Calamosaurus

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Calamosaurus
Temporal range: Barremian, 129–125  Ma
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Calamosaurus.jpg
Cervical vertebra of Calamosaurus foxi
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Compsognathidae
Genus: Calamosaurus
Lydekker, 1891
Species:
C. foxi
Binomial name
Calamosaurus foxi
(Lydekker, 1889 [originally Calamospondylus ])
Synonyms

Calamosaurus (meaning "reed lizard") 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 (BMNH R901), collected by Reverend William Fox.

Contents

History and taxonomy

Illustration of the vertebra Calamosaurus vertebra.jpg
Illustration of the vertebra

Richard Lydekker came across these bones when cataloguing the Fox collection and named them Calamospondylus foxi, noting their similarity to those of Coelurus . [1] Unfortunately, Calamospondylus had already been coined in 1866 (ironically by Reverend Fox himself, the very man honored in Lydekker's species name). [2] Lydekker renamed it in 1891 to its present title. [3] He also at this time provisionally referred to it the right tibia NHMUK R.186, which was discovered by William D. Fox in 1865 or 1866 and was identified by Naish et al. (2001) as belonging to a basal coelurosaurian like a compsognathid, and has recently been referred to Ornithomimosauria by Allain et al. (2014). [4] [5] NHMUK R.186 has since been moved to Calamospondylus .

Because of its sparse remains, it has received little attention. Often, it has been synonymized with Calamospondylus as part of a long, confusing taxonomic tangle, [6] [7] [8] although there is no comparable material between the two genera. [4] Modern reviews have regarded it as a dubious theropod, [9] [10] although potentially a valid coelurosaurian. [4]

In 2002 Paul Turner found a dorsal vertebra near Grange Chine on the Isle of Wight. An associated partial tibia and metatarsal fragment were subsequently discovered by Oliver Mattsson and referred to Calamosaurus. [11] Another specimen referred to Calamosaurus was collected by local fossil hunter Kai Bailey in 2014. Both specimens are on display at the Dinosaur Expeditions, Conservation and Palaeoart Centre near Brighstone, Isle of Wight.

A neck vertebra of a Calamosaurus was found near Chilton Chine on the Isle of Wight by local fossil hunter Dave Badman. The newly discovered vertebra has gone on display at the Dinosaur Isle Museum in Sandown, Isle of Wight.

Specimen NHMUK R.186

NHMUK R.186 was discovered by William D. Fox in 1865 or 1866 and was first assigned to Hypsilophodon foxii by Lydekker (1888). [12] Lydekker (1891) moved NHMUK R.186 to Aristosuchus pusillis , [13] and Galton (1973) agreed with this classification. [14] Welles & Long (1974) referred it to the Ornithomimidae, [15] while Norman (1990), Kirkland et al. (1998) and Long and Molnar (1998) referred NHMUK R.186 to Coelurosauria. [16] [17] [18] Galton and Molnar (2005) noted the similarities of NHMUK R.186 to the holotype of Coelurus fragilis , [19] and Allain et al. (2014) agreed with the placement of NHMUK R.186 within Coelurosauria. [20]

Naish et al. (2001) tentatively referred the tibia to Calamosaurus foxi, [21] and NHMUK R.186 has since been moved to Calamospondylus oweni . [22]

Paleobiology

As a possible basal coelurosaur, Calamosaurus would have been a small, agile, bipedal carnivore. Naish et al. (2001) estimate the living animal would have been around 3–5 meters (9.8–16.4 ft) long, with a small head given the build of the neck vertebrae. [4]

Related Research Articles

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.

<i>Valdosaurus</i> Extinct genus of dinosaurs

Valdosaurus is a genus of bipedal herbivorous iguanodont ornithopod dinosaur found on the Isle of Wight and elsewhere in England, Spain and possibly also Romania. It lived during the Early Cretaceous.

<i>Neovenator</i> Extinct genus of dinosaurs

Neovenator is a genus of carcharodontosaurian theropod dinosaur. It is known from several skeletons found in the Early Cretaceous (Hauterivian-Barremian) Wessex Formation on the south coast of the Isle of Wight, southern England. It is one of the best known theropod dinosaurs from the Early Cretaceous of Europe.

