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
Lenticulina cultrata
(
Montfort, 1808
)
Pl. 2, figs. 6a–b
Robulus cultrata
de Montfort, 1808
, p. 214
, fig. 54e.
Lenticulina cultrata
Kohl, 1985
, p. 47
, pl. 10, fig. 6–7;
Weidich, 1990
, p. 123
.
Description:
The wall is calcareous, smooth and finely perforate. The test is planispiral, involute and biconvex, with a peripheral keel. The chambers gradually increase in size toward the terminal aperture. The sutures are flush and slightly curved. The aperture is radiate and terminal.
Remarks:
Specimens are relatively large, with a diameter of up to
1 mm
. The relative abundance is generally low, forming minor components (<5%) in some of the core samples.
Lenticulina cultrata
is similar to other species in this genus, but can be distinguished by its rounded shape and concave profile, that is supported by its central pillar. The terminal apertural face is also straight, extending from the aperture to the central boss.
Life strategy:
Species of the genus
Lenticulina
are generally epifaunal (
Corliss and Chen, 1988
) under oxic (
Pezelj
et al.,
2013
and references therein) to suboxic conditions (
Kaiho, 1994
).
Global stratigraphic range:
McMillan (2003)
identified
L. cultrata
in Cretaceous deposits, extending the stratigraphic range for this species to that period.
Regional occurrence:
This species has been reported in early Cretaceous-aged deposits of the
Eastern Cape
,
South Africa
(
McMillan, 2003
). This study documents the species in middle Miocene sediments on the Namibian outer continental shelf, south of the Kunene River mouth (this study).