Bigenerina (Bigenerina) nodosaria d’Orbigny, 1826

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 7

Bigenerina (Bigenerina) nodosaria d’Orbigny, 1826

Pl. 1, fig. 4

Bigenerina nodoasaria d’Orbigny, 1826, p. 261 , pl. 11, figs. 9–12; Jones, 1994, p. 49, pl. 44, figs. 14–18.

Description: The test and chamber walls are agglutinated and well cemented. The test is elongate, with a slightly enlarged initial portion, which has a biserial arrangement, becoming uniserial in the later chamber arrangement. The initial portion is convex and slightly pointed. The sutures are depressed. The aperture is terminal and rounded in the centre of the final chamber. The aperture is rounded on a short neck above the terminal chamber.

Remarks: This species has a relatively large test size of up to 0.2x 1.5 mm. Few specimens have been found in cores 2670 and 2682, forming trace components (<1%) of the total benthic foraminifera assemblage.

Life strategy: The genus Bigenerina is infaunal ( Kender, 2007) under high eutrophic, high productivity marine conditions ( Fontanier et al., 2002).

Regional occurrence: Kender et al., (2008) reported Bigenerina sp. from the Congo Basin, but this species does not appear to be Bigenerina (Bigenerina) nodosaria . This study records the species in relatively low abundances (<5%) on the continental shelf of northern Namibia.