capito from other species. The jaw tip is nearly 10 cm tall and 5.6 cm wide, with teeth up to 1.3 cm in base diameter. If the proportions of this specimen were consistent with other known species of Coloborhycnhus, the total skull length could have been up to 75 cm, leading to an estimated wingspan of 7 metres (23 ft).
pterosaurs named during the 19th century, Coloborhynchus has a highly convoluted history of classification. Over the years numerous species have been assigned to it, and often, species have been shuffled between Coloborhynchus and related genera by various researchers.
In 1874 Richard Owen
, rejecting the creation by Harry Govier Seeley of the genus Ornithocheirus
, named a species Coloborhynchus clavirostris based on holotype
BMNH 1822, a partial snout from the Hastings Beds of the Wealden Group
of East Sussex
, England
. The genus name means "maimed beak", a reference to the damaged and eroded condition of the fossil; the specific name means "key snout", referring to its form in cross-section. Owen also reclassified Ornithocheirus cuvieri and O. sedgwickii as species within the genus Coloborhycnhus, though he did not designate any of these three as the type species
. Owen considered the defining trait of the genus to be the location of the front tooth pairs high on the side of the upper jaws. However, in 1913 Reginald Walter Hooley concluded that this location was an artefact of the erosion and that the genus was indistinguishable from Criorhynchus simus, the second genus and species Owen erected in 1874. Hooley also ignored Owen's re-assignment of the two former Ornithocheirus species, leaving them in that genus. In 1967, Kuhn agreed with Hooley that Coloborhynchus clavirostris was a synonym of Criorhynchus simus. Furthermore, Kuhn was the first to formally designate C. clavirostris as the type species of the genus, rather than one of the Ornithocheirus species. Most later researchers followed these opinions, regarding Coloborhynchus as invalid relative to Criorhynchus.
This changed in 1994 when Yuong-Nam Lee named Coloborhynchus wadleighi for a snout found in 1992 in the Albian
age Paw Paw formation
Texas
. The revival of the genus meant that of several related species, then assigned to other genera, had to be re-evaluated to determine whether or not they actually belonged to Coloborhynchus. In 2008, Taissa Rodrigues and Alexander Kellner re-formulated the key features of Coloborhynchus, again based mainly on the unique positions of the tooth sockets. Rodrigues and Kellner argued that Lee's C. wadleighi, which possessed some differences in the skull and teeth from C. clavirostris, and from an earlier time period, belonged in its own genus, which they named Uktenadactylus
.
A partial lower jaw originally named Tropeognathus robustus from the Romualdo Member of the Santana Formation
in Brazil
was assigned to Coloborhycnhus in 2001 by Fastnacht, as Coloborhynchus robustus. In 2002, David Unwin supported this position, and also synonymized the more well-known species Anhanguera
piscator with C. robustus. Rodrigues and Kellner disagreed with this classification, however, noting that both did not possess the unique straightened crest beginning at the snout tip, or sideways pointed teeth, of C. clavirostris. Instead, Rodrigues and Kellner regarded both Anhanguera robustus and Anhanguera piscator as valid species of Anhanguera.
Another Brazilian species from the Romualdo Member was named Coloborhynchus speilbergi by Veldmeijer in 2003. It shares one or two characters in common with C. clavirostris (such as a flattened upper surface of the snout), though Rodrigues and Kellner regarded them as dubious, and noted that they are also present in related species and so are not unique to Coloborhynchus. Rodrigues and Kellner also noted that C. speilbergi didn't have as high a tooth row (exposing the palate) as the type species. Its crest is also very thin, similar to Anhanguera, to which genus Kellner assigned it in 2006. Similarly, Kellner excluded C. araripensis (formerly assigned to the genus Santanadactylus
from the genus, based on lack of comparable diagnostic features. Unwin, in 2001, assigned the species Siroccopteryx moroccensis to Coloborhycnhus, based on its similarity to C. wadleighi (aka Uktenadactylus). Kellner, who regarded Uktenadactylus as a distinct genus in 2008, also regarded Siroccopteryx as distinct, and noted that like the other species assigned to Coloborhynchus, lacked its unique characteristics of the tooth row, a position also supported by Fastnacht in 2001.
