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
Amphicoryna scalaris
(
Batsch, 1791
)
Pl. 3, figs. 5a–b
Nautilus (Ortoceras) scalaris
Batsch, 1791
, p. 2
, pl. 2, figs. 4a–b.
Nodosaria scalaris
Brady, 1884
, p. 510
, pl. 63, figs. 28–31.
Amphycorine falx
Brady, 1884
, p. 556
, pl. 65, figs. 7–9.
Amphicoryna scalaris
Loeblich and Tappan, 1988
, p. 410
, pl. 450, figs. 11–15;
Jones, 1994
, p. 77
, pl. 65, figs. 7–9;
Yassini & Jones, 1995
, p. 136
, fig. 724;
Murray, 2003
, p. 17
, fig. 5.1;
Milker and Schmiedl, 2012
, p. 73
, fig. 18.22–25.
Description
: The test wall is calcareous and the surface covered with ridges running along most of the length of the chambers. The test is elongate and uniserial, circular in cross-section, with several inflated globular chambers, separated by deeply incised sutures. A maximum of approximately twenty ridges run along the terminal chamber. The ridges increase in number towards the terminal chamber and do not extend the full length of the chambers. The aperture is terminal at the end of a neck.
Remarks:
Specimens are small to moderate in size, with the larger terminal chamber reaching ~
0.15 mm
and the test
0.6 mm
in length. The relative abundance is generally low, forming minor components in some of the core samples.
Life strategy:
The bathymetric range of
Amphicoryna
spp.
is broad, from the shelf to abyssal depths. The preferred substrate is mud, under low oxygen (suboxic) (
Rögl & Spezzaferri, 2002
;
Kaminski, 2012
) to high oxygen conditions (
Milker & Schmiedl, 2012
).
Regional occurrence
:
Amphicoryna scalaris
occurs in middle Miocene sediments on the Namibian outer continental shelf, south of the
Kunene
River
mouth (this study).