Globoquadrina dehiscens ( Chapman, Parr & Collins, 1934 )

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 30

Globoquadrina dehiscens ( Chapman, Parr & Collins, 1934)

Pl. 7, figs. 2–3

Globorotalia dehiscens Chapman et al., 1934, p. 569 , pl. 11, fig. 36.

Globoquadrina dehiscens dehiscens Jenkins, 1960 . P. 354, pl. 3, fig. 3a–c.

Globoquadrina dehiscens Jenkins, 1960, p. 355 , pl. 3, fig. 4a–c; Kennett & Srinivasan, 1983, p. 184, pl. 45, figs. 7–9; Kender et al., 2008, p. 521, pl. 29, fig. 1.

Description: The test surface is cancellate. The test is trochospiral and roughly quadrate in outline. There are four chambers visible in the final whorl. The sutures between chambers are strongly incised. The spiral side is nearly flat. The aperture is dentate and central to the four final chambers.

Remarks: The relative abundances of Globoquadrina dehiscens form a minor component (<10%) of the planktic foraminiferal assemblage in core 2658. In the deeper cores (2670 and 2682), the relative abundances of Globoquadrina dehiscens are below 5%. The tests are relatively small to moderate in size, measuring up to 0.5 mm in diameter.

Environmental preferences: This species has been associated with tropical to temperate surface waters ( Kennett & Srinivasan, 1983; Bicchi et al., 2003).

Global stratigraphic range: Globoquadrina dehiscens has been documented to occur in strata dated to the early to late Miocene – Aquitanian to Messinian (Kennett & Srinavasan, 1983; Wade et al., 2011).

Regional occurrence: This species has been recorded 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).