Finally, Unwin (in 2001) also re-assigned the two other species from the Cambridge Greensand
to Coloborhycnhus: C. capito and C. sedgwickii, the second of which being one of the original members of the genus according to Richard Owen in 1874. According to Kellner, C. capito is too incomplete to fully compare to C. claviraostris, and its precise classification is open to debate. He noted that C. sedgwicki does not possess the unique features of C. clavirostris (in fact it lacks a crest altogether), and may instead belong to the same genus as "Ornithocheirus" compressirostris (=Lonchodectes
).
Species assigned to Coloborhynchus in the past include:
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in the 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...
family Ornithocheiridae
Ornithocheiridae
Ornithocheiridae is a group of pterosaurs within the suborder Pterodactyloidea. They were among the last pterosaurs to possess teeth.-Classification:Listing of genera after Unwin , except where noted.* Family Ornithocheiridae** ?Aetodactylus...
, and is known from the Lower Cretaceous 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...
(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...
age, 98 million years ago), and possibly the Aptian
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...
age (112-99 million years ago) 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...
and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, depending on which species are included.
Description
The type specimen of Coloborhynchus is known only from a partial upper jaw. Therefore, according to Rodrigues and Kellner's 2008 re-evaluation on Coloborhynchus clavirostris, it can only be differentiated from its relatives based on its unique combination of tooth socket positions. In Coloborhynchus, the two front teeth pointed forward and were higher on the jaw than the other teeth, while the next three pairs of teeth pointed to the sides. The final two (preserved) pairs of teeth pointed downward. Finally, a unique oval depression was located below the first pair of teeth.Like the related 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...
and Uktenadactylus
Uktenadactylus
Uktenadactylus is a genus of pterodactyloid pterosaur from the Lower Cretaceous Paw Paw Formation of Texas.In 1994 Yuong Nam-Lee named a new species within the genus Coloborhynchus: Coloborhynchus wadleighi, based on a partial snout found in 1992 in Albian layers in Tarrant County, holotype SMU...
, the tip of the snout flared out into a wider rosette, in contrast to the narrow posterior jaws. Also like its close relatives, Coloborhynchus had a keel-shaped crest on the front of its jaws, though it was broad and thinned from base to top, rather than the uniformly thin crests of its relatives. This kind of thickened crest is also seen in Siroccopteryx moroccensis, which may be its closest relative or a member of the same genus. It also had a straight, rather than curved, front margin, unlike its relatives, and begins at the tip of the snout, rather than further back as in other species.
A second specimen showing all of these same unique features was reported to Brazilian paleontologist Alexander Kellner
Alexander Kellner
Alexander Wilhelm Armin Kellner is a Liechtensteinian/Brazilian paleontologist, a leading expert in the field of the study of pterosaurs....
by Darren Naish in 2007, and likely represents a second specimen of C. clavirostris, though it has not yet been described.
The possible species Coloborhynchus capito represents the largest known ornithocheirid, and indeed the largest toothed pterosaur known. A referred specimen 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...
described in 2011 consists of a very large upper jaw tip which displays the tooth characteristics that distinguish C. capito from other species. The jaw tip is nearly 10 cm tall and 5.6 cm wide, with teeth up to 1.3 cm in base diameter. If the proportions of this specimen were consistent with other known species of Coloborhycnhus, the total skull length could have been up to 75 cm, leading to an estimated wingspan of 7 metres (23 ft).
Classification and species
Like many ornithocheiroidOrnithocheiroidea
Ornithocheiroidea is an extinct group of pterosaurs within the suborder Pterodactyloidea.-Locomotion:Ornithocheiroids, like other pterosaurs, are considered to have been skilled fliers as well as adept at moving on the ground...
pterosaurs named during the 19th century, Coloborhynchus has a highly convoluted history of classification. Over the years numerous species have been assigned to it, and often, species have been shuffled between Coloborhynchus and related genera by various researchers.
In 1874 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...
