Neogloboquadrina dutertrei (d’Orbigny, 1839)

Ovechkina, Maria N., Bylinskaya, Marina E. & Uken, Ron, 2010, Planktonic foraminiferal assemblage in surface sediments from the Thukela Shelf, South Africa, African Invertebrates 51 (2), pp. 231-231 : 238

Neogloboquadrina dutertrei (d’Orbigny, 1839)

Figs 4E, 4F, 4H, 4I

Globigerina dutertrei: d’Orbigny 1839 a: 84 , pl. 4, figs 19–21; Brady 1879: 286; Banner & Blow 1960:

11, pl. 2, fig. 1.

Globigerina eggeri Rhumbler, 1901: 19 , text-fig. 20; Banner & Blow 1960: 11–12, pl. 2, figs 4a–c.

Globoquadrina dutertrei (d’Orbigny) : Parker 1962: 242, 244, pl. 7, figs 1–13; pl. 8, figs 1–4.

Neogloboquadrina dutertrei dutertrei (d’Orbigny) : Rögl & Bolli 1973: 570, pl. 9, figs 3, 6, pl. 10, figs

1–10, pl. 17, fig. 12.

Neogloboquadrina dutertrei (d’Orbigny) : Saito et al. 1981: 111, pl. 36, figs 1a–c, 2; Cimerman & Langer

1991: 57, pl. 60, fig. 1.

Test variable in size, usually medium, a medium-height trochospire with 4–6 subspherical to radially slightly flattened chambers in the final whorl. Chambers increase slowly in size as added, sutures depressed.Aperture a wide and deep opening directly into umbilicus. Remarks:A few individuals with a lower trochospire and more umbilical aperture were found ( Figs 4F, 4I ) in our material. These forms may be identified as N. eggeri ( Rhumbler, 1901) . Saito et al. (1981) separate these species on the basis of a higher spire in N. dutertrei , but Kennett and Srinivasan (1983) suppose that N. eggeri is a junior synonym of N. dutertrei . We tend to agree with the latter opinion at this stage.

N. dutertrei differs from N. incompta in having a bigger and less compact test, and in having more chambers in the final whorl.

Distribution: Equatorial and tropical waters. A common species in our material.

Figures

Fig. 4. (A–C) Globorotalia inflata (d’Orbigny, 1839), sample 26; (D, G) Neogloboquadrina incompta, sample 15; (E, H) N.dutertrei (d’Orbigny, 1839),sample 30; (F,I) N.dutertrei, a low trochospiral specimen with more umbilical aperture from sample 30.