Lenticulina iota Barker 1960
Creators
- 1. 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
- 2. Marine Research Institute and Department of Geological Sciences, University of Cape Town, Private Bag X 3, Rondebosch, 7701, South Africa.
Description
Lenticulina iota (Cushman, 1923a) Pl. 2, figs. 9a–b
Cristellaria cultrata Brady, 1884, p. 550, pl. 70, fig. 4–6.
Cristellaria iota Cushman, 1923a, p. 111, pl. 29, fig. 2; pl. 30, fig. 1.
Lenticulina iota Barker, 1960, pl. 70, fig. 4–6; Thomas, 1988, p. 74, pl. 1, fig. 10; Jones, 1994, p. 81, pl. 70, fig. 4–6; Holbourn et al., 2013, p. 336.
Description: The test wall is calcareous, smooth and finely perforate. The test is planispiral, involute and biconvex in side view. A keel surrounds the test margin. The keel is initially broad, narrowing towards the terminal end. The chambers gradually increase in size. The sutures are flush and curved. The aperture is radiate and terminal.
Remarks: Specimens are relatively large, measuring up to 1 mm in diameter.The relative abundance is generally low, forming minor components (<1%) in some of the core samples.
Similar to most other species in this genus, L. iota is rounded, but is distinguished from the other Lenticulina spp. by its broad and thin, near transparent or translucent keel around the margin of the test. The umbilical pillar is also thicker and more pronounced, compared to other species, e.g., L. cultrata.
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). The bathymetric range of Lenticulina iota is given as shelf to upper slope (Holbourn et al., 2013).
Global stratigraphic range: This species is extant and occurs from the Miocene to Recent (Thomas, 1988).
Regional occurrence: This study documents L. iota to occur in middle Miocene sediments on the outer Namibian continental shelf, south of the Kunene River mouth (this study). Lowry (1987) recorded this species from the continental shelf in surface sediments off Cape Agulhas, South Africa.
Notes
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Linked records
Additional details
Identifiers
Biodiversity
- Family
- Vaginulinidae
- Genus
- Lenticulina
- Kingdom
- Chromista
- Order
- Vaginulinida
- Phylum
- Foraminifera
- Scientific name authorship
- Barker
- Species
- iota
- Taxon rank
- species
- Taxonomic concept label
- Lenticulina iota Barker, 1960 sec. Bergh & Compton, 2022
References
- Cushman, J. A. (1923 a) The foraminifera of the Atlantic Ocean: part 4 - Lagenidae. Bulletin of the United States National Museum, 104 (4), 1 - 228. https: // doi. org / 10.5479 / si. 03629236.104.3
- Brady, H. B. (1884) Report of the foraminifera dredged by H. M. S. Challenger during the years 1873 - 1876. Zoology, 9, 1 - 814.
- Barker, R. W. (1960) Taxonomic notes on the species figured by H. B. Brady in his report on the Foraminifera dredged by H. M. S. Challenger during the years 1873 - 1876. Society of Economic Palaeontologists and Mineralogists, Special Publication, 9, 1 - 238.
- Thomas, F. C. (1988) Taxonomy and stratigraphy of selected Cenozoic benthic foraminifera, Canadian Atlantic margin. Micropaleontology, 34 (1), 67 - 82. https: // doi. org / 10.2307 / 1485612
- Jones, R. W. (1994) The Challenger Foraminifera. Oxford University Press, Oxford, 149 pp.
- Holbourn, A., Henderson, A. S. & MacLeod, N. (2013) Atlas of Benthic Foraminifera. Wiley-Blackwell, Oxford, 654 pp. https: // doi. org / 10.1002 / 9781118452493
- Corliss, B. H. & Chen, C. (1988) Morphotype patterns of Norwegian Sea deep-sea benthic foraminifera and ecological implications. Geology, 16 (8), 716 - 719. https: // doi. org / 10.1130 / 0091 - 7613 (1988) 016 <0716: MPONSD> 2.3. CO; 2
- Pezelj, D, Mandic, O. & Coric, S. (2013) Paleoenvironmental dynamics in the southern Pannonian Basin during initial Middle Miocene marine flooding. Geologica Carpathica, 64, 81 - 100.
- Kaiho, K. (1994) Benthic foraminiferal dissolved-oxygen index and dissolved-oxygen levels in the modern ocean. Geology, 22 (8), 719 - 722. https: // doi. org / 10.1130 / 0091 - 7613 (1994) 022 <0719: BFDOIA> 2.3. CO; 2
- Lowry, F. M. D. (1987) Foraminiferal thanatocoenoses from the continental shelf of southern Africa. Unpublished Ph. D. thesis, University College, London, 443 pp.