Streptospondylus
Encyclopedia
Streptospondylus is a genus
of tetanuran theropod dinosaur
known from the Middle Jurassic
period of France
, 161 million years ago. It was a medium-sized predator.
living in Rouen
, began to collect fossil
s. These included some theropod vertebrae and limb elements found near Honfleur
. In 1776 abbey Jean-François Dicquemare working in Le Havre
reported some similar bones, interpreted by him as the remains of dolphins and porpoises. After the death of Bachelet his collection was taken over by C. Guersent, professor of natural history
at Rouen. In 1799 the prefect
of Seine-Inférieure, count Jacques Claude Beugnot
, ordered to move it to the Muséum National d'Histoire Naturelle
in Paris
. In 1800 the collection was reported by Georges Cuvier
who combined the material with that from the collection of Dicquemare, also obtained by the Paris museum.
In 1808, Cuvier scientifically described the theropod vertebrae as the first dinosaur remains ever. However, he considered them to be crocodilian and associated them with fossils of the Teleosauridae
and the Metriorhynchidae
. In 1822, Cuvier by the work of Henry De La Bèche
became aware that these finds were very disparate, stemming from different periods. He abstained from naming them but in 1824 concluded that there were two main types. In 1825 Étienne Geoffroy Saint-Hilaire
accordingly named two crocodilian skulls as the genus Steneosaurus
, the one, specimen MNHN 8900, becoming Steneosaurus rostromajor, the other, MNHN 8902, S. rostrominor.
In 1832 however, the German paleontologist Christian Erich Hermann von Meyer
split the material. Steneosaurus rostrominor was renamed Metriorhynchus
geoffroyii while Steneosaurus rostromajor became Streptospondylus altdorfensis. To the last species the theropod remains were referred. The generic name is derived from Greek στρεπτος/streptos, "reversed", and σπονδυλος/spondylos, "vertebra", alluding to the fact that the vertebrae differed from typical crocodile elements in being opisthocoel: convex in front and concave behind. The specific name refers to Altdorf
where also some teleosaurid remains had been found. Von Meyer's name was the first binomial name (also) referring to a theropod.
In 1842 Richard Owen
pointed out that von Meyer had been incorrect in changing the original specific name and created the correct combination Streptospondylus rostromajor for Streptospondylus altdorfensis. At the same time he created a second species: Streptospondylus cuvieri based on a single damaged vertebra from the Bathonian
, found near Chipping Norton
. In 1861, Owen would refer the entire Cuvier material to S. cuvieri, despite the fact that if it were cospecific the name S. rostromajor would have priority. From that time S. cuvieri was generally accepted in the literature as the valid name, though some workers split off the theropod remains from the crocodilian bones, Edward Drinker Cope
in 1867 naming a Laelaps
gallicus and Friedrich von Huene
in 1909 a Megalosaurus
cuvieri.
In 1964, Alick Donald Walker discovered Owen's mistake, referring the entire theropod material to the new species Eustreptospondylus
divesensis which, however, had a skull not belonging to the Cuvier material as the type specimen, MNHN 1920-7. In 1977 Philippe Tacquet created the genus Piveteausaurus
for this species.
In 2001, Ronan Allain concluded that no connection could be proven between Piveteausaurus and the referred other theropod material from Normandy
. He also pointed out that the skull von Meyer had based Streptospondylus altdorfensis on was in fact a composite of bones from two species, since named Steneosaurus edwardsi Deslongchamps 1866 and Metriorynchus superciliosum Blainville 1853. Never a lectotype
had been chosen from one of the composite parts to give the name Streptospondylus priority over either one of these species. Allain used this situation to remove all the crocodilian material from the Streptospondylus type by designating the complete theropod material as the lectotype. As Steneosaurus rostromajor had been based on the composite skull, the epithet rostromajor now no longer had priority over altdorfensis. This way in 2001 Streptospondylus altdorfensis became the valid name and type species
of a theropod. Laelaps gallicus and Megalosaurus cuvieri are its objective junior synonyms.
The lectotype specimens, MNHN 8605-09, 8787-89, 8793-94, 8907, were probably found at the coast in layers of the Falaises des Vaches Noires near Calvados
, dating from the late Callovian
or early Oxfordian
, about 161 million years old. They consist of several vertebrae series, single vertebrae, a partial left pubis
and limb elements. The longest vertebra has a length of 97 millimetres, indicating a total body length of about seven metres. Also a partial left femur
, MNHN 9645, has been referred. Streptospondylus has been diagnosed by several osteological details, among which the possession of two hypapophyses on the, ventrally flat, anterior dorsal vertebrae and the particular connection between the astragalus
and the tibia
, without a posterior astragalar process but with a distinctive buttress on the tibia above the anterior process.
