Spiroplectammina undetermined

Spiroplectammina sp. Pl. 1, figs. 1a–b Description: The chamber walls are agglutinated and well cemented. The test is flattened and broad, with the margins sub-rounded. In cross section, the test is trapezoid in shape. Chambers are initially planispiral, becoming biserial, with flush sutures. The ar...

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Bibliographic Details
Main Authors: Bergh, Eugene W., Compton, John S.
Format: Text
Language:unknown
Published: Zenodo 2022
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Online Access:https://dx.doi.org/10.5281/zenodo.5842146
https://zenodo.org/record/5842146
Description
Summary:Spiroplectammina sp. Pl. 1, figs. 1a–b Description: The chamber walls are agglutinated and well cemented. The test is flattened and broad, with the margins sub-rounded. In cross section, the test is trapezoid in shape. Chambers are initially planispiral, becoming biserial, with flush sutures. The arched aperture is situated along the margin of the terminal chamber. Remarks: Only a few tests were identified (not exceeding 5% in samples) in core 2670, measuring up to 0.4x 0.6 mm. The tests are commonly broken or have predatory holes. Life strategy: Species of the genus Spiroplectammina are infaunal in low oxygen environments (Hallam & Wignall, 1997) of increased food availability (Alegret & Thomas, 2007). Regional occurrence: This species is recorded to occur in the middle Miocene sediments of the Namibian outer continental shelf, south of the Kunene River mouth. : Published as part of Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, pp. 1-55 in Zootaxa 5091 (1) on page 6, DOI: 10.11646/zootaxa.5091.1.1, http://zenodo.org/record/5840434 : {"references": ["Hallam, A. & Wignall, P. B. (1997) Mass extinctions and their aftermath. Oxford University Press, Oxford, 328 pp.", "Alegret, L. & Thomas, E. (2007) Deep-Sea environments across the Cretaceous / Paleogene boundary in the eastern South Atlantic Ocean (ODP Leg 208, Walvis Ridge). Marine Micropalaeontology, 64, 1 - 17. https: // doi. org / 10.1016 / j. marmicro. 2006.12.003"]}