Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf
Author
Bergh, Eugene W.
0000-0002-0765-4141
Marine Research Institute and Department of Geological Sciences, University of Cape Town, Private Bag X 3, Rondebosch, 7701, South Africa. & Department of Environmental and Geographical Sciences, University of Cape Town, Private Bag X 3, Rondebosch, 7701, South Africa; & Invertebrate palaeontology and Geology, Iziko South African Museum, P. O. Box 61, Cape Town 8000, South Africa. john. compton @ uct. ac. za; https: // orcid. org / 0000 - 0002 - 0765 - 4141
john.compton@uct.ac.za
Author
Compton, John S.
Marine Research Institute and Department of Geological Sciences, University of Cape Town, Private Bag X 3, Rondebosch, 7701, South Africa.
text
Zootaxa
2022
2022-01-12
5091
1
1
55
journal article
2636
10.11646/zootaxa.5091.1.1
51b42715-ddb1-4b4a-aad4-8be0f600a287
1175-5326
5840434
ABC8AF70-F691-4D07-8F20-70934642C8BC
Grigelis semirugosus
(
d’Orbigny, 1846
)
Pl. 1, fig. 15
Nodosaria pyrula
d’Orbigny, 1826
, p. 253
, fig. 13.
Nodosaria semirugosa
d’Orbigny, 1846
, p. 34
, pl. 1, fig. 20–23;
Papp & Schmid, 1985
, p. 24
, pl. 4, figs. 6–8.
Grigelis semirugosa
Jones, 1994
, p. 75
, pl. 63, figs. 23–27.
Description:
The wall is calcareous, hyaline. The test is elongate, uniserial and semi-circular in cross section. The chambers are rounded and oval in shape.A tubular neck separates each chamber from the next. Ridges are prominent on the base of each chamber. The rounded aperture is terminal at the end of a long thin neck.
Remarks:
Few specimens of this species were recorded, comprising <1% of the total foraminiferal assemblage in core 2670. Tests are long, measuring
0.25 mm
in cross-section and up to
3 mm
in length.
Life strategy:
Species of the genus
Grigelis
are infaunal, under suboxic conditions (
Pezelj
et al
., 2013
).
Global stratigraphic range:
This species is recorded to occur from the Miocene to Recent (
Jones, 1994
).
Regional occurrence:
Grigelis semirugosus
occurs in middle Miocene sediments on the Namibian outer continental shelf, south of the
Kunene
River
mouth (this study).