(d'Orbigny, 1839)
Non-spinose, with 4.5 to 7 subglobular chambers in last whorl. Surface texture determined by regular pore pattern. Last normal chamber usually broader than previous ones, positioned on top of first and penultimate chamber of last whorl. Kummer chambers often present. Gametogenic calcification occurs regularly, calcite crust developed below 15°C.
Ref.: Kennett (1976), Bouvier-Soumagnac and Duplessy (1985), Srinivasan and Kennett (1976), Thiede and Jünger (1992), Kroon and Darling (1995), Ravelo and
Distribution: Frequent in the eastern tropical to temperate South Atlantic, less abundant in the subtropics. In the eastern South Atlantic, highest concentrations of N. dutertrei are recorded off the African coast. Previous studies indicate that this species reaches peak concentrations where the thermocline is shallow and the chlorophyll maximum is located between 25 and 50 m (Fairbanks and Wiebe, 1980; Fairbanks et al., 1982; Ravelo et al., 1990; Kemle-von Mücke, 1994). Both conditions are met in the Guinea Basin, which may explain its high local abundances. On the sea floor it exceeds 10% of the entire foraminiferal thanatocoenosis, reaching 25% in the Guinea Basin (Van Leeuwen, 1989). In the North Atlantic this species occurs in tropical as well as subtropical regions, and its depth stratification is tied to the physico-chemical and biological properties of the upper water column (e.g., thermocline depth, chlorophyll maximum). As shown experimentally, it forms a calcite crust when the water temperature drops below 15°C (Hemleben et al., 1989).
Remark: = Globoquadrina dutertrei