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''Laplatasaurus'' (meaning "La Plata lizard") is a genus of titanosauran sauropod dinosaur that lived during the Late Cretaceous in South America. The genus was named in 1927 by Friedrich von Huene, but without a description, so that it remained a ''nomen nudum''.〔Huene, F. von, 1927, "Sichtung der Grundlagen der Jetzigen Kenntnis der Sauropoden", ''Eclogae geologicae Helvetiae'', 20: 444-470〕 In 1929 the type species, ''Laplatasaurus aurakanicus'', was described by Huene.〔Huene, F. von, 1929, ''Los Saurisquios y Ornithisquios de Cretaceo Argentino'', Anales Museo de La Plata, 2nd series, v. 3, p. 1-196〕 The generic name refers to La Plata. The specific name is derived from the ''Auracanos'' or Mapuche. By accident Huene in 1929 also mentioned a "Laplatasaurus wichmannianus" but that was a ''lapsus calami'' for ''Antarctosaurus wichmannianus''. In 1933 however, he and Charles Alfred Matley renamed ''Titanosaurus madagascariensis'' to ''Laplatasaurus madagascariensis''.〔Huene, F. von, and Mately C. A., 1933, "The Cretaceous Saurischia and Ornithischia of the central provinces of India", ''Palaeontologia Indica'', 21: 1-74〕 This last species is today commonly referred to the original ''Titanosaurus''. Huene based ''Laplatasaurus'' on fragmentary material found in three locations in Argentina, in strata of the Allen Formation, dating from the Campanian faunal stage. It consisted of limb elements, some dorsal vertebrae and a series of caudal vertebrae. Part of the finds had earlier been referred by Richard Lydekker to ''Titanosaurus australis''. Huene never assigned a holotype, but in 1979 José Fernando Bonaparte chose MLP 26-306 as the lectotype, a specimen consisting of a tibia and a fibula that perhaps originate from different individuals. Huene assigned those fossils to ''Laplatasaurus'' that seemed to indicate a rather large yet at the same time elegantly built sauropod. The about eighteen metres (60 ft) long ''Laplatasaurus'' was perhaps similar to ''Saltasaurus''. Osteoderms forming an armored plating on the back, have been referred to ''Laplatasaurus'' but the association is uncertain. These plates had much smaller ridges than those of ''Saltasaurus''. Huene placed ''Laplatasaurus'' in the Titanosauridae, which is still a common classification. In his 2003 review of South American titanosaurs, Jaime Eduardo Powell assigned ''Laplatasaurus'' to ''Titanosaurus'', creating the new combination ''Titanosaurus aurakanicus''.〔Powell, J. E., 2003, "Revision of South American titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects", ''Records of the Queen Victoria Museum'' 111: 1-173〕 Others however, continued to treat ''Laplatasaurus'' as valid genus separate from ''Titanosaurus''.〔Wilson, J. A. and Upchurch, P (2003) "A revision of ''Titanosaurus'' Lydekker (Dinosauria-Sauropoda), the first dinosaur genus with a "Gondwanan" distribution", ''Journal of Systematic Palaeontology'' 1(3): 125-160〕〔Upchurch, P., Barrett, P.M. and Dodson, P. 2004. Sauropoda. In The Dinosauria, 2nd edition. D. Weishampel, P. Dodson, and H. Osmólska (eds.). University of California Press, Berkeley. ISBN 0-520-24209-2, S. 259–322.〕〔Salgado, L. & Coria, R. A. 2005. Sauropods of Patagonia: Systematic update and notes on Global Sauropod evolution. In. Thunder-Lizards. The Sauropodomorph Dinosaurs. Ed. V. Tidwell & K. Carpenter. Indiana University Press. Bloomington and Indianopolis. Indiana University Press430-453.〕 A 2015 re-assessment of ''Laplatasaurus'' found it to be closely related to ''Bonitasaura'', ''Futalognkosaurus'', ''Mendozasaurus'', and ''Uberabatitan''. The genus was restricted to the lectotype, and the material from Rancho de Avila was assigned to cf. ''Bonitasaura'' sp.〔Pablo A. Gallina & Alejandro Otero (2015) Reassessment of Laplatasaurus araukanicus (SAUROPODA: TITANOSAURIA), from the Late Cretaceous of Patagonia, Argentina. ''Ameghiniana'' 52 (5):487–501. doi:10.5710/AMGH.08.06.2015.2911 http://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/1011〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Laplatasaurus」の詳細全文を読む スポンサード リンク
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