Sarcosaurus
Encyclopedia
Sarcosaurus is a genus
of theropod dinosaur
, either a coelophysoid or a basal ceratosaur, roughly 3.5 meters long. It lived during the Sinemurian
stage of the Early Jurassic
, about 194 million years ago.
Fossil
s of Sarcosaurus were found in the Lower Lias of England
. The type species
, Sarcosaurus woodi, was first described by Charles William Andrews
in 1921 shortly after a partial skeleton had been found by S.L. Wood near Barrow-on-Soar. The generic name is derived from Greek sarx, "flesh". The specific name honours Wood. The holotype
, BMNH 4840/1, consists of a pelvis
, a vertebra and the upper part of a femur
. The preserved length of the femur is 31.5 centimetres.
A second species, Sarcosaurus andrewsi, was named by Friedrich von Huene
in 1932, based on a 445 millimetres long tibia
, BMNH R3542, described by Arthur Smith Woodward
in 1908 and found near Wilmcote
. Confusingly von Huene in the same publication named the very same fossil Magnosaurus
woodwardi. Later he made a choice for S. andrewsi to be the valid name. In 1974 S. andrewsi was reclassified as Megalosaurus
andrewsi by Michael Waldman
, on the probably erroneous assumption it was a megalosaurid
. A later study concluded the two species to be indistinguishable except for size, but other authors consider any identity to be unprovable as there are no comparable remains and conclude both species to lack autapomorphies
and therefore to be nomina dubia
.
Von Huene in 1932 referred a partial skeleton from the collection of the Warwick Museum to S. woodi but the identity is unproven; in 1995 it was given the generic name "Liassaurus
" but this has remained a nomen nudum
.
Andrews originally assigned Sarcosaurus to the Megalosauridae. The first to suggest a more basal position was Samuel Paul Welles
who placed it in the Coelophysidae
. Later analyses resulted in either a position in the Ceratosauria
, or in the Coelophysoidea
.
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 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...
, either a coelophysoid or a basal ceratosaur, roughly 3.5 meters long. It lived during the Sinemurian
Sinemurian
In the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...
stage of the Early Jurassic
Early Jurassic
The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...
, about 194 million years ago.
Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of Sarcosaurus were found in the Lower Lias 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...
. 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...
, Sarcosaurus woodi, was first described by Charles William Andrews
Charles William Andrews
Charles William Andrews F.R.S., was a British palaeontologist whose career as a vertebrate paleontologist, both as a curator and in the field, was spent in the services of the British Museum, Department of Geology.-Biography:...
in 1921 shortly after a partial skeleton had been found by S.L. Wood near Barrow-on-Soar. The generic name is derived from Greek sarx, "flesh". The specific name honours Wood. The 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 4840/1, consists of a pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
, a vertebra and the upper part of a 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...
. The preserved length of the femur is 31.5 centimetres.
A second species, Sarcosaurus andrewsi, was named by 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 1932, based on a 445 millimetres long 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....
, BMNH R3542, described by Arthur Smith Woodward
Arthur Smith Woodward
Sir Arthur Smith Woodward was an English palaeontologist.-Biography:Woodward was born in Macclesfield, Cheshire, England and was educated there and at Owens College, Manchester. He joined the staff of the Department of Geology at the Natural History Museum in 1882. He became assistant Keeper of...
in 1908 and found near Wilmcote
Wilmcote
Wilmcote is a village and since 2004 a separate civil parish in the English county of Warwickshire, about north of Stratford-upon-Avon. Prior to 2004, it was part of the same parish as Aston Cantlow and the 2001 population for the whole being 1,674....
. Confusingly von Huene in the same publication named the very same fossil 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:...
woodwardi. Later he made a choice for S. andrewsi to be the valid name. In 1974 S. andrewsi was reclassified as Megalosaurus
Megalosaurus
Megalosaurus is a genus of large meat-eating theropod dinosaurs of the Middle Jurassic period of Europe...
andrewsi by Michael Waldman
Michael Waldman
Michael Waldman is executive director of the Brennan Center for Justice at NYU School of Law, a nonpartisan law and policy institute that focuses on fundamental issues of democracy and justice. The Center is one of the nation’s leading legal voices on election law, Constitutional law, government...
, on the probably erroneous assumption it was a megalosaurid
Megalosaurid
Megalosauridae was a family of relatively primitive tetanuran theropod dinosaurs, order Saurischia. They were small-to-large carnivores with sharp teeth and three claws on each hand. Some members of this group were Megalosaurus, Eustreptospondylus, Streptospondylus and Torvosaurus...
. A later study concluded the two species to be indistinguishable except for size, but other authors consider any identity to be unprovable as there are no comparable remains and conclude both species to lack autapomorphies
Autapomorphy
In cladistics, an autapomorphy is a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group...
and therefore to be nomina dubia
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
.
Von Huene in 1932 referred a partial skeleton from the collection of the Warwick Museum to S. woodi but the identity is unproven; in 1995 it was given the generic name "Liassaurus
Liassaurus
"Liassaurus" is the informal name given to an as yet undescribed genus of dinosaur from the Early Jurassic. It was a probable ceratosaur which lived in what is now Europe. The type species, "L. huenei", was coined by Welles, H.P...
" but this has remained a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
.
Andrews originally assigned Sarcosaurus to the Megalosauridae. The first to suggest a more basal position was Samuel Paul Welles
Samuel Paul Welles
Samuel Paul Welles was an American palaeontologist, who was Research Associate at the Museum of Palaeontology, University of California, Berkeley. He took part in excavations at the 'Placerias Quarry' in 1930 and the Shonisaurus discoveries of 1954 and later, in what is now the Berlin-Ichthyosaur...
who placed it in the Coelophysidae
Coelophysidae
The Coelophysidae are a family of primitive carnivorous theropod dinosaurs. Most species were relatively small in size. The family flourished in the Late Triassic and Early Jurassic periods....
. Later analyses resulted in either a position in the Ceratosauria
Ceratosauria
Ceratosaurs are members of a group of theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. There is presently no universally agreed upon listing of species or diagnostic characters of Ceratosauria, though they were less derived...
, or in the Coelophysoidea
Coelophysoidea
Coelophysoids were common dinosaurs of the Late Triassic and Early Jurassic periods. They were widespread geographically, probably living on all continents. Coelophysoids were all slender, carnivorous forms with a superficial similarity to the coelurosaurs, with which they were formerly...
.
External links
- Sarcosaurus in The Dinosaur Encyclopaedia at Dino Russ's Lair
- Sarcosaurus in the Dino Directory