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''Titanosaurus'' (meaning 'titanic lizard' - named after the mythological 'Titans', deities of Ancient Greece) is a dubious genus of sauropod dinosaurs, first described by Lydekker in 1877.〔Lydekker, R. (1877). "Notices of new and other Vertebrata from Indian Tertiary and Secondary rocks." ''Records of the Geological Survey of India'', 10(1): 30-43.〕 It is known from the Maastrichtian (Upper Cretaceous) Lameta Formation of India. ''Titanosaurus'' are estimated to have grown up to 9–12 metres (30–40 ft) long and about 13 tons in weight. ''Titanosaurus'' has traditionally been treated as a "wastebin taxon" for poorly preserved sauropod remains that demonstrate a distinctive vertebrae anatomy. The original ''Titanosaurus'' remains consist only of limb bones and a few vertebrae that have these characteristics. However, discoveries of more and better-preserved titanosaur species have shown that these once distinctive features are in fact widespread across many genera. Therefore, ''Titanosaurus'' itself is considered a ''nomen dubium'' ("dubious name") by most paleontologists, since the original ''Titanosaurus'' specimens cannot be distinguished from those of related animals.〔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.〕 ==Species== Numerous species have been historically assigned to ''Titanosaurus'', from southern Europe to South America. Only two among these, however, are currently considered species of ''Titanosaurus'': ''T. indicus'' and ''T. blandfordi'', both of which are considered nomina dubia. Other species formerly referred to this genus include: * ''"Titanosaurus" rahioliensis'' - Described based on teeth, this species is now considered an indeterminate neosauropod.〔 * ''"Titanosaurus" colberti'' - This species was the most well-known species of ''Titanosaurus'', but has been moved into its own genus, ''Isisaurus''.〔 * ''"Titanosaurus" australis'' - Known from relatively complete remains, but has been renamed ''Neuquensaurus''.〔 * ''"Titanosaurus" nanus'' - A small species found to be non diagnostic, and hence a nomen dubium.〔 * ''"Titanosaurus" robustus'' - Now referred to ''Neuquensaurus''.〔 * ''"Titanosaurus" madagascariensis'' - Considered a nomen dubium distinct from ''T. indicus'' or ''T. blandfordi''.〔 * ''"Titanosaurus" falloti'' - This large species, native to Laos, has disputed affinities. It has been considered synonymous with ''Tangvayosaurus'' and ''Huabeisaurus'', but the remains are too fragmentary to be sure.〔 * ''"Titanosaurus" valdensis'' - Referred to a new genus, ''Iuticosaurus'', but still considered a nomen dubium.〔 * ''"Titanosaurus" lydekkeri'' - Also referred to ''Iuticosaurus'', but its relation to ''I. valdensis'' is uncertain.〔 * ''"Titanosaurus" dacus'' - Now moved to the dwarf Titanosaur genus, ''Magyarosaurus''.〔 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「Titanosaurus」の詳細全文を読む スポンサード リンク
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