Mantellisaurus

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Mantellisaurus
Temporal range: Early Cretaceous, Aptian 125 Ma
Isle of Wight Mantellisaurus.jpg
Holotype skeleton, Natural History Museum, London
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Suborder: Ornithopoda
Superfamily: Hadrosauroidea
Genus: Mantellisaurus
Paul, 2007
Species:
M. atherfieldensis
Binomial name
Mantellisaurus atherfieldensis
Hooley, 1925
Synonyms

Mantellisaurus is a genus of iguanodontian dinosaur that lived in the Barremian and early Aptian ages of the Early Cretaceous Period of Europe. Its remains are known from Belgium (Bernissart), England and possibly Germany. Formerly known as Iguanodon atherfieldensis, the new genus Mantellisaurus was erected by Gregory Paul in 2007. According to Paul, it was more lightly built than Iguanodon and more closely related to Ouranosaurus, making Iguanodon in its traditional sense paraphyletic. It is known from many complete and almost complete skeletons. The genus name honours Gideon Mantell, the discoverer of Iguanodon.

Description[edit]

Restoration based on the holotype specimen, NHMUK R5764.

Mantellisaurus was a lightly constructed iguanodont. Compared to Iguanodon bernissartensis, Mantellisaurus was smaller, estimated at 750 kilograms (1,650 lb) in weight. Its forelimbs were proportionally shorter than those of I. bernissartensis. In Mantellisaurus the forelimbs were about half the length of the hindlimbs whereas they were about 70 percent the length of the hindlimbs in I. bernissartensis. Due to the short length of its forelimbs and the shortness of its body, Paul proposed that it was primarily bipedal, only going on all fours when standing still or moving slowly.[1]

Discovery[edit]

Drawing of the holotype skull from Hooley's original description

The holotype fossil, NHMUK R5764, was originally discovered by Reginald Walter Hooley in 1914 in the upper Vectis Formation of southern England and reported upon in 1917. He posthumously named it Iguanodon atherfieldensis in 1925. Atherfield is the name of a village on the southwest shore of the Isle of Wight where the fossil was found. Synonyms include Dollodon and possibly Proplanicoxa.[2]

Specimen IRSNB 1551[edit]

Restoration based on specimen IRSNB 1551

Specimen IRSNB 1551 from the Sainte-Barbe Clays, Belgium, became the second mounted skeleton of a non-avian dinosaur made primarily out of actual bone when put on display by Louis Dollo in 1884. This specimen was originally assigned to Iguanodon mantelli by George Albert Boulenger in 1881, but was in 1986 thought to pertain to Iguanodon atherfieldensis by David Bruce Norman. The specimen was assigned to its own genus and species, Dollodon bampingi, by Gregory S. Paul in 2008. The genus was named after Dollo, who first described the remains, and the specific name was in honour of popular science writer Daniel Bamping, who assisted Paul in his investigations.

One of the first-ever mounted dinosaur specimens (IRSNB 1551), Royal Belgian Institute of Natural Sciences

Paul noted several differences between the Mantellisaurus type (NHMUK R5764) and IRSNB 1551. The Mantellisaurus type had proportionally shorter forelimbs with a larger pelvis and he argued it was probably more bipedal, whereas IRSNB 1551 was more likely to be quadrupedal. Paul also noted that the snout and trunk of IRSNB 1551 were proportionally longer than the Mantellisaurus type specimen.[1]

The validity of Dollodon has since been disputed. In 2010, Kenneth Carpenter and Yusuke Ishida synonymized Dollodon bampingi with Iguanodon seelyi, a species based on BMNH R 28685 from Wessex Formation, England.[3] Likewise, David B. Norman and Andrew McDonald do not consider Dollodon a valid genus or species and instead include it with Mantellisaurus.[4][5][6]

Classification[edit]

The cladogram below follows an analysis by Andrew McDonald, 2012.[7]