Owen also named four other species: S. major (1842), S. recentior, S. meyeri (both 1851), and S. grandis (1854), which however are probably based on Iguanodon
material. His S. cuvieri, of which the type specimen is lost, is today considered a nomen dubium
.
In 2010 Gregory S. Paul
renamed (as an informal name) Magnosaurus
into Streptospondylus nethercombensis.
Recent analyses indicate that Streptospondylus is a tetanuran
theropod. Allain in 2001 suggested that it was closely related to Eustreptospondylus in the Spinosauroidea. Roger Benson in 2008 and 2010 concluded that whether it is a megalosauroid
, allosauroid
, or a more primitive form cannot be determined because of its extremely fragmentary remains. Later cladistic analysis by Benson and colleagues from 2010 indicated that Streptospondylus was the sister species of Magnosaurus
within the Megalosauridae.
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 tetanuran theropod dinosaur
Dinosaur
Dinosaurs 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...
known from the Middle Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
period of France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, 161 million years ago. It was a medium-sized predator.
Discovery and naming
Streptospondylus was one of the first dinosaurs collected and is the first described, though not named. From about 1770, a certain abbey Bachelet, an amateur naturalistNaturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
living in Rouen
Rouen
Rouen , in northern France on the River Seine, is the capital of the Haute-Normandie region and the historic capital city of Normandy. Once one of the largest and most prosperous cities of medieval Europe , it was the seat of the Exchequer of Normandy in the Middle Ages...
, began to collect fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s. These included some theropod vertebrae and limb elements found near Honfleur
Honfleur
Honfleur is a commune in the Calvados department in northwestern France. It is located on the southern bank of the estuary of the Seine across from le Havre and very close to the exit of the Pont de Normandie...
. In 1776 abbey Jean-François Dicquemare working in Le Havre
Le Havre
Le Havre is a city in the Seine-Maritime department of the Haute-Normandie region in France. It is situated in north-western France, on the right bank of the mouth of the river Seine on the English Channel. Le Havre is the most populous commune in the Haute-Normandie region, although the total...
reported some similar bones, interpreted by him as the remains of dolphins and porpoises. After the death of Bachelet his collection was taken over by C. Guersent, professor of natural history
Natural history
Natural history is the scientific research of plants or animals, leaning more towards observational rather than experimental methods of study, and encompasses more research published in magazines than in academic journals. Grouped among the natural sciences, natural history is the systematic study...
at Rouen. In 1799 the prefect
Prefect
Prefect is a magisterial title of varying definition....
of Seine-Inférieure, count Jacques Claude Beugnot
Jacques Claude Beugnot
Jacques Claude, comte de Beugnot was a French politician before, during, and after the French Revolution. His son Auguste Arthur Beugnot was an historian and scholar.-Revolution:...
, ordered to move it to the Muséum National d'Histoire Naturelle
Muséum national d'histoire naturelle
The Muséum national d'Histoire naturelle is the National Museum of Natural History in Paris, France.- History :The museum was formally founded on 10 June 1793, during the French Revolution...
in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
. In 1800 the collection was reported by Georges Cuvier
Georges Cuvier
Georges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
who combined the material with that from the collection of Dicquemare, also obtained by the Paris museum.
In 1808, Cuvier scientifically described the theropod vertebrae as the first dinosaur remains ever. However, he considered them to be crocodilian and associated them with fossils of the Teleosauridae
Teleosauridae
The teleosaurids were marine crocodyliforms similar to the modern gharial that lived from the Early Jurassic to the Early Cretaceous. They had long snouts, indicative of piscivory and were the closest relatives to the Metriorhynchidae, the Mesozoic crocodilians that returned to the sea and evolved...
and the Metriorhynchidae
Metriorhynchidae
Metriorhynchidae is an extinct family of metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period of Europe, North America and South America. Metriorhynchids are fully aquatic crocodyliforms. Their forelimbs were small and paddle-like, and unlike living crocodilians,...
