Trilobatus sicanus

• Main Authors: Bergh, Eugene W., Compton, John S.
• Format: Text
• Language: unknown
• Published: Zenodo 2022
• Subjects: Biodiversity; Taxonomy; Chromista; Foraminifera; Globothalamea; Rotaliida; Globigerinidae; Trilobatus; Trilobatus sicanus; Curva; Palermo; Saunders; Trinidad; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.5281/zenodo.5840597; https://zenodo.org/record/5840597

Trilobatus sicanus (de Stefani, 1952) Pl. 8, fig. 4 Globigerinoides conglobata Cushman & Stainforth, 1945, pl. 13, fig. 6. ( Not Gs. conglobatus ). Globigerinoides sicana de Stefani, 1952, p.9. Praeorbulina sicana Bolli et al. , 1985, p. 199, fig. 24.7; Kender et al ., 2008, p. 522, pl. 27, fig. 6. Description : The test surface is macroperforate and cancellate. The test is globular and circular in cross section. The chambers are rounded, with slit-like apertures separating the chambers. Approximately half of the test is enveloped by the final chamber. The primary aperture appears as a narrow slit-like opening and supplementary apertures form along sutures on the spiral side of the test. Remarks: The relative abundances of G. bisphericus is trace (<1%) in samples of all three cores. The tests are small, measuring 0.3 mm in diameter. The likely ancestor of T. sicanus is T. bisphericus (Spezzaferri et al ., 2015). This species differs from its ancestor in its more enveloping final chamber, with more of the umbilicus being covered. Trilobatus sicanus is also considered to be intermediate between T. bisphericus and Praeorbulina curva (Bolli et al ., 1985). Environmental preferences: T. sicanus is identified as a subtropical to tropical species (BouDagher-Fadel, 2015). Global stratigraphic range : This species is an indicator species for the Miocene – Burdigalian to Langhian (Wade et al ., 2011; BouDagher-Fadel, 2015). Regional occurrence: T. sicanus has been identified in Miocene strata from the Congo Basin (Kender et al. , 2008) to the northern Namibian outer continental shelf, south of the Kunene River mouth (this study). : 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 pages 34-35, DOI: 10.11646/zootaxa.5091.1.1, http://zenodo.org/record/5840434 : {"references": ["De Stefani, T. (1952) Su alcune manifestazioni di idrocarburi in provincia di Palermo e descrizione di Foraminiferi nuovi. Plina, Palermo, 12 pp.", "Cushman, J. A. & Stainforth, R. M. (1945) The foraminifera of the Cipero marl formation of Trinidad. British West Indies. Cushman Laboratory for Foraminiferal Research, Special Publication, 14, 3 - 75.", "Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (1985) Plankton Stratigraphy. Cambridge University Press, Cambridge, 1032 pp.", "Kender, S., Kaminski, M. A. & Jones, R. W. (2008) Early to middle Miocene foraminifera from the deep-sea Congo Fan, offshore Angola. Micropalaeontology, 54, 477 - 568.", "Spezzaferri, S., Kucera, M., Pearson, P. N., Wade, B. S., Rappo, S., Poole, C. R., Morard, R. & Stalder, C. (2015) Fossil and genetic evidence for the polyphyletic nature of the planktonic foraminifera \" Globigerinoides \", and description of the new genus Trilobatus. PLoS One, 10, e 0128108. https: // doi. org / 10.1371 / journal. pone. 0128108", "BouDagher-Fadel, M. K. (2015) Biostratigraphic and geological significance of planktonic foraminifera. UCL Press, London, 306 pp. https: // doi. org / 10.2307 / j. ctt 1 g 69 xwk", "Wade, B. S., Pearson, P. N., Berggren, W. A. & Palike, H. (2011) Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale. Earth-Science Reviews, 104, 111 - 142. https: // doi. org / 10.1016 / j. earscirev. 2010.09.003"]}