<i>Altispinax</i> Genus of dinosaurs (fossil)

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.

<span class="mw-page-title-main">Darren Naish</span> British palaeontologist and science writer (born 1975)

Darren William Naish is a British vertebrate palaeontologist, author and science communicator.

<i>Yaverlandia</i> Extinct genus of dinosaurs

Yaverlandia is a genus of maniraptoran dinosaur. Known from a partial fossil skull found in Lower Cretaceous strata of the Wessex Formation on the Isle of Wight. it was described as the earliest known member of the pachycephalosaurid family, but research by Darren Naish shows it to have actually been a theropod, seemingly a maniraptoran. The type species is Y. bitholus.

<i>Aristosuchus</i> Extinct genus of dinosaurs

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.

<i>Walgettosuchus</i> Extinct genus of dinosaurs

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.

<i>Valdoraptor</i> Extinct genus of dinosaurs

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.

Eucamerotus was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation (Wealden) of the Isle of Wight, England.

<i>Magnosaurus</i> Extinct genus of dinosaurs

Magnosaurus was a genus of theropod dinosaur from the Middle Jurassic of England. It is based on fragmentary remains and has often been confused with or included in Megalosaurus.

<i>Oplosaurus</i> Extinct genus of dinosaurs

Oplosaurus was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is known from a single tooth usually referred to the contemporaneous "wastebasket taxon" Pelorosaurus, although there is no solid evidence for this.

<i>Thecocoelurus</i> Extinct genus of dinosaurs

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.

Orthogoniosaurus was a genus of theropod dinosaur from the late Maastrichtian-age Upper Cretaceous Lameta Formation of Jabalpur, India. It is based on one small, fragmentary tooth.

<i>Ornithodesmus</i> Extinct genus of dinosaurs

Ornithodesmus is a genus of small, dromaeosaurid dinosaur from the Isle of Wight in England, dating to about 125 million years ago. The name was originally assigned to a bird-like sacrum, initially believed to come from a bird and subsequently identified as a pterosaur. More complete pterosaur remains were later assigned to Ornithodesmus, until recently a detailed analysis determined that the original specimen in fact came from a small theropod, specifically a dromaeosaur, making it one of the first dromaeosaurs known to science. All pterosaurian material previously assigned to this genus has been renamed Istiodactylus.

<span class="mw-page-title-main">Wessex Formation</span> Early Cretaceous geological formation in England

The Wessex Formation is a fossil-rich English geological formation that dates from the Berriasian to Barremian stages of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vectis Formation and overlies the Durlston Formation. The dominant lithology of this unit is mudstone with some interbedded sandstones. It is part of the strata of the Wessex Basin, exposed in both the Isle of Purbeck and the Isle of Wight. While the Purbeck sections are largely barren of vertebrate remains, the Isle of Wight sections are well known for producing the richest and most diverse fauna in Early Cretaceous Europe.

The Vectis Formation is a geological formation on the Isle of Wight and Swanage, England whose strata were formed in the lowermost Aptian, approximately 125 million years ago. The environment of deposition was that of a freshwater coastal lagoon with occasional marine influence after the early Aptian marine transgression, transitioning from the floodplain environment of the underlying Wessex Formation. The primary lithology is of laminated grey mudstones. The Vectis Formation is composed of three geological members: the Shepherds Chine member, the Barnes High Sandstone member, and the Cowleaze Chine member. It is overlain by the fully marine Atherfield Clay Formation, part of the Lower Greensand Group. Dinosaur remains are among the fossils that have been recovered from the formation.

<i>Barilium</i> Extinct genus of dinosaurs

Barilium is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon by Richard Lydekker in 1888, the specific epithet honouring the discoverer Charles Dawson, who collected the holotype during the 1880s.