. In 1822, Cuvier by the work of Henry De La Bèche
Henry De la Beche
Sir Henry Thomas De la Beche FRS was an English geologist and palaeontologist who helped pioneer early geological survey methods.-Biography:...
became aware that these finds were very disparate, stemming from different periods. He abstained from naming them but in 1824 concluded that there were two main types. In 1825 Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire was a French naturalist who established the principle of "unity of composition". He was a colleague of Jean-Baptiste Lamarck and expanded and defended Lamarck's evolutionary theories...
accordingly named two crocodilian skulls as the genus Steneosaurus
Steneosaurus
Steneosaurus is an extinct genus of teleosaurid crocodyliform from the Early Jurassic to Early Cretaceous . Fossil specimens have been found in England, France, Germany, Switzerland and Morocco.-Species:...
, the one, specimen MNHN 8900, becoming Steneosaurus rostromajor, the other, MNHN 8902, S. rostrominor.
In 1832 however, the German paleontologist Christian Erich Hermann von Meyer
Christian Erich Hermann von Meyer
Christian Erich Hermann von Meyer was a German palaeontologist.He was born at Frankfurt am Main.In 1832 von Meyer issued a work entitled Palaeologica, and in course of time he published a series of memoirs on various fossil organic remains: molluscs, crustaceans, fishes and higher vertebrata,...
split the material. Steneosaurus rostrominor was renamed Metriorhynchus
Metriorhynchus
Metriorhynchus is an extinct genus of marine crocodyliform that lived in the oceans during the Middle to Late Jurassic. Metriorhynchus was named by the German palaeontologist Christian von Meyer in 1830. Metriorhynchus was a carnivore that spent much, if not all, its life out at sea...
geoffroyii while Steneosaurus rostromajor became Streptospondylus altdorfensis. To the last species the theropod remains were referred. The generic name is derived from Greek στρεπτος/streptos, "reversed", and σπονδυλος/spondylos, "vertebra", alluding to the fact that the vertebrae differed from typical crocodile elements in being opisthocoel: convex in front and concave behind. The specific name refers to Altdorf
Altdorf
Altdorf may refer to: In Switzerland:*Altdorf, Switzerland, the capital of the canton of Uri , *Altdorf, Schaffhausen, a village in the canton of Schaffhausen ,...
where also some teleosaurid remains had been found. Von Meyer's name was the first binomial name (also) referring to a theropod.
In 1842 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...
pointed out that von Meyer had been incorrect in changing the original specific name and created the correct combination Streptospondylus rostromajor for Streptospondylus altdorfensis. At the same time he created a second species: Streptospondylus cuvieri based on a single damaged vertebra from the Bathonian
Bathonian
In the geologic timescale the Bathonian is an age or stage of the Middle Jurassic. It lasted from approximately 167.7 Ma to around 164.7 Ma...
, found near Chipping Norton
Chipping Norton
Chipping Norton is a market town in the Cotswold Hills in the West Oxfordshire district of Oxfordshire, England, about southwest of Banbury.-History until the 17th century:...
. In 1861, Owen would refer the entire Cuvier material to S. cuvieri, despite the fact that if it were cospecific the name S. rostromajor would have priority. From that time S. cuvieri was generally accepted in the literature as the valid name, though some workers split off the theropod remains from the crocodilian bones, Edward Drinker Cope
Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
in 1867 naming a Laelaps
Laelaps
The name Laelaps is a name attributed to the following:*Laelaps was a Greek mythological dog who never failed to catch what he was hunting.*Laelaps is a genus of mites which are ectoparasites of rodents...
gallicus and Friedrich von Huene
Friedrich von Huene
Friedrich von Huene was a German paleontologist who named more dinosaurs in the early 20th century than anyone else in Europe.-Biography:...
in 1909 a Megalosaurus
Megalosaurus
Megalosaurus is a genus of large meat-eating theropod dinosaurs of the Middle Jurassic period of Europe...
cuvieri.
In 1964, Alick Donald Walker discovered Owen's mistake, referring the entire theropod material to the new species Eustreptospondylus
Eustreptospondylus
Eustreptospondylus is a genus of megalosaurid dinosaur, from the Callovian stage of the Middle Jurassic period in southern England, at a time when Europe was a series of scattered islands Eustreptospondylus ("well-curved vertebra", in reference to the arrangement of the spine in the original...
divesensis which, however, had a skull not belonging to the Cuvier material as the type specimen, MNHN 1920-7. In 1977 Philippe Tacquet created the genus Piveteausaurus
Piveteausaurus
Piveteausaurus is a genus of theropod dinosaur known from a partial skull discovered in the Middle Jurassic Marnes de Dives formation of Calvados, in northern France.-History and description:...
for this species.
