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rhamphorhynchoidea
The Rhamphorhynchoidea forms one of the two suborders of pterosaurs and represent an evolutionary grade of primitive members of this group of flying reptiles. This suborder is paraphyletic in relation to the Pterodactyloidea, which arose from within the Rhamphorhynchoidea, not from a more distant common ancestor. Because it is not a completely natural grouping, Rhamphorhynchoidea is not used as a formal group in most scientific literature, though some pterosaur scientists continue to use it as an informal grouping in popular works, such as ''The Pterosaurs: From Deep Time'' by David Unwin, and in some formal studies. Rhamphorhynchoids were the first pterosaurs to have appeared, in the late Triassic Period (Norian age, about 210 million years ago〔Butler, R.J., Barrett, P.M., and gower, D.J. (2009). "Postcranial skeletal pneumaticity and air-sacs in the earliest pterosaurs." ''Biology Letters'', 5(4): 557-560. 〕). Unlike their descendants the pterodactyloids, most rhamphorhynchoids had teeth and long tails, and most species lacked a bony crest, though several are known to have crests formed from soft tissue like keratin. They were generally small. Nearly all had become extinct by the end of the Jurassic Period, though least one anurognathid genus, Dendrorhynchoides, persisted to the early Cretaceous. The family Wukongopteridae, which shows a mix of rhamphorynchoid and pterodactyloid features, is known from the Daohugou Beds which are most commonly dated to the Jurassic, but a few studies give a Cretaceous date.〔Yuan, Wang and Evans, Susan, ("A new short-bodied salamander from the Upper Jurassic/Lower Cretaceous of China" ), ''Acta Palaeontological Polonica'' 51 (1): 127-130, 2006〕〔Fucheng Zhang, Zhonghe Zhou, Xing Xu, Xiaolin Wang & Corwin Sullivan, ("A bizarre Jurassic maniraptoran from China with elongate ribbon-like feathers" ), ''Nature'' 455, 1105-1108 (23 October 2008). The authors note that "The age of the Daohugou sediments is contentious, with possible dates ranging from Middle Jurassic to Early Cretaceous. However, published radioisotopic dating results span a narrower range from 152 to 168 Myr (Middle to Late Jurassic)"〕 Further more, remains of a non-pterodactyloid from the Candeleros Formation extend the presence of basal pterosaurs into the at least early Late Cretaceous.〔Haluza, A. Y Apesteguía, S, Pterosaur remains (Archosauria, Ornithodira) from the early Late Cretaceous of “La Buitrera”, Río Negro, Argentina, Jornada; XXIII Jornadas Argentinas de Paleontología de Vertebrados; 2007〕
==Classification==
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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