Laevidentalina inornata ( d’Orbigny, 1846 )

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 8-9

Laevidentalina inornata ( d’Orbigny, 1846)

Pl. 1, fig. 11

Dentalina inornata d’Orbigny, 1846, p. 44 , pl. 1, figs. 50–51; Papp & Schmid, 1985, p. 28, pl. 9, figs. 5–8.

Description: The test surface is smooth, calcareous, hyaline and circular in cross section. The test is elongate, arcuate and uniserial, with nine chambers gradually increasing in size towards the terminal end. The proloculus is rounded. The sutures are depressed and horisontal. The aperture is terminal, with slits radiating towards the end.

Remarks: Few tests of this species were recorded, comprising <1% of the total foraminiferal assemblage in core 2670. The tests are up to 1 mm long and thin, measuring 0.1 mm in cross-section.

The classification was made as Laevidentalina , based on the description in Loeblich & Tappan (1988). It is distinguished from Dentalina in having a smooth surface, rather than having longitudinal costae.

Life strategy: The genus Laevidentalina is infaunal ( Alegret et al., 2003) and occurs under a variety of oxic conditions, e.g., under high oxygen conditions in the Mediterranean Sea ( Cimerman & Langer, 1991; Sgarrella & Moncharmont Zei, 1993; Milker & Schmiedl, 2012) and under suboxic to dysoxic conditions ( Rögl & Spezzaferri, 2002).

Global stratigraphic range: The stratigraphic range for the genus Laevidentalina is Cretaceous to Recent ( Loeblich & Tappan, 1988).

Regional occurrence: This study records L. inornata to occur in middle Miocene sediments on the Namibian outer continental shelf, south of the Kunene River mouth.