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''Scansoriopteryx'' ("climbing wing") is a genus of avialan dinosaur. Described from only a single juvenile fossil specimen found in Liaoning, China, ''Scansoriopteryx'' is a sparrow-sized animal that shows adaptations in the foot indicating an arboreal (tree-dwelling) lifestyle. It possessed an unusual, elongated third finger. The type specimen of ''Scansoriopteryx'' also contains the fossilized impression of feathers.〔Czerkas, S.A., and Yuan, C. (2002). "An arboreal maniraptoran from northeast China." Pp. 63-95 in Czerkas, S.J. (Ed.), ''Feathered Dinosaurs and the Origin of Flight.'' The Dinosaur Museum Journal 1. The Dinosaur Museum, Blanding, U.S.A. (PDF abridged version )〕 Most researchers regard this genus as a synonym of ''Epidendrosaurus'', with some preferring to treat ''Scansoriopteryx'' as the junior synonym,〔Padian, Kevin. (2001) "Basal Avialae" in "The Dinosauria" in "The Dinosauria: Second Edition" University of California Press. 2004.〕〔Feduccia, Alan, Lingham-Soliar, Theagarten, Hinchliffe, J. Richard. "Do feathered dinosaurs exist? Testing the hypothesis on neontological and paleontological evidence" "Journal of Morphology" 266:125-166〕 though it was the first name to be validly published.〔 ==Description== The type specimen of ''Scansoriopteryx heilmanni'' (specimen number CAGS02-IG-gausa-1/DM 607) represents the fossilized remains of a hatchling maniraptoran dinosaur, similar in some ways to ''Archaeopteryx''. A second specimen, the holotype of ''Epidendrosaurus ninchengensis'' (IVPP V12653), also shows features indicating it was a juvenile. The specimen is partially disarticulated, and most bones are preserved as impressions in the rock slab, rather than three-dimensional structures.〔Zhang, F., Zhou, Z., Xu, X. & Wang, X. (2002). "A juvenile coelurosaurian theropod from China indicates arboreal habits." ''Naturwissenschaften'', 89(9) 394-398. PMID 12435090.〕 Because the only known specimens are juvenile, the size of a full-grown ''Scansoriopteryx'' is unknown–the type specimen is a tiny, sparrow-sized creature.〔 ''Scansoriopteryx'' is also notable for its wide, rounded jaws. The lower jaw contained at least twelve teeth, larger in the front of the jaws than in the back. The lower jaw bones may have been fused together, a feature otherwise known only in the oviraptorosaurs. One distinctive feature of ''Scansoriopteryx'' is its elongated third finger, which is the longest on the hand, nearly twice as long as the second finger (in most theropod dinosaurs, the second finger is the longest). This is unlike the configuration seen in most other theropods, where the second finger is longest. The long wing feathers, or remiges, appear to attach to this long digit instead of the middle digit as in birds and other maniraptorans. Shorter feathers are preserved attached to the second finger.〔 ''Scansoriopteryx'' had a non-perforated hip socket, which is more open in most, but not all, other dinosaurs. It also had a pubis (hip bone) which pointed forward, a primitive trait among theropods, and unlike some maniraptorans more closely related to birds, where the pubis points downward or backward.〔 The legs were short, and preserve small pebbly scales along the upper foot (metatarsus), as well as possible impressions of long feathers in the same area, possibly similar to the "hind wings" of ''Microraptor'' and other basal paravians.〔 It also had an unusually large first toe, or hallux, which was low on the foot and may have been reversed, allowing some grasping ability.〔 The tail was long, six or seven times the length of the femur, and ended in a fan of feathers.〔 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「Scansoriopteryx」の詳細全文を読む スポンサード リンク
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