In 2001, Ronan Allain concluded that no connection could be proven between Piveteausaurus and the referred other theropod material from Normandy
Normandy
Normandy is a geographical region corresponding to the former Duchy of Normandy. It is in France.The continental territory covers 30,627 km² and forms the preponderant part of Normandy and roughly 5% of the territory of France. It is divided for administrative purposes into two régions:...
. He also pointed out that the skull von Meyer had based Streptospondylus altdorfensis on was in fact a composite of bones from two species, since named Steneosaurus edwardsi Deslongchamps 1866 and Metriorynchus superciliosum Blainville 1853. Never a lectotype
Lectotype
In botanical nomenclature and zoological nomenclature, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype...
had been chosen from one of the composite parts to give the name Streptospondylus priority over either one of these species. Allain used this situation to remove all the crocodilian material from the Streptospondylus type by designating the complete theropod material as the lectotype. As Steneosaurus rostromajor had been based on the composite skull, the epithet rostromajor now no longer had priority over altdorfensis. This way in 2001 Streptospondylus altdorfensis became the valid name and 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...
of a theropod. Laelaps gallicus and Megalosaurus cuvieri are its objective junior synonyms.
The lectotype specimens, MNHN 8605-09, 8787-89, 8793-94, 8907, were probably found at the coast in layers of the Falaises des Vaches Noires near Calvados
Calvados
The French department of Calvados is part of the region of Basse-Normandie in Normandy. It takes its name from a cluster of rocks off the English Channel coast...
, dating from the late Callovian
Callovian
In the geologic timescale, the Callovian is an age or stage in the Middle Jurassic, lasting between 164.7 ± 4.0 Ma and 161.2 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian....
or early Oxfordian
Oxfordian
Oxfordian may refer to:* Oxfordian theory of Shakespeare authorship, view that Edward de Vere wrote under Shakespeare's name* Oxfordian , a geological time interval...
, about 161 million years old. They consist of several vertebrae series, single vertebrae, a partial left pubis
Pubis
Pubis may refer to:* Pubis * Mons pubis, a padding of fat that protects the pubis bone...
and limb elements. The longest vertebra has a length of 97 millimetres, indicating a total body length of about seven metres. Also a partial left femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
, MNHN 9645, has been referred. Streptospondylus has been diagnosed by several osteological details, among which the possession of two hypapophyses on the, ventrally flat, anterior dorsal vertebrae and the particular connection between the astragalus
Astragalus
Astragalus is a large genus of about 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae, subfamily Faboideae. The genus is native to temperate regions of the Northern Hemisphere...
and the tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
, without a posterior astragalar process but with a distinctive buttress on the tibia above the anterior process.
Owen also named four other species: S. major (1842), S. recentior, S. meyeri (both 1851), and S. grandis (1854), which however are probably based on Iguanodon
Iguanodon
Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...
material. His S. cuvieri, of which the type specimen is lost, is today considered a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
.
In 2010 Gregory S. Paul
Gregory S. Paul
Gregory Scott Paul is a freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal...
renamed (as an informal name) Magnosaurus
Magnosaurus
Magnosaurus was a genus of basal tetanuran theropod dinosaur from the Middle Jurassic of England. It is based on fragmentary remains and has often been confused with or included in Megalosaurus.-History and taxonomy:...
into Streptospondylus nethercombensis.
Phylogeny
Earlier assigned to crocodilian groups, Streptospondylus was in the 20th century typically classified in the Megalosauridae.Recent analyses indicate that Streptospondylus is a tetanuran
Tetanurae
Tetanurae, or "stiff tails", is a clade that includes most theropod dinosaurs, as well as birds. Tetanurans first appear during the early or middle Jurassic Period.-Definition:...
theropod. Allain in 2001 suggested that it was closely related to Eustreptospondylus in the Spinosauroidea. Roger Benson in 2008 and 2010 concluded that whether it is a megalosauroid
Megalosauroidea
Megalosauroidea is a group of tetanuran theropod dinosaurs that lived from the Middle Jurassic to the Late Cretaceous period.-Classification:...
, allosauroid
Allosauroidea
Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Sinraptoridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae...
, or a more primitive form cannot be determined because of its extremely fragmentary remains. Later cladistic analysis by Benson and colleagues from 2010 indicated that Streptospondylus was the sister species of Magnosaurus
Magnosaurus
Magnosaurus was a genus of basal tetanuran theropod dinosaur from the Middle Jurassic of England. It is based on fragmentary remains and has often been confused with or included in Megalosaurus.-History and taxonomy:...
within the Megalosauridae.