Orbulina universa d'Orbigny 1839

Orbulina universa d’Orbigny, 1839 Pl. 8, fig. 7

Orbulina universa d’Orbigny, 1839, pl. 28, fig. 2; LeRoy, 1948, p. 501, fig.1a; Kennett & Srinivasan, 1983, p. 86, pl. 20, fig. 4–6; Kender et al., 2008, p. 522, pl. 28, fig. 2.

Description: The test surface is spinose and covered with many perforations of different sizes across the entire test. The test is spherical, which may enclose an earlier globigerinid stage. There is no single large primary aperture.

Remarks: The relative abundances of Orbulina universa form a minor component (<10%) of the planktic foraminiferal assemblage in core 2658. In the deeper cores (2670 and 2682), the relative abundances are mostly at <1% in the middle Miocene component of the cores. The tests are relatively small to moderate in size, measuring up to 0.5 mm in diameter.

Global stratigraphic range: Orbulina universa is an extant species with its first appearance datum in the middle Miocene (Langhian) (Kennett & Srinivasan, 1983; Jones, 1994).

Environmental preferences: This species is cosmopolitan and occurs widespread (BouDagher-Fadel, 2015), but has been documented to be more adapted to subtropical conditions, preferring warmer waters (Zachariasse et al., 1997; Gallagher et al., 2001; Kucera, 2007; Drinia et al., 2008; Hemleben et al., 1990).

Regional occurrence: Orbulina universa is stratigraphically and spatially widespread along the southern and western margin of Africa. This species has been documented to occur in Miocene-aged strata of the Congo Basin (Kender, 2007) to the northern Namibian outer continental shelf, south of the Kunene River mouth (this study) and the southwestern shelf of South Africa (Compton et al., 2004). Wefer et al. (1998) reported the species to occur on the slope between central Namibia and offshore of the Orange River during the Pliocene and Pleistocene.