Thecocoelurus | |
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Holotype vertebra | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Clade: | Coelurosauria |
Genus: | † Thecocoelurus Huene, 1923 |
Species: | †T. daviesi |
Binomial name | |
†Thecocoelurus daviesi | |
Synonyms [1] | |
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Thecocoelurus is a dubious genus of theropod dinosaur from the early Cretaceous period of England. The phylogenetic placement of this genus is uncertain, and it has been referred to an oviraptosaur, an ornithomimosaur, or a therizinosaur by different researchers throughout its history.
Thecocoelurus is known only from half of a single cervical vertebra, discovered by the Rev. William 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. [2] However, in 1901 Baron Franz Nopcsa renamed it Coelurus daviesi. [3] 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". [4]
The holotype, NHMUK PV 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. [5] 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 maniraptoran 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 et al. also considered Thecocoelurus to be a nomen dubium . [6] 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 , [7] again a unique occurrence for Europe.
A 2014 re-evaluation comparing the specimens with European ornithomimosaur fossils found that Thecocoelurus was likely one of the oldest known ornithomimosaurs, and a possible senior synonym of Valdoraptor . [1] However, researchers Micky Mortimer and Darren Naish have expressed doubt on its ornithomimosaur affinities, suggesting instead it may represent a therizinosaur similar to Falcarius . [8] [9]
Segnosaurus is a genus of therizinosaurid dinosaur that lived in what is now southeastern Mongolia during the Late Cretaceous, about 102–86 million years ago. Multiple incomplete but well-preserved specimens were discovered in the Gobi Desert in the 1970s, and in 1979 the genus and species Segnosaurus galbinensis were named. The generic name Segnosaurus means "slow lizard" and the specific name galbinensis refers to the Galbin region. The known material of this dinosaur includes the lower jaw, neck and tail vertebrae, the pelvis, shoulder girdle, and limb bones. Parts of the specimens have gone missing or become damaged since they were collected.
Beipiaosaurus is a genus of therizinosauroid theropod dinosaurs that lived in China during the Early Cretaceous in the Yixian Formation. The first remains were found in 1996 and formally described in 1999. Before the discovery of Yutyrannus, Beipiaosaurus were among the heaviest dinosaurs known from direct evidence to be feathered. Beipiaosaurus is known from three reported specimens. Numerous impressions of feather structures were preserved that allowed researchers to determine the feathering color which turned out to be brownish.
The Isle of Wight is one of the richest dinosaur localities in Europe, with over 20 species of dinosaur having been recognised from the early Cretaceous Period, some of which were first identified on the island, as well as the contemporary non-dinosaurian species of crocodile, turtle and pterosaur.
Falcarius is a genus of primitive therizinosaur dinosaur that lived during the Early Cretaceous period in what is now North America. Its remains were first collected in the Cedar Mountain Formation in 1999, with subsequent findings made during the 2000s. The genus is known from multiple specimens ranging from immature to fully-grown individuals.
Therizinosaurs are an extinct group of large herbivorous theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been found in Jurassic deposits of Asia and Europe. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, Therizinosaurus, is derived from the Greek θερίζω and σαῦρος. The older representative, Segnosaurus, is derived from the Latin sēgnis ('slow') and the Greek σαῦρος.
Metriacanthosaurus is a genus of metriacanthosaurid dinosaur from the Kimmeridge Clay Formation and Oxford Clay Formation of England, dating to the Late Jurassic period, about 160 million years ago.
Altispinax is a genus of large predatory theropod dinosaur from the Early Cretaceous period of what is now the Wadhurst Clay Formation of East Sussex, England.
Alxasaurus is a genus of therizinosauroid theropod dinosaurs from the Early Cretaceous Bayin-Gobi Formation of Inner Mongolia.
Eustreptospondylus is a genus of megalosaurid theropod dinosaur, from the Oxfordian stage of the Late Jurassic period in southern England, at a time when Europe was a series of scattered islands.
Darren William Naish is a British vertebrate palaeontologist, author and science communicator.
Aristosuchus is a genus of small coelurosaurian dinosaur whose name was derived from the Greek ἄριστος and σουχος. It shared many characteristics with birds.
Calamospondylus is a genus of theropod dinosaur. It lived during the Early Cretaceous and its fossils were found on the Isle of Wight in southern England. The type species is C. oweni.
Betasuchus is a genus of theropod dinosaur which lived during the Late Cretaceous Period. Betasuchus is, besides Orthomerus, the only dinosaur genus named from remains found in the Netherlands and the only non-avian theropod found in the Maastrichtian Beds.
Calamosaurus was a genus of small theropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is based on two cervical vertebrae, collected by Reverend William Fox.
Walgettosuchus is a dubious or possibly invalid genus of extinct tetanuran theropod dinosaur that lived in Australia during the Late Cretaceous (Cenomanian). It is known from a single caudal vertebra.
Valdoraptor is a genus of theropod dinosaur from the Early Cretaceous. Its fossils were found in England. It is known only from bones of the feet. The holotype, BMNH R2559, was found near Cuckfield in layers of the Tunbridge Wells Sand Formation dating from the late Valanginian. The specimen is damaged lacking parts of the upper and lower ends. It has a conserved length of 215 millimetres (8.5 in) and an estimated length of 240 millimetres (9.4 in). This genus is paleontologically significant for being the first ornithomimosaur specimen known from England and represents the earliest record of ornithomimosaurs.
Thecospondylus is a dubious genus of dinosaur from the Early Cretaceous of England. Scientists are unsure as to whether Thecospondylus was a saurischian or an ornithischian.
Erectopus is an extinct genus of basal allosauroid theropod from the Early Cretaceous La Penthiève Beds Formation of France and also possibly the Cernavodă Formation of southern Romania. The type species is E. superbus, which was initially known as a species of Megalosaurus.
Yurgovuchia is a genus of dromaeosaurid theropod dinosaurs that lived in North America during the Early Cretaceous period in what is now the Cedar Mountain Formation. It contains a single species, Yurgovuchia doellingi. The remains were discovered in Utah, United States.