, rejecting the creation by Harry Govier Seeley of the genus Ornithocheirus
Ornithocheirus
Ornithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
, named a species Coloborhynchus clavirostris based on 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...
BMNH 1822, a partial snout from the Hastings Beds of the Wealden Group
Wealden Group
The Wealden Group is a group in the lithostratigraphy of southern England. The Wealden group consists of paralic to continental facies sedimentary rocks of Valanginian to Barremian age and thus forms part of the English Lower Cretaceous. It is composed of alternating sands and clays...
of East Sussex
East Sussex
East Sussex is a county in South East England. It is bordered by the counties of Kent, Surrey and West Sussex, and to the south by the English Channel.-History:...
, 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...
. The genus name means "maimed beak", a reference to the damaged and eroded condition of the fossil; the specific name means "key snout", referring to its form in cross-section. Owen also reclassified Ornithocheirus cuvieri and O. sedgwickii as species within the genus Coloborhycnhus, though he did not designate any of these three as the 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...
. Owen considered the defining trait of the genus to be the location of the front tooth pairs high on the side of the upper jaws. However, in 1913 Reginald Walter Hooley concluded that this location was an artefact of the erosion and that the genus was indistinguishable from Criorhynchus simus, the second genus and species Owen erected in 1874. Hooley also ignored Owen's re-assignment of the two former Ornithocheirus species, leaving them in that genus. In 1967, Kuhn agreed with Hooley that Coloborhynchus clavirostris was a synonym of Criorhynchus simus. Furthermore, Kuhn was the first to formally designate C. clavirostris as the type species of the genus, rather than one of the Ornithocheirus species. Most later researchers followed these opinions, regarding Coloborhynchus as invalid relative to Criorhynchus.
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...
age Paw Paw formation
Paw Paw Formation
The Paw Paw Formation is a geological formation in Texas whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:* Pawpawsaurus campbelli - "Skull."...
Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. The revival of the genus meant that of several related species, then assigned to other genera, had to be re-evaluated to determine whether or not they actually belonged to Coloborhynchus. In 2008, Taissa Rodrigues and Alexander Kellner re-formulated the key features of Coloborhynchus, again based mainly on the unique positions of the tooth sockets. Rodrigues and Kellner argued that Lee's C. wadleighi, which possessed some differences in the skull and teeth from C. clavirostris, and from an earlier time period, belonged in its own genus, which they named Uktenadactylus
Uktenadactylus
Uktenadactylus is a genus of pterodactyloid pterosaur from the Lower Cretaceous Paw Paw Formation of Texas.In 1994 Yuong Nam-Lee named a new species within the genus Coloborhynchus: Coloborhynchus wadleighi, based on a partial snout found in 1992 in Albian layers in Tarrant County, holotype SMU...
.
A partial lower jaw originally named Tropeognathus robustus from the Romualdo Member of 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...
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...
was assigned to Coloborhycnhus in 2001 by Fastnacht, as Coloborhynchus robustus. In 2002, David Unwin supported this position, and also synonymized the more well-known species Anhanguera
Anhangüera
Anhangüera originates from a word in the Tupi language which was the nickname given by Brazilian Indians to an explorer and "bandeirante", Bartolomeu Bueno da Silva .It may also refer to:* Anhanguera, Goiás, a municipality in the state of Goiás...
piscator with C. robustus. Rodrigues and Kellner disagreed with this classification, however, noting that both did not possess the unique straightened crest beginning at the snout tip, or sideways pointed teeth, of C. clavirostris. Instead, Rodrigues and Kellner regarded both Anhanguera robustus and Anhanguera piscator as valid species of Anhanguera.
