Lenticulina gibba

Lenticulina gibba (d’Orbigny, 1839) Pl. 2, figs. 7–8 Cristellaria gibba d’Orbigny, 1839, p. 40, pl. 7, figs. 20–21; Brady, 1884, p. 546, pl. 69, figs. 8–9. Robulus oblongus Coryell & Rivero, 1940, p. 332, pl. 43, fig. 12. Robulus gibbus Bermúdez, 1949, p. 126, pl. 7, figs. 53–54. Lenticulina gib...

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Bibliographic Details
Main Authors: Bergh, Eugene W., Compton, John S.
Format: Text
Language:unknown
Published: Zenodo 2022
Subjects:
Online Access:https://dx.doi.org/10.5281/zenodo.5840488
https://zenodo.org/record/5840488
Description
Summary:Lenticulina gibba (d’Orbigny, 1839) Pl. 2, figs. 7–8 Cristellaria gibba d’Orbigny, 1839, p. 40, pl. 7, figs. 20–21; Brady, 1884, p. 546, pl. 69, figs. 8–9. Robulus oblongus Coryell & Rivero, 1940, p. 332, pl. 43, fig. 12. Robulus gibbus Bermúdez, 1949, p. 126, pl. 7, figs. 53–54. Lenticulina gibba Barker, 1960, pl. 69, figs. 8–9; Lowry, 1987, p. 168, pl. 9, fig.2; Jones, 1994, p. 81, pl. 69, figs. 8–9; Robertson, 1998, p. 66, pl. 22, fig. 4. Description: The test wall is calcareous, smooth and finely perforate. The test is planispiral involute and longer than wide; biconvex in side view. A narrow keel surrounds the periphery of the test, becoming narrower along later chambers. There are six to nine chambers in the final whorl. The chambers gradually increase in size toward the terminal chamber. The sutures are flush and slightly curved. The aperture is radiate and terminal. Remarks: Specimens are moderately sized, measuring 0.5 mm in diameter and 0.75 mm in length. The relative abundance is generally low, forming minor components (<5%) in some of the core samples. This species appears more elongated and oblong compared to other Lenticulina species in the assemblage. The central boss, from where the test’s curved radial sutures extend, is not as largely developed as many other species. There is a variation in the width of the keel between specimens of this species. 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 gibba is reported as shelf to upper slope (Holbourn et al ., 2013). Global stratigraphic range: This species is documented to be extant and occurs in early Miocene to Recent strata (Holbourn et al ., 2013). Regional occurrence: This study records L. gibba to occur in middle Miocene sediments on the Namibian outer continental shelf, south of the Kunene River mouth (this study). Lowry (1987) recorded this species in surface sediments on the continental shelf off Cape St. Blaize, Mossel Bay, on the southern margin of South Africa. : 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 15, DOI: 10.11646/zootaxa.5091.1.1, http://zenodo.org/record/5840434 : {"references": ["d'Orbigny, A. D. (1839) Foraminiferes. In: de la Sagra, R. (Ed.), Histoire physique, politique et naturelle de I'ile de Cuba. A. Bertrand, Paris, pp. 1 - 224.", "Brady, H. B. (1884) Report of the foraminifera dredged by H. M. S. Challenger during the years 1873 - 1876. Zoology, 9, 1 - 814.", "Coryell, H. N. & Rivero, F. C. (1940) A Miocene microfauna of Haiti. Journal of Palaeontology, 14, 324 - 344.", "Bermudez, P. J. (1949) Tertiary smaller foraminifera of the Dominican Republic. Cushman Laboratory for Foraminiferal Research Special Publication, 25, 1 - 322.", "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.", "Lowry, F. M. D. (1987) Foraminiferal thanatocoenoses from the continental shelf of southern Africa. Unpublished Ph. D. thesis, University College, London, 443 pp.", "Jones, R. W. (1994) The Challenger Foraminifera. Oxford University Press, Oxford, 149 pp.", "Robertson, B. E. (1998) Systematics and paleoecology of the benthic Foraminiferida from the Buff Bay section, Miocene of Jamaica. Micropaleontology, 44, 1 - 266. https: // doi. org / 10.2307 / 1486062", "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", "Holbourn, A., Henderson, A. S. & MacLeod, N. (2013) Atlas of Benthic Foraminifera. Wiley-Blackwell, Oxford, 654 pp. https: // doi. org / 10.1002 / 9781118452493"]}