Lonchodectes
Encyclopedia
Lonchodectes was a genus
of pterosaur
from several formations
dating to the Turonian
(Late Cretaceous
, though possibly as early as the Valanginian
) 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, and the genus is not universally accepted as distinct. 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
(and its possible synonyms Criorhynchus and Tropeognathus).
The type species
, L. compressirostris, is based on
BMNH 39410, a partial upper jaw from the Turonian-age Upper Cretaceous Upper Chalk near Kent. Richard Owen
named in 1851 as a species of Pterodactylus
; it was transferred to Ornithocheirus in 1870 by Harry Govier Seeley, before becoming the type species of Lonchodectes in Reginald Walter Hooley's 1914 review of Ornithocheirus. Confusingly, this species was also long regarded, incorrectly, as the type species of Ornithocheirus.
Hooley added two other species at this time, both of which had also been originally referred to Pterodactylus, then to Ornithocheirus: L. giganteus, a Cenomanian
-age jaw fragment; and L. daviesii, another jaw fragment, from an Albian
-age formation.
The genus acquired several more former Pterodactylus and Ornithocheirus species in the 1990s-2000s. L. sagittirostris, based on BMNH R1823, a lower jaw fragment from the ?Valanginian
-Hauterivian
-age Lower Cretaceous Hastings Beds of East Sussex
, and L. platystomus had been acquired by 2000. Two additional species based on jaw fragments, both from the Albian
-age Cambridge Greensand
, were added by 2003: L. machaerorhynchus and L. microdon, joining L. compressirostris, L. giganteus, L. platystomus, and L. sagittirostris in his listing of valid species (thus, additional dubious
species may also be referred here).
in 2003, and with the azhdarchoids, including the tapejarids
and azhdarchids
, in 2006.
Unwin considers Lonchodectes to have been a generalist
, like a seagull, with its conservative jaws and teeth (like those of the much older Pterodactylus) and small to medium size; he estimates its maximum wingspan
at about 2 m (6.6 ft). Lonchodectes had long jaws with many short teeth, and the jaws were compressed vertically, like "a pair of sugar tongs with teeth". At least some of these species had crests on their lower jaws.
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...
of 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 several formations
Rock formation
This is a list of rock formations that include isolated, scenic, or spectacular surface rock outcrops. These formations are usually the result of weathering and erosion sculpting the existing rock...
dating to the Turonian
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
(Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
, though possibly as early as the Valanginian
Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 140.2 ± 3.0 Ma and 136.4 ± 2.0 Ma...
) 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...
, mostly in the area around Kent
Kent
Kent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...
. The species belonging to it had been assigned to Ornithocheirus
Ornithocheirus
Ornithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
until David Unwin's work of the 1990s and 2000s, and the genus is not universally accepted as distinct. 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
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
issues surrounding Early Cretaceous pterosaurs from 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 England, such as Amblydectes, 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...
, 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 Ornithocheirus
Ornithocheirus
Ornithocheirus was a pterosaur from the Cretaceous period of Europe and South America...
(and its possible synonyms Criorhynchus and Tropeognathus).
History and species
Numerous species have been referred to this genus over time, and only those more widely connected with the genus are included here.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...
, L. compressirostris, is based on
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 39410, a partial upper jaw from the Turonian-age Upper Cretaceous Upper Chalk near Kent. 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...
named in 1851 as a species of 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...
; it was transferred to Ornithocheirus in 1870 by Harry Govier Seeley, before becoming the type species of Lonchodectes in Reginald Walter Hooley's 1914 review of Ornithocheirus. Confusingly, this species was also long regarded, incorrectly, as the type species of Ornithocheirus.
Hooley added two other species at this time, both of which had also been originally referred to Pterodactylus, then to Ornithocheirus: L. giganteus, a Cenomanian
Cenomanian
The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
-age jaw fragment; and L. daviesii, another jaw fragment, from an 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 formation.
The genus acquired several more former Pterodactylus and Ornithocheirus species in the 1990s-2000s. L. sagittirostris, based on BMNH R1823, a lower jaw fragment from the ?Valanginian
Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 140.2 ± 3.0 Ma and 136.4 ± 2.0 Ma...
-Hauterivian
Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 136.4 ± 2 Ma and 130 ± 1.5 Ma...
-age Lower Cretaceous Hastings Beds 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:...
, and L. platystomus had been acquired by 2000. Two additional species based on jaw fragments, both from 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...
-age 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:...
, were added by 2003: L. machaerorhynchus and L. microdon, joining L. compressirostris, L. giganteus, L. platystomus, and L. sagittirostris in his listing of valid species (thus, additional dubious
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
species may also be referred here).
Classification
The genus is poorly known and not universally accepted, as noted above. In Peter Wellnhofer's 1991 The Illustrated Encyclopedia of Pterosaurs the other major recent synopsis of pterosaurs, written before Unwin's work, the species are included with Ornithocheirus (because of L. compressirostris being thought to be the type species), and are in fact the main fossils illustrated to represent the genus. Unwin placed them in their own family, Lonchodectidae, which he grouped with the ctenochasmatoidsCtenochasmatoidea
Ctenochasmatoidea is a group of pterosaurs within the suborder Pterodactyloidea.-Classification:Cladogram after Unwin ....
in 2003, and with the azhdarchoids, including the tapejarids
Tapejaridae
Tapejaridae are a family of pterodactyloid pterosaurs from the early Cretaceous period. Members are currently known from Brazil and China, where the most primitive genera are found, indicating that the family has an Asian origin....
and azhdarchids
Azhdarchidae
Azhdarchidae 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...
, in 2006.
Paleobiology
Generalist and specialist species
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources . A specialist species can only thrive in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either...
, like a seagull, with its conservative jaws and teeth (like those of the much older Pterodactylus) and small to medium size; he estimates its maximum wingspan
Wingspan
The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...
at about 2 m (6.6 ft). Lonchodectes had long jaws with many short teeth, and the jaws were compressed vertically, like "a pair of sugar tongs with teeth". At least some of these species had crests on their lower jaws.
External links
- Upper Cretaceous species of Lonchodectes (scroll down), The Pterosaur Database. Accessed 2007-02-10
- Upper Cretaceous species of Lonchodectes (scroll down), The Pterosaur Database. Accessed 2007-02-10
- Re: Pterosaur Help, a posting from George OlshevskyGeorge OlshevskyGeorge Olshevsky is a freelance editor, writer, publisher, amateur paleontologist, and mathematician living in San Diego, California.Olshevsky maintains the comprehensive online Dinosaur Genera List...
on the Dinosaur Mailing List, which, although incomplete, should give some idea as to the complexity of the taxonomy here. Additional, even more dubious species are included. Accessed 2007-02-10