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''Saichania'' (Mongolian meaning "beautiful one") is a genus of herbivorous ankylosaurid dinosaur from the Late Cretaceous period of Mongolia and China. The first fossils of ''Saichania'' were found in the early 1970s in Mongolia. In 1977 the type species ''Saichania chulsanensis'' was named. The description of this species has been based on limited fossil material; especially the rear of the animal is not well known. ''Saichania'' was over five metres long and weighed over two tonnes. It was more robustly built than other members of the Ankylosauridae. Neck vertebrae, shoulder girdle, ribs and breast bones were fused or firmly connected. Its body was flat and low-slung, standing on four short legs. The forelimbs were very powerful. The head was protected by bulbous armour tiles. It could defend itself against predators like ''Tarbosaurus'' with a tail-club. On the torso keeled osteoderms were present. ''Saichania'' bit off plants in its desert habitat with a horny beak and processed them in its wide hindgut. ==History of discovery== In 1970 and 1971 a Polish-Mongolian expedition found ankylosaurian fossils in the Gobi Desert near Chulsan, or Khulsan. The type species ''Saichania chulsanensis'' was named and described by the Polish palaeontologist Teresa Maryańska in 1977, along with the related species ''Tarchia kielanae''. The generic name means "the beautiful one" in Mongolian, referring to the pristine state of preservation of the type specimen. The specific name refers to the provenance near Chulsa. The holotype of ''Saichania chulsanensis'', specimen GI SPS 100/151, was found in a layer of the Barun Goyot Formation, dating from the late Campanian, about seventy-three million years old. It consists of a skull and the anterior part of the postcranial skeleton: seven neck vertebrae, ten back vertebrae, the left shoulder girdle, the left forelimb, the two cervical halfrings and extensive armour in life position. The holotype is largely articulated. Referred specimens include ZPAL MgD-I/114 consisting of an undescribed fragmentary skull roof and associated armour, and an undescribed, almost complete skeleton with skull, specimen PIN 3142/251. Later, also the juvenile specimen MPC 100/1305 was referred and extensively described in 2011, seeming for the first time to provide complete information on the postcranial skeleton.〔Carpenter, K., Hayashi, S., Kobayashi, Y., Maryańska, T., Barsbold, R., Sato, K., and Obata, I., 2011, "''Saichania chulsanensis'' (Ornithischia, Ankylosauridae) from the Upper Cretaceous of Mongolia", ''Palaeontographica, Abteilung A'', 294(1-3): 1-61〕 However, in 2014 Victoria Megan Arbour concluded that the describers had been misled by the skeleton having been completed with a skull cast of GI SPS 100/151, and that the remainder of the fossil belonged to some other ankylosaur, possibly ''Pinacosaurus''. On the other hand, Arbour added to the number of possible ''Saichania'' specimens by referring PIN 3142/250, a skull previously seen as a ''Tarchia'' exemplar. This would imply that ''Saichania'', formerly thought to occur solely in the Barun Goyot Formation at Khulsan, is also known from the Nemegt Formation at Khermeen Tsav. ''Saichania'' would then be the only ankylosaur definitely known from the Nemegt, its occurrence thus spanning the time of the Campanian–Maastrichtian transition, and early Maastrichtian (Nemegtian) period. Arbour also considered the Chinese taxa ''Tianzhenosaurus youngi'' Pang & Cheng 1998 and ''Shanxia tianzhenensis'' Barrett, You, Upchurch & Burton 1998 to be junior synonyms of ''Saichania''.〔Arbour, Victoria Megan, 2014. ''Systematics, evolution, and biogeography of the ankylosaurid dinosaurs''. Ph.D thesis, University of Alberta〕 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「Saichania」の詳細全文を読む スポンサード リンク
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