Globigerinoides ruber (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 : 245

Globigerinoides ruber (d’Orbigny, 1839)

Figs 9A–E

Globigerina rubra: d’Orbigny 1839 a: 82 , pl. 4, figs 12–14; Brady 1879: 286; Banner & Blow 1960: 19,

pl. 3, figs 8a–b.

Globigerinoides ruber (d’Orbigny) : Parker 1962: 230, 232, pl. 3, figs 11–14, pl. 4, figs 1–10; Todd 1965:

63, pl. 25, fig. 6; Pflaumann & Krasheninnikov 1978: 889, pl. 3, figs 1–6; Saito et al. 1981: 59, pl.

15, figs 1a–d; Bolli & Saunders 1985: 196, figs 20.1, 2, 6; Cimerman & Langer 1991: 58, pl. 60, fig.

9; Loeblich & Tappan 1994: 107, pl. 203, figs 1–9; pl. 206, figs 10–12; Basov & Krasheninnikov

1995: pl. V, figs 3, 4; Bylinskaya et al. 2002: 128, pl. III, figs 6, 7.

Test small to medium, variable, low or high trochospiral, with 3 characteristic globular chambers in the final whorl and a drop-shaped primary aperture situated symmetrically above suture between two previous chambers. Secondary supplementary apertures are smaller openings on the spiral side. Test may have pink to red pigmentation.

Remarks: The pink-colored forms have not been found in surface sediments of the Indo-Pacific area ( Bé & Hutson, 1977; Saito et al. 1981), where they have disappeared at about 120 ka ( Thompson et al. 1979). Many specimens in the Indo-Pacific area which could be considered pink varieties have an early whorl or two of light pink chambers and gradually become white in later chambers (Saito et al. 1981).

In our material we also found seven individuals that show aberrant features ( Figs 9D, 9E ; Table 2). Their tests are medium to large, medium–high trochospiral, very loosely embracing, with 4–5 subglobular slightly flattened chambers in the final whorl. The last chamber is completely detached from the previous whorl and is connected with the penultimate chamber only. The test wall is spinose, strongly perforated. The primary aperture is umbilical, in the form of a broad and deep arch. Secondary apertures are smaller, semicircular or drop-shaped. This form was mentioned as G. ruber forma helicina (Saito et al. 1981: 165, pl. 56, fig. 7), but coiling in our material is markedly looser than illustrated in the aforementioned work.

Distribution: Equatorial to temperate waters, most abundant in the tropical and subtropical areas; it is indicative of warm-water conditions. The species is abundant in our material.

Figures

Fig. 9. (A, B) Globigerinoides ruber (d’Orbigny, 1839), sample 22; (C) G. ruber, sample TB34; (D, E) G. ruber (aberrant form),sample 8; (F, G) Sphaeroidinella dehiscens (Parker &Jones,1865), sample 30; (H) Orbulina universa (d’Orbigny, 1839), sample C.