Amphicoryna sp.

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 19

Amphicoryna sp.

Pl. 3, figs. 6–7

Description: The test wall is calcareous and covered with ridges extending towards the base of each chamber. The test is elongate and uniserial, circular in cross-section, with several inflated globular chambers. Each chamber is not entirely rounded and has a flat base. Approximately twenty ridges run along the terminal chamber. The ridges increase in number towards the final chamber and terminate at the base of each chamber. The aperture is terminal at the end of a spiral neck.

Remarks: The larger terminal chamber is ~ 0.2 mm and the test is 0.6 mm in length. The relative abundance is generally low, forming minor components in some of the core samples.

This species differs from Amphicoryna scalaris in that the chambers are not entirely globular, but more rounded cone-shaped, where each chamber has a flatter base and where the ridges terminate.

Life strategy: The bathymetric range of Amphicoryna spp. is broad, extending from the shelf to abyssal depths. The preferred substrate is mud, under low oxygen (suboxic) ( Rögl & Spezzaferri, 2002; Kaminski, 2012) to high oxygen conditions ( Milker & Schmiedl, 2012).

Regional occurrence: This species occurs in middle Miocene sediments on the Namibian outer continental shelf, south of the Kunene River mouth (this study).