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The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, at 358.9 ± 0.4 million years ago, to the beginning of the Permian Period, at 298.9 ± 0.15 Ma. The name ''Carboniferous'' means "coal-bearing" and derives from the Latin words ''carbō'' (“coal”) and ''ferō'' (“I bear, I carry”), and was coined by geologists William Conybeare and William Phillips in 1822.〔Rev. W. D. Conybeare and William Phillips, ''Outlines of the Geology of England and Wales'' …, Part I, (London, England: William Phillips, 1822). On page 323, Conybeare titles the chapter ("Book III. Medial or Carboniferous Order." )〕 Based on a study of the British rock succession, it was the first of the modern 'system' names to be employed, and reflects the fact that many coal beds were formed globally during this time.〔Cossey, P.J. et al. (2004) ''British Lower Carboniferous Stratigraphy'', Geological Conservation Review Series, no 29, JNCC, Peterborough (p3)〕 The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial life was well established by the Carboniferous period. Amphibians were the dominant land vertebrates, of which one branch would eventually evolve into reptiles, the first fully terrestrial vertebrates. Arthropods were also very common, and many (such as ''Meganeura''), were much larger than those of today. Vast swaths of forest covered the land, which would eventually be laid down and become the coal beds characteristic of the Carboniferous system. The atmospheric content of oxygen also reached their highest levels in history during the period, 35% compared with 21% today. This increased the atmospheric density by a third over today’s value.〔 A minor marine and terrestrial extinction event occurred in the middle of the period, caused by a change in climate. The later half of the period experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. ==Subdivisions== In the United States the Carboniferous is usually broken into Mississippian (earlier) and Pennsylvanian (later) subperiods. The Mississippian is about twice as long as the Pennsylvanian, but due to the large thickness of coal bearing deposits with Pennsylvanian ages in Europe and North America, the two subperiods were long thought to have been more or less equal in duration.〔Menning ''et al.'' (2006)〕 In Europe the Lower Carboniferous sub-system is known as the Dinantian, comprising the Tournaisian and Visean Series, dated at 362.5-332.9 Ma, and the Upper Carboniferous sub-system is known as the Silesian, comprising the Namurian, Westphalian, and Stephanian Series, dated at 332.9-290 Ma. The Silesian is roughly contemporaneous with the late Mississippian Serpukhovian plus the Pennsylvanian. In Britain the Dinantian is traditionally known as the Carboniferous Limestone, the Namurian as the Millstone Grit, and the Westphalian as the Coal Measures and Pennant Sandstone. The faunal stages from youngest to oldest, together with some of their subdivisions, are: Late Pennsylvanian: Gzhelian (most recent) * Noginskian / Virgilian ''(part)'' Late Pennsylvanian: Kasimovian * Klazminskian * Dorogomilovksian / Virgilian ''(part)'' * Chamovnicheskian / Cantabrian / Missourian * Krevyakinskian / Cantabrian / Missourian Middle Pennsylvanian: Moscovian * Myachkovskian / Bolsovian / Desmoinesian * Podolskian / Desmoinesian * Kashirskian / Atokan * Vereiskian / Bolsovian / Atokan Early Pennsylvanian: Bashkirian / Morrowan * Melekesskian / Duckmantian * Cheremshanskian / Langsettian * Yeadonian * Marsdenian * Kinderscoutian Late Mississippian: Serpukhovian * Alportian * Chokierian / Chesterian / Elvirian * Arnsbergian / Elvirian * Pendleian Middle Mississippian: Visean * Brigantian / St Genevieve / Gasperian / Chesterian * Asbian / Meramecian * Holkerian / Salem * Arundian / Warsaw / Meramecian * Chadian / Keokuk / Osagean ''(part)'' / Osage ''(part)'' Early Mississippian: Tournaisian (oldest) * Ivorian / ''(part)'' / Osage ''(part)'' * Hastarian / Kinderhookian / Chouteau 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「Carboniferous」の詳細全文を読む スポンサード リンク
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