Another Brazilian species from the Romualdo Member was named Coloborhynchus speilbergi by Veldmeijer in 2003. It shares one or two characters in common with C. clavirostris (such as a flattened upper surface of the snout), though Rodrigues and Kellner regarded them as dubious, and noted that they are also present in related species and so are not unique to Coloborhynchus. Rodrigues and Kellner also noted that C. speilbergi didn't have as high a tooth row (exposing the palate) as the type species. Its crest is also very thin, similar to Anhanguera, to which genus Kellner assigned it in 2006. Similarly, Kellner excluded C. araripensis (formerly assigned to the genus Santanadactylus
Santanadactylus
Santanadactylus was a genus of pterodactyloid pterosaur from the Aptian-age Romualdo Member of the Lower Cretaceous Santana Formation, of Barra do Jardim, Araripe Plateau, Ceará Province, Brazil. Four species have been named, but today it is doubted they are part of the same genus...
from the genus, based on lack of comparable diagnostic features. Unwin, in 2001, assigned the species Siroccopteryx moroccensis to Coloborhycnhus, based on its similarity to C. wadleighi (aka Uktenadactylus). Kellner, who regarded Uktenadactylus as a distinct genus in 2008, also regarded Siroccopteryx as distinct, and noted that like the other species assigned to Coloborhynchus, lacked its unique characteristics of the tooth row, a position also supported by Fastnacht in 2001.
Finally, Unwin (in 2001) also re-assigned the two other species 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:...
to Coloborhycnhus: C. capito and C. sedgwickii, the second of which being one of the original members of the genus according to Richard Owen in 1874. According to Kellner, C. capito is too incomplete to fully compare to C. claviraostris, and its precise classification is open to debate. He noted that C. sedgwicki does not possess the unique features of C. clavirostris (in fact it lacks a crest altogether), and may instead belong to the same genus as "Ornithocheirus" compressirostris (=Lonchodectes
Lonchodectes
Lonchodectes was a genus of pterosaur from several formations dating to the Turonian of England, mostly in the area around Kent...
).
List of species and synonyms
Species which have been assigned to Coloborhynchus by various scientists since 2000 include:- ?C. capito (Seeley 1869) = Pterodactylus capito Sauvage 1882 = OrnithocheirusOrnithocheirusOrnithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
capito Seeley 1870 = Ptenodactylus capito Seeley 1869 - C. clavirostris Owen, 1874, the type speciesType 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...
- ?C. sedgwicki (Owen 1874) = OrnithocheirusOrnithocheirusOrnithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
sedgwicki (Newton 1888) = Pterodactylus sedgwickii Owen 1859 [also classified as Ornithocheirus] - ?C. araripensis (Wellnhofer 1985) = Santanadactylus araripensis Wellnhofer 1985 [also classified as Anhanguera]
- ?C. robustus (Wellnhofer 1987) = Tropeognathus robustus Wellnhofer 1987 [also classified as Anhanguera]
- ?C. ligabuei (Dalla Vecchia 1993) = CearadactylusCearadactylusCearadactylus is an extinct genus of large, Early Cretaceous pterosaur from South America. The type species is Cearadactylus atrox, described and named in 1985 by Giuseppe Leonardi and Guido Borgomanero. The genus name refers to the Brazilian state Ceará and combines this with Greek daktylos,...
ligabuei Dalla Vecchia 1993 [also classified as Anhanguera or Cearadactylus] - ?C. wadleighi Lee 1994 [also classified as UktenadactylusUktenadactylusUktenadactylus is a genus of pterodactyloid pterosaur from the Lower Cretaceous Paw Paw Formation of Texas.In 1994 Yuong Nam-Lee named a new species within the genus Coloborhynchus: Coloborhynchus wadleighi, based on a partial snout found in 1992 in Albian layers in Tarrant County, holotype SMU...
] - ?C. moroccensis (Mader & Kellner 1999) = Siroccopteryx moroccensis Mader & Kellner 1999
- ?C. piscator (Kellner & Tomida 2000) = Anhanguera piscatorAnhanguera (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...
Kellner & Tomida 2000 [also classified as Anhanguera or C. robustus] - ?C. spielbergi Veldmeijer 2003 [also classified as Anhanguera]
Species assigned to Coloborhynchus in the past include:
- C. cuvieri (Owen 1874) = OrnithocheirusOrnithocheirusOrnithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
sedgwicki (Newton 1888) = Pterodactylus cuvieri Bowerbank 1851 [now classified as either OrnithocheirusOrnithocheirusOrnithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
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...
]