Banner & Desai (1988):
The test consists of about two whorls of chambers, 4 1/2 chambers in the first whorl and 4 in the final whorl. The spiral side is almost flat: the umbilical side is more convex and has a narrow, deep umbilicus which is in breadth equal to about 1/8 th of the test diameter. The chambers become reniform and depressed with growth, to become about half as high as long when seen on the spiral side. The aperture is a narrow slit, umbilical to extraumbilical, nearly but not quite reaching the periphery of the previous whorl, and is furnished with a porticus which is broadest at its umbilical end. The surface of the test is smooth and
nonmuricate: it is uniformly microperforate. the microperforations being about 0.6µm in diameter but often broadened at their outer ends (through test erosion) to about 1.5µm. |
Longoria,J.F. (1974): Stratigraphic, morphologic and taxonomic studies of Aptian planktonic Foraminifera . Revista Espanola de MicropaleontologíaNo extraord p. 1-107
Obata,I.; Maiya,S.; Inoue,Y. and Matsukawa,M. (1982): Integrate mega- and micro-fossil biostratigraphy of the Lower Cretaceous Choshi Group, Japan . Bull. Nation. Sci. Mus.C8(4) p. 145-179
Banner,F.T. and Desai,D. (1988): A review and revision of the Jurassic-Early Cretaceous Globigerinina, with special reference to the Aptian assemblages of Speeton (North Yorkshire, England) . J. micropalaeontol. Vol. 7(2) p. 143-185
Boudagher-Fadel,M.K.; Banner,F.T.; Whittaker,J.E. and Simmons,M.D. (1997): Early Evolutionary History of Planktonic Foraminifera. Vol. 1
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