Macrurosaurus
Encyclopedia
Macrurosaurus is the name given to a genus
of dinosaur
from the Early Cretaceous
. It was a titanosauriform which lived in what is now Europe
.
The genus Macrurosaurus was named by Harry Govier Seeley in 1869 but not yet described so that it remained a nomen nudum
. In 1876 Seeley described the type species
, Macrurosaurus semnus, making the name valid. No other species are known. The generic name is derived from Greek makros, "large", and oura, "tail". The specific name is derived from Greek semnos, "stately" or "impressive".
The holotype
of Macrurosaurus, SM B55630, consists of two series of caudal vertebrae found around 1864 near Cambridge, England in the Cambridge Greensand
, strata themselves deposited during the Aptian
but containing reworked fossil material dating perhaps from around 130 million years ago, the Barremian
. The first was acquired by the Woodwardian Museum from William Farren who had it dug up at Coldhams Common. This series is made up of 25 proximal vertebrae. The second was found by Reverend W. Stokes-Shaw at a slightly more western location near Barton
. It contained fifteen smaller distal vertebrae, from the tail end. Seeley, acting on the presumption that both finds belonged to the same species if not individual, combined the two series into one tail of about 4.5 metres length.
Other fragmentary fossils from England
(Acanthopholis
platypus), France
and Argentina
have later been referred to Macrurosaurus but the identity is today doubted.
Macrurosaurus was by Seeley himself estimated to be about ten metres long. Often a length of around twelve metres (40 ft) is indicated in the popular literature. The vertebrae in front are procoelous, meaning that the vertebral centra are hollow at the front end and convex at the back. Those behind are amphicoelous: hollow at both ends. Seeley assumed that the full count of tail vertebrae would have been about fifty.
Macrurosaurus was by Seeley assigned to the Dinosauria. Richard Lydekker
in 1888 understood it belonged to the Sauropoda
. In 1929 Friedrich von Huene
referred it to the Titanosauridae. In recent years however, it has been commonly concluded that the species cannot be further determined than a more general Titanosauriformes. Also it is today often seen as a nomen dubium
.
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 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...
from the Early 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...
. It was a titanosauriform which lived in what is now 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...
.
The genus Macrurosaurus was named by Harry Govier Seeley in 1869 but not yet described so that it remained a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
. In 1876 Seeley described 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...
, Macrurosaurus semnus, making the name valid. No other species are known. The generic name is derived from Greek makros, "large", and oura, "tail". The specific name is derived from Greek semnos, "stately" or "impressive".
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...
of Macrurosaurus, SM B55630, consists of two series of caudal vertebrae found around 1864 near Cambridge, England in 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:...
, strata themselves deposited during 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...
but containing reworked fossil material dating perhaps from around 130 million years ago, the Barremian
Barremian
The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...
. The first was acquired by the Woodwardian Museum from William Farren who had it dug up at Coldhams Common. This series is made up of 25 proximal vertebrae. The second was found by Reverend W. Stokes-Shaw at a slightly more western location near Barton
Barton, Cambridgeshire
Barton is a village and civil parish in the South Cambridgeshire district of Cambridgeshire, England. It is about south-west of Cambridge, near junction 12 of the M11 motorway.- History :...
. It contained fifteen smaller distal vertebrae, from the tail end. Seeley, acting on the presumption that both finds belonged to the same species if not individual, combined the two series into one tail of about 4.5 metres length.
Other fragmentary fossils from 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...
(Acanthopholis
Acanthopholis
Acanthopholis is a genus of ankylosaurian dinosaur in the family Nodosauridae that lived during the Early Cretaceous Period of England....
platypus), 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...
and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
have later been referred to Macrurosaurus but the identity is today doubted.
Macrurosaurus was by Seeley himself estimated to be about ten metres long. Often a length of around twelve metres (40 ft) is indicated in the popular literature. The vertebrae in front are procoelous, meaning that the vertebral centra are hollow at the front end and convex at the back. Those behind are amphicoelous: hollow at both ends. Seeley assumed that the full count of tail vertebrae would have been about fifty.
Macrurosaurus was by Seeley assigned to the Dinosauria. Richard Lydekker
Richard Lydekker
Richard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.-Biography:...
in 1888 understood it belonged to the Sauropoda
Sauropoda
Sauropoda , or the sauropods , are an infraorder of saurischian dinosaurs. They had long necks, long tails, small heads , and thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land...
. In 1929 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:...
referred it to the Titanosauridae. In recent years however, it has been commonly concluded that the species cannot be further determined than a more general Titanosauriformes. Also it is today often seen as a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
.