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
Hansenisca soldanii
(
d’Orbigny, 1826
)
Pl. 6, figs. 8a-b; pl. 7, figs. 1a–c
Gyroidina soldanii
d’Orbigny, 1826
, p. 278
;
d’Orbigny, 1846
, pl. 8, figs. 10–12;
Papp & Schmid, 1985
, p. 60
, pl. 50, figs. 4–9.
Gyroidinoides soldanii
Lowry, 1987
, p. 254
, pl. 15, figs. 9a–b;
Jones, 1994
, p. 106
, pl. 107, figs. 6–7;
Kender
et al.
, 2008
, p.
519, pl. 25, figs. 1–5;
Holbourn
et al
., 2013
, p. 278.
Description
: The test wall is calcareous and microperforate. The test is trochospiral and planoconvex to slightly unequally biconvex in side view. The spiral side is flat to slightly convex and the umbilical side highly convex. The approximately eight chambers in the final whorl gradually increase in size toward the apertural end and are separated by slightly depressed straight sutures. The sutures are radial on the spiral side and straight on the umbilical side. The umbilical sutures may be faint to slightly visible. The aperture is an interio-marginal slit, produced on a flap of the terminal chamber, extending onto the umbilical region.
Remarks:
This species occurs in minor to moderate abundances in the cores. The tests are moderately large, measuring up to
0.9 mm
in diameter.
Life strategy:
This species is epifaunal to shallow-infaunal (
Pérez-Asensio
et al.,
2012
), suboxic, unattached, preferring muddy substrates (
Murray, 1991
) on the slope (
Holbourn
et al
., 2013
).
Global stratigraphic range:
Hansenisca soldanii
occurs from the Oligocene to Recent (
Jones, 1994
).
Regional occurrence
:
Kender
et al.
(2008)
reported
H. soldanii
(=
Gyroidinoides soldanii
) from the Miocene in the
Congo
Basin. This study extends the spatial distribution of the species to the middle Miocene of the outer continental shelf of
Namibia
, south of the
Kunene
River mouth. This species also occurs in minor (<1%) to moderate (<50%) abundances along the slope of
Namibia
and southwestern
South Africa
from the
late Miocene
to Pleistocene. The highest abundances were recorded on the slope between
Walvis Bay
and Lüderitz,
Namibia
(
Wefer
et al
., 1998
).
Lowry (1987)
reported
H. soldanii
in surface sediments off the coast of northern
Namibia
to around the entire coastline of
South Africa
.