Orthomorphina jedlitschkai ( Thalmann, 1937 )

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 24

Orthomorphina jedlitschkai ( Thalmann, 1937)

Pl. 5, fig. 2

Nodogenerina jedlitschkai Thalmann, 1937, p. 341 .

Orthomorphina jedlitschkai Barker, 1960 , pl. 62, fig. 1–2; Jones, 1994, pl. 62, fig. 1–2, suppl. pl. 1, fig. 16, suppl. pl. 2, fig. 6–7; Hayward et al., 2012, p. 136, pl. 8, fig. 24–27.

Description: The test wall is calcareous and generally smooth. The test is elongate, uniserial, with globular chambers and circular in cross-section. The chambers are of different diameters and separated from each other by deep incised sutures. The penultimate chamber is larger than the terminal chamber. The aperture is surrounded by a round thick rim.

Remarks: Few tests of this species were recorded in this study, forming a trace component (<1%) in core 2670. The tests are moderate in size. The broadest chamber measures 0.3 mm in cross section and the test measures up to 0.8 mm in length.

Jones (1994) illustrated the similarity in test morphology between O. jedlitschkai and Glandulonodosaria spp. Based on the shape of the aperture (slightly protruding and rounded) and resemblance to the test morphology displayed in Jones (1994), this specimen has been assigned to Orthomorphina jedlitschkai .

Life strategy: Species of the genus Orthomorphina are recorded to be infaunal under suboxic conditions ( Pezelj et al., 2013 and references therein).

Global stratigraphic range: Orthomorphina jedlitschkai is an extinct species, occurring from the Cretaceous to Pleistocene ( Hayward et al., 2012).

Regional occurrence: This is the first documentation of this species to occur in the region and in middle Miocene sediments on the Namibian outer continental shelf, south of the Kunene River mouth (this study).