Anomalinoides helicinus ( Costa, 1855 )

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 29

Anomalinoides helicinus ( Costa, 1855)

Pl. 6, figs. 6–7

Nonionina helicina Costa, 1855 , p. 123, pl. 1, figs. 18a–c.

Anomalina helicina Christodolou, 1960, p. 89 , pl. 8, figs. 5a–c.

Description: The test wall is calcareous with coarsely perforate chambers and smooth sutures separating the chambers. The test is rounded and trochospiral, with a small central boss. The approximately twelve chambers in the final whorl gradually increase in size and become inflated toward the apertural end. The curved radial sutures appear slightly raised between the coarsely perforate chambers on the umbilical side. The sutures are curved away from the apertural end. A flap extends from each suture between chambers, slightly extending over the umbilicus. The aperture is an arched interio-marginal slit against the margin of the previous whorl with an upper lip.

Remarks: The relative abundances of A. helicinus are minor (<5%) in all three cores. The tests are moderate in size, measuring 0.6 mm in diameter.

Life strategy: This species is epifaunal-shallow infaunal ( Pérez-Asensio et al., 2012).

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