|
''Rosalina'' is a foraminiferal genus included in the rotaliid family Rosalinidae. ''Rosalina'' has a smooth plano-convex to concavo-convex trochospiral test in which the chambers are rapidly enlarging and all visible on the convex spiral side and subtriangular and strongly overlapping on the umbilical side, the final chamber taking up about one-third of the circumference. Sutures on the spiral side are depressed and oblique, curving back at the periphery. The umbilicus is open, partly covered by triangular umbilical flaps extending from each chamber of the final whorl. Chamber interiors are simple and undivided with subacute peripheries. Walls are calcareous, with an organic inner lining, and are distinctly perforate. The aperture is a low interiomarginal arch near the periphery on the umbilical side, with narrow bordering lip. ''Rosalina'' has a stratigraphic range from the Eocene to recent and a cosmopolitan distribution. Related genera include ''Neoconorbina'', ''Rotorboides'', and ''Semirosalina''. ==References== *Joseph A. Cushman, 1950. Foraminifera, their classification and economic use. Harvard University Press, Cambridge, Massachusetts. 4th edition, 1950 *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, 1964. *Alfred R. Loeblich,jr. and Helen Tappan, 1988. Forminiferal Genera and their classification. Geological Survey of Iran, (e-book) 2005. () 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「Rosalina (genus)」の詳細全文を読む スポンサード リンク
|