Thecocoelurus
Encyclopedia
Thecocoelurus is a genus
of theropod dinosaur
from the early Cretaceous
period of England
.
Thecocoelurus is known only from half of a single cervical
vertebra, discovered by the Rev. William Darwin Fox
on the Isle of Wight
during the 19th century. After his death the Fox Collection was acquired by the British Museum of Natural History. William Davies
was the first to notice the specimen and assumed a close affinity with Coelurus
. It was described by Harry Govier Seeley in 1888. Seeley named the fossil Thecospondylus
Daviesi, referring it to a genus he had named earlier for the incomplete cast of a sacrum
. However, in 1901 Baron Franz Nopcsa renamed it Coelurus daviesi.
In 1923 Friedrich von Huene
decided that it should be removed from either Thecospondylus or Coelurus and given its own genus, Thecocoelurus. The generic name is a contraction of "Thecospondylus" and "Coelurus".
The holotype
, BMNH R181, was found in debris from a layer of the Wessex Formation
, dating from the Barremian
. It consists of the anterior end, about a third, of a cervical vertebra estimated by Seeley to have been nine centimetres long.
Von Huene originally assigned Thecocoelurus to the Coeluridae
, but in 1926 speculated that due to the not inconsiderable size and typical structure of the vertebra it might belong to a member of the Ornithomimidae. Though it has been since been typically identified as an indeterminate "coelurian" theropod, Thecocoelurus was reidentified by Darren Naish
and colleagues in 2001 as a member of the Oviraptorosauria
, a group of omnivorous
maniraptora
n theropods, which would make it the only oviraptorosaur fossil that has ever been found in Europe
. Numerous detailed similarities are shared by the specimen and the cervical vertebrae of caenagnathid oviraptorosaurs. Naish e.a. also considered Thecocoelurus to be a nomen dubium
. In 2004 it was theorized by James Kirkland
that Thecocoelurus might not be an oviraptorosaur, but a member of the therizinosaur
lineage instead, closely related to Falcarius
, again a unique occurrence for Europe.
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...
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...
period 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...
.
Thecocoelurus is known only from half of a single cervical
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
vertebra, discovered by the Rev. William Darwin Fox
William Darwin Fox
The Reverend William Darwin Fox was an English clergyman, naturalist, and a 2nd cousin of Charles Robert Darwin.- Early life :...
on the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
during the 19th century. After his death the Fox Collection was acquired by the British Museum of Natural History. William Davies
William Davies
-Politicians:*William Davies , Georgia-based politician and lawyer*William Davies , British Member of Parliament for Pembrokeshire, 1880–1892*William T...
was the first to notice the specimen and assumed a close affinity with Coelurus
Coelurus
Coelurus is a genus of coelurosaur dinosaur from the Late Jurassic period . The name means "hollow tail", referring to its hollow tail vertebrae...
. It was described by Harry Govier Seeley in 1888. Seeley named the fossil Thecospondylus
Thecospondylus
Thecospondylus is a dubious genus of dinosaur from the Early Cretaceous of EnglandDr. A.C. Horner, an amateur geologist living at Tonbridge, in the nineteenth century acquired a fossil found in the quarry of Southborough...
Daviesi, referring it to a genus he had named earlier for the incomplete cast of a sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
. However, in 1901 Baron Franz Nopcsa renamed it Coelurus daviesi.
In 1923 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:...
decided that it should be removed from either Thecospondylus or Coelurus and given its own genus, Thecocoelurus. The generic name is a contraction of "Thecospondylus" and "Coelurus".
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 R181, was found in debris from a layer of the Wessex Formation
Wessex Formation
The Wessex Formation is an English fossil site and geological formation that dates to the Barremian stage of the Early Cretaceous. It is part of the Wealden Group and underlies the younger Vectis Formation.-Invertebrates:...
, dating from 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...
. It consists of the anterior end, about a third, of a cervical vertebra estimated by Seeley to have been nine centimetres long.
Von Huene originally assigned Thecocoelurus to the Coeluridae
Coeluridae
Coeluridae is a historically polyphyletic family of generally small, carnivorous dinosaurs from the late Jurassic Period...
, but in 1926 speculated that due to the not inconsiderable size and typical structure of the vertebra it might belong to a member of the Ornithomimidae. Though it has been since been typically identified as an indeterminate "coelurian" theropod, Thecocoelurus was reidentified by Darren Naish
Darren Naish
Darren Naish is a vertebrate palaeontologist and science writer. He obtained a geology degree at the University of Southampton and later studied vertebrate palaeontology under British palaeontologist David Martill at the University of Portsmouth, where he obtained both an M. Phil...
and colleagues in 2001 as a member of the Oviraptorosauria
Oviraptorosauria
Oviraptorosaurs are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot - like skulls, with or without bony crests atop the head...
, a group of omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
maniraptora
Maniraptora
Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the dinosaurs that were more closely related to them than to Ornithomimus velox. It contains the major subgroups Avialae, Deinonychosauria, Oviraptorosauria and Therizinosauria. Ornitholestes and the Alvarezsauroidea...
n theropods, which would make it the only oviraptorosaur fossil that has ever been found in 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...
. Numerous detailed similarities are shared by the specimen and the cervical vertebrae of caenagnathid oviraptorosaurs. Naish e.a. also considered Thecocoelurus to be a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
. In 2004 it was theorized by James Kirkland
James Kirkland
James Ian Kirkland is an American paleontologist and geologist. He has worked with dinosaur remains from the south west United States of America and Mexico and has been responsible for discovering new and important genera...
that Thecocoelurus might not be an oviraptorosaur, but a member of the therizinosaur
Therizinosaur
Therizinosaurs are theropod dinosaurs belonging to the clade Therizinosauria. Therizinosaur fossils have been found in Early through Late Cretaceous deposits in Mongolia, the People's Republic of China and Western North America...
lineage instead, closely related to Falcarius
Falcarius
Falcarius is a genus of therizinosaurian dinosaur found in east-central Utah, United States. Its name is derived from the word sickle , which scientists have used to describe its unwieldy clawed hands...
, again a unique occurrence for Europe.