Marginal prolongation

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Fig. 1. Infundibulum and marginal prolongation. A: Neoeponides bradyi (Le Calvez), oblique-ventral view showing infundibulum. SEM graph; Gulf of Aqaba, Red Sea; Recent. B: Eponides repandus (Fichtel et Moll), ventral view showing marginal prolongation. SEM graph; Gulf of Aqaba, Red Sea; Recent. C: Schematic drawing showing position of marginal prolongations in respect to ventral and dorsal test morphology in the last whorl of Eponides repandus; gray: dorsal view with raised sutures; red: outline of chamber walls at level ventrally below periphery; green: ventral ouline of chambers below level of marginal prolongation; a: aperture; inf: infundibulum; mpr: marginal prolongation; per: (imperfotate) periphery; s(d): (oblique) septum (as seen in dorsal view); s(per): position of septum at level of periphery; ss(v): (radial) septal suture in ventral view; (Hottinger, 2006; fig. 61)[1] CC/BY-NC-SA)


  • according to Hottinger (2006):

MARGINAL PROLONGATION - (tectum); in a trochospiral test, a distally directed prolongation of the spiro-marginal portion of a chamber, leading the spiral sutures to be much more inclined on the spiral side than on the umbilical one.

Remarks: This feature has also been called tectum, a term preoccupied in fusulinids by the outermost layer of the chamber wall in the chamber roof. Therefore the term tectum is not acceptable as an alternative to "marginal prolongation".


Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744

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