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''Schwagerina'' is an extinct fusulinacean genus of (Foraminifera that is used as an Early Permian index fossil. The overall shape of the shell or test is fusiform to subcylindrical, the spirotheca, or outer test wall, is thick, and composed of tectum and alveolar keriotheca; the septa are fluted throughout the length of the shell, intense to top of chambers in some, only in lower parts in others; axial fillings highly variarble, chomata distinct or thin and discontinuous. Tectum is the thin, dark, dense outer layer of the spirotheca, Keriotheca is the thicker, honeycomb-like alveolar, inner layer. Chomata are mounds secreted on the floor of the chamber that connect either side of the tunnel, which interconnects the chambers. ''Daixina'' Ryzovskaya, 1949, is given (Loeblich and Tappan 1964)〔Alfred R. Loeblich Jr and Helen Tappan, 1964. Sarcodina Chiefly "Thecamoebians" and Foraminiferida; Treatise on Invertebrate Paleontology, Part C Protista 2. Geological Society of America and University of Kansas Press.〕 as a synonym of ''Schwagerina''. Three genera are similar to ''Schwagerina'', but differ in their internal details. They are: ''Paraschagerina'', Dunbar and Skinner 1939, from the Lower Permian. The spirotheca is structured as in ''schwagerina''; the first two or three volutions tightly coiled and elongate-fusiform, the outer volutions distinctly inflated-fusiform; septa highly fluted throughout. ''Pseudoschwagerina'' Dunbar and skinner, 1936, Lower Permia. Shell inflated-fusimform; first two or three volutions tightly coiled, outer ones inflacted; spirotheca as in Schwaterina. Septa are fluted at the base, close speced at first, wide spaced later. ''Occidentoschagerina'' is given as a junior synonym. ''Rugososchwagerina'' Milukho-Maklay, 1959, Upper Permian. Shell inflated-fusiform. First three or four volutions tightly coiled, elongate-fusiform, outer volutions greatly inflated. Spirotheca as with Schwagerina, moderately thin in the tightly coiled portion and next one or two volutions, becoming thick and more coarsely alveolar in the outer two or three. Septa are close spaced in the first three or four volutions, wide spaced in the next two or three, and again close spaced in the outermost. ==References== 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「Schwagerina」の詳細全文を読む スポンサード リンク
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