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''Largocephalosaurus'' is an extinct genus of basal saurosphargid, a marine reptile known from the Middle Triassic (Anisian age) Guanling Formation of Yunnan and Guizhou Provinces, southwestern China. It contains a type species, ''Largocephalosaurus polycarpon'', and a second species ''L. qianensis''. ''L. polycarpon'' was initially interpreted as an eosauropterygian sauropterygian closely related to European pachypleurosaurs and nothosaurids.〔 However following additional preparation of the postcranial skeleton and the discovery of a second better known species ''L. qianensis'', Li ''et al.'' (2014) reinterpreted ''Largocephalosaurus'' as a basal member of the family Saurosphargidae and a close relative of ''Saurosphargis'' and ''Sinosaurosphargis''. According to Li ''et al.'' (2014), saurosphargids did not belong to Sauropterygia, although they were closely related to it, forming its sister taxon.〔 ==Discovery== The type species of ''Largocephalosaurus'', ''L. polycarpon'' is known only from the holotype WIGM SPC V 1009 a nearly complete and articulated skull and skeleton missing most of its tail and measuring more than 113 cm in length, housed at the Wuhan Institute of Geology and Mineral Recourses. SPC V 1009 was collected from Member II of the Guanling Formation, dating to the Pelsonian substage of the mid-late Anisian stage of the early Middle Triassic, about 243 million years ago, at Luoping County of Yunnan Province.〔 While ''L. polycarpon'' was being studied at the WIGM, three specimens of what was later named ''L. qianensis'', where prepared at the Geological Museum of Peking University and the Institute of Vertebrate Paleontology and Paleoanthropology. These three specimens were collected in 2008 about 100 km northeast of the type locality of ''L. polycarpon'' at Xinmin District of Panxian County, southwestern Guizhou Province. They, like SPC V 1009, came from Member II of the Guanling Formation, dating to the late Anisian. Out of these specimens, IVPP V 15638, a nearly complete skeleton exposed in view from below with only the back of the tail missing, was chosen to represent the holotype of ''L. qianensis''. The other two specimen are referable to ''L. qianensis'' and include GMPKU-P-1532-A, a skull with a neck vertebra in view from above, and GMPKU-P-1532-B, an incomplete postcranial skeleton in view from above, with the back portion of the mandible preserved, but missing most of the tail.〔 All specimens of ''Largocephalosaurus'' came from the Lagerstätte discovered during a 2007 geological mapping project with a diverse record of marine life called Luoping Biota, that yielded, apart from ''Largocephalosaurus'', various invertebrates, fish, basal ichthyosaurs, ''Atopodentatus'', the advanced saurosphargid ''Sinosaurosphargis'', and several species of eosauropterygian, including both pachypleurosaurs and nothosaurids.〔 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「Largocephalosaurus」の詳細全文を読む スポンサード リンク
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