Styracosterna

Uteodon aphanoecetes

Hippodraco scutodens

Theiophytalia kerri

Iguanacolossus fortis

Lanzhousaurus magnidens

Kukufeldia tilgatensis

Barilium dawsoni

Hadrosauriformes

Iguanodon bernissartensis

Hadrosauroidea

Mantellisaurus atherfieldensis

Other hadrosauroids

References[edit]

  1. ^ a b Paul, Gregory S. (2008). "A revised taxonomy of the iguanodont dinosaur genera and species". Cretaceous Research. 29 (2): 192–216. doi:10.1016/j.cretres.2007.04.009.
  2. ^ McDonald, Andrew T. (2012). "The status of Dollodon and other basal iguanodonts (Dinosauria: Ornithischia) from the upper Wealden beds (Lower Cretaceous) of Europe". Cretaceous Research. 33: 1–6. doi:10.1016/j.cretres.2011.03.002.
  3. ^ Carpenter, K. & Ishida, Y. (2010). "Early and "Middle" Cretaceous Iguanodonts in Time and Space" (PDF). Journal of Iberian Geology. 36 (2): 145–164. doi:10.5209/rev_JIGE.2010.v36.n2.3.[permanent dead link]
  4. ^ Norman, David. (2010). "A taxonomy of iguanodontian (Dinosauria: Ornithopoda) from the lower Wealden Group (Cretaceous: Valanginian) of southern England" (PDF). Zootaxa. 2489: 47–66.
  5. ^ McDonald, Andrew T. (2012). "The status of Dollodon and other basal iguanodonts (Dinosauria: Ornithischia) from the upper Wealden beds (Lower Cretaceous) of Europe". Cretaceous Research. 33: 1–6. doi:10.1016/j.cretres.2011.03.002.
  6. ^ Norman, D.B., 2012, "Iguanodontian Taxa (Dinosauria: Ornithischia) from the Lower Cretaceous of England and Belgium". In: Pascal Godefroit (ed.), Bernissart Dinosaurs and Early Cretaceous Terrestrial Ecosystems. Indiana University Press. 464 pp. http://www.iupress.indiana.edu/product_info.php?products_id=800408
  7. ^ McDonald, A. T. (2012). Farke, Andrew A, ed. "Phylogeny of Basal Iguanodonts (Dinosauria: Ornithischia): An Update". PLoS ONE. 7 (5): e36745. doi:10.1371/journal.pone.0036745. PMC 3358318. PMID 22629328.
  • Cornuel, M., 1850, Note sur des ossements fossiles decouvertes dans le calcaire neocomien de Wassy (Haute-Marne): Bulletin de la societie geologiques de France, 2nd series, v. 7, p. 702-704.
  • Hooley, W., 1925, On the skeleton of Iguanodon atherfieldensis sp. nov., from the Wealden Shales of Atherfield (Isle of Wight): Quarterly Journal of the Geological Society of London, v. 81, p. 1-61.
  • Hulke, J. W., 1879, Vectisaurus valdensis, a new Wealden Dinosaur: Quarterly Journal of the Geological Society of London, v. 35, p. 421-424.
  • Owen, R., 1842, Report on British Fossil Reptiles. Part II: Report of the British Association for the Advancement of Science, v. 11, p. 60-204.
  • Lydekker, R., 1888, Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History), Cromwell Road, S.W., Part 1. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamta, Rhynchocephalia, and Proterosauria: British Museum of Natural History, London, 309pp.
  • Norman, D.B., 2012. "Iguanodontian Taxa (Dinosauria: Ornithischia) from the Lower Cretaceous of England and Belgium". In: Pascal Godefroit (ed.), Bernissart Dinosaurs and Early Cretaceous Terrestrial Ecosystems. Indiana University Press. 464 pp. http://www.iupress.indiana.edu/product_info.php?products_id=800408
  • Paul, G.S. 2007. Turning the old into the new: a separate genus for the gracile iguanodont from the Wealden of England; pp. 69–77 in K. Carpenter (ed.), Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Indiana University Press, Bloomington.