References

  1. Lydekker. R. (1889). On a coelurid dinosaur from the Wealden. Geological Magazine6:119-121.
  2. Fox, W.D. in Anonymous. (1866) Another Wealden reptile. Athenaeum2014:740.
  3. Lydekker. R. (1891). On certain ornithosaurian and dinosaurian remains. Quarterly Journal of the Geological Society of London47:41-44.
  4. 1 2 3 4 Naish, D., Hutt, S., and Martill, D.M. (2001). Saurischian dinosaurs 2: theropods. In: Martill, D.M., and Naish, D. (eds.). Dinosaurs of the Isle of Wight. The Palaeontological Association:London, 242-309. ISBN   0-901702-72-2
  5. R. Allain, R. Vullo, J. Le loeuff & J.-F. Tournepiche (2014) European ornithomimosaurs (Dinosauria, Theropoda): an undetected record. Geologica Acta12: (2) (advance online publication) June 2014.
  6. Swinton, W.E. (1936). The dinosaurs of the Isle of Wight. Proceedings of the Geologists' Association47(3):204-220.
  7. Romer, A.S. (1956). Osteology of the Reptiles. University of Chicago Press:Chicago, 1-772. ISBN   0-89464-985-X
  8. Steel, R. (1970). Part 14. Saurischia. Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology. Part 14. Gustav Fischer Verlag:Stuttgart, 1-87.
  9. Norman, D.B. (1990). Problematic theropoda: "coelurosaurs". In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria. University of California Press:Berkeley, 280-305. ISBN   0-520-06727-4.
  10. Holtz Jr., T.R., Molnar, R.E., and Currie, P.J. (2004). Basal Tetanurae. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (second edition). University of California Press:Berkeley, 71-110. ISBN   0-520-24209-2.
  11. Naish, D. 2011. Theropod dinosaurs. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 526–559.
  12. Lydekker, Richard (1888). Catalogue of the fossil Reptilia and Amphibia in the British Museum (Natural history) ... By Richard Lydekker ... London: Printed by order of the Trustees.
  13. Lydekker, R. (1891). "On certain Ornithosaurian and Dinosaurian Remains". Quarterly Journal of the Geological Society. 47 (1–4): 41–44. doi:10.1144/gsl.jgs.1891.047.01-04.06. ISSN   0370-291X.
  14. Galton, P.M., (1973). A femur of a small theropod dinosaur from the Lower Cretaceous of England. Journal of Paleontology, 47, 996-997.
  15. Welles, S.P., Long, R.A., (1974). The tarsus of theropod dinosaurs. Annals of the South African Museum, 64, 191-218.
  16. Norman, D.B., (1990). Problematic Theropoda: “Coelurosaurs”. In: Weishampel, D.B., Dodson, P., Osmolska, H. (eds.). The Dinosauria. Berkeley, University of California Press, 280-305.
  17. Kirkland, J.I.; Britt, B.B.; Whittle, C.H.; Madsen, S.K.; Burge, D.L. (1998). "A small coelurosaurian theropod from the Yellow Cat Member of the Cedar Mountain Formation (Lower Cretaceous, Barremian) of eastern Utah". New Mexico Museum of Natural History and Science Bulletin. 14: 239–248.
  18. Long, J.A. and Molnar, R.E. (1998). "A new Jurassic theropod dinosaur from Western Australia". Records of the Western Australian Museum 19 (1): 221-229
  19. Galton, P.M., Molnar, R.E., (2005). Tibiae of small theropod dinosaurs from Southern England: from the Middle Jurassic of Stonesfield near Oxford and the Lower Cretaceous of the Isle of Wight. In: Carpenter, K. (ed.). The carnivorous dinosaurs. Bloomington and Indianapolis, Indiana University Press, 3-22
  20. Allain, R.; Vullo, R.; Le Louff, J.; Tournepiche, J-F. (2014). "European ornithomimosaurs (Dinosauria, Theropoda): an undetected record". Geologica Acta (17). doi: 10.1344/105.000002083 . ISSN   1695-6133.
  21. Naish, D., Hutt, S., and Martill, D.M. (2001). Saurischian dinosaurs 2: theropods. In: Martill, D.M., and Naish, D. (eds.). Dinosaurs of the Isle of Wight. The Palaeontological Association:London, 242-309. ISBN   0-901702-72-2
  22. "Down on the (former) Dinosaur Farm". Love in the Time of Chasmosaurs. Retrieved 23 October 2023.