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''Abydosaurus'' (meaning "Abydos lizard") is a genus of brachiosaurid sauropod dinosaur known from skull and postcranial material found in upper Lower Cretaceous rocks of northeastern Utah, United States. ==Discovery and description== ''Abydosaurus'' is one of the few sauropods known from skull material, with the first described complete skull for a Cretaceous sauropod from the Americas. It is also notable for its narrow teeth, as earlier brachiosaurids had broader teeth.〔 ''Abydosaurus'' is based on DINO 16488, a nearly complete skull and lower jaws with the first four neck vertebrae. Abundant skull and postcranial bones were found at the same site, including partial skulls from three additional individuals, a partial hip and associated tail vertebrae, a shoulder blade, an upper arm bone, and hand bones. These fossils were found in a sandstone bed at the base of the Mussentuchit Member of the Cedar Mountain Formation, near the old visitor center of Dinosaur National Monument. Zircons from mudstones beneath the bone-bearing sandstone indicate the age of the sandstone and the its contained bones is less than 104.46 ± 0.95 million years, in the Albian stage of the Early Cretaceous.〔 Although ''Abydosaurus'' lived some 45 million years after ''Giraffatitan'', the skulls of these two genera are similar except for the narrower, sharper teeth and smaller nose of ''Abydosaurus''. ''Abydosaurus'' can be differentiated from all other sauropods, including ''Giraffatitan'', by subtle features of the nasal and maxillary bones, its relatively small external nares (nostrils), and some features of the teeth.〔 ''Abydosaurus'' was named in 2010 by Daniel Chure and colleagues. The genus name is a reference to Egyptian mythology: Abydos is the Greek name for a city on the Nile where the head and neck of Osiris were buried, while the holotype of ''Abydosaurus'' consists of a head and neck found in rocks overlooking the Green River. The type species is ''A. mcintoshi'' in honor of John S. ("Jack") McIntosh,〔 Professor of Physics, Emeritus, Wesleyan University, and his contributions to Dinosaur National Monument and the study of sauropod dinosaurs.〔 While ''Abydosaurus'' is usually thought of as a small to midsize Brachiosaur, the referred adult material indicates a size up to 96 feet long and 55 tons in weight. 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「Abydosaurus」の詳細全文を読む スポンサード リンク
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