Quinqueloculina d’Orbigny 1826

Mamo, Briony L., 2016, Benthic Foraminifera from the Capricorn Group, Great Barrier Reef, Australia, Zootaxa 4215 (1), pp. 1-123 : 34-35

Quinqueloculina d’Orbigny 1826

Quinqueloculina sp. cf. Q. agglutinans d’Orbigny 1839 ( Fig. 7 :19, 20; 8:1, 2)

Remarks. The ovate, quinqueloculine test, irregularly agglutinated walls, only slightly depressed sutures, a terminal aperture that often forms a slight neck and a bifurcate tooth ( Fig. 7 :19; 8: 2) suggests an affinity with Quinqueloculina agglutinans . However, the type material of d’Orbigny (1839, pl. 12, figs 11–13) and other published examples of this taxon exhibit a range of slightly differing morphologies. Compared to the original illustrations of Q. agglutinans d’Orbigny’s (1839, pl. 12, figs 11–13), d’Orbigny’s material shows a terminal aperture which sits on a more developed neck, the aperture is not ovoid but rather circular and the tooth is not visible. Instead there is a dentate lip with radial grooves. Le Calvez’s (1977) re-examination and illustrations of d’Orbigny’s topotype material and elected lectotype show specimens with a produced, elongate aperture with an everted peristomal rim that closely matches the aperture of the CG specimens. According to Parker (2009, p. 175) the topotypes illustrated by Bock et al. (1971) also conform to the same distinct apertural style.

This variation in test form has led to uncertainty in assigning CG specimens to this species. The slightly more elongate test and profile is also similar to Quinqueloculina bidentata d’Orbigny 1839 as illustrated in Le Calvez’s (1977 pl. 7, figs 1, 2) micrographs of d’Orbigny’s (1839) lectotype and topotype material. However, the original and subsequent re-description of Q. bidentata by Le Calvez (1977) also illustrates a very different quadrilateral aperture with a short bifid tooth. Parker (2009) argues that Q. bidentata has a distinctly more quadrate test chamber shape and a more truncated periphery in comparison to Q. agglutinans .

Specimens identified as Q. bidentata by Cushman (1921b) from Aua Reef, Samoa, are described as having a truncated periphery although the test is agglutinated with coarse grains and the aperture has a thickened lip with a long, thin tooth with a bifid tip.

Hatta & Ujiié (1992b) assigned specimens from the southern Ryukyu Island Arc to Q. bidentata , largely following the work of Cushman (1921b). These specimens also have a coarsely agglutinated test with a truncated periphery, an aperture with a distinctly thickened lip and an aperture featuring a long thin tooth that occasionally has a bifid tip.

Specimens from New Zealand assigned to Q. agglutinans by Hayward et al. (1999) show a more stout test with a rounded periphery and a rounded aperture with very thin lip and a much shorter tooth. In cross section the apertural shape of these specimens are very similar to the original illustrations of this species by d’Orbigny (1839) but still differs in dentition.

The specimens assigned to Q. agglutinans from New Caledonia by Debenay (2012) and tentatively assigned by Parker (2009) from Ningaloo Reef display significant resemblance to the specimens of Cushman (1921b) and Hatta & Ujiié (1992b). However, the specimens from Ningaloo Reef do not have a truncated periphery and are not strongly quadrate in cross-section and specimens from New Caledonia are only somewhat truncated.

Specimens from the CG are coarsely agglutinated with an elongate aperture possessing a peristomal lip and a long single tooth with a bifid tip. The cross sectional shape shows more rounded chamber peripheries although the terminal aperture on the CG specimens sits at a steeper angle compared to the specimens illustrated by Cushman (1921b), Hatta & Ujiié (1992b), Parker (2009) and Debenay (2012). Quinqueloculina agglutinans differs from other quinqueloculine species collected from the CG most specifically through its coarsely agglutinated test and its elongate aperture with peristomal lip and distinctly long single tooth with bifid tip.

This species has a Pacfic and Caribbean distribution (Cuba—d’Orbigny 1839; Florida—Bock et al. 1971; Samoa—Cushman 1921b; Ryukyu Island Arc—Hatta & Ujiié 1992b; New Zealand and Chatham Islands— Hayward et al. 1999, Hayward 1995; southwestern lagoon of New Caledonia—Debenay 2012; Ningaloo Reef— Parker 2009).

Distribution within study area. Quinqueloculina agglutinans was collected from all reefs except Sykes Reef. With an average of three specimens collected per site, this species was most abundant at site 25 in One Tree Lagoon 1 and site 3 of Transect 3 on Heron Reef flat. The abundance of Q. agglutinans was also low in Heron Lagoon with most sites only containing one to two specimens.

Figures

FIGURE 7. (Unless otherwise specified all scale bars = 100 µm). 1 – 2. Spiroloculina foveolata Egger, 1893, QM # G 465816 from OTI 36. 1. Lateral view. 2. Oral view. 3 – 4. Spiroloculina sp. 1, QM # G 465834 from OTI 39. 3. Lateral view. 4. Peripheral view. Scale bars = 200 µm. 5 – 6. Pitella haigi Langer, 1992, QM # G 465806 from T 2 – 3. 5. Lateral view. 6. Oral view. 7 – 8. Siphonaperta crassa Vella, 1957, QM # G 466065 from T 3 – 6. 7. Lateral view. 8. Oral view. 9 – 10. Siphonaperta distorqueata (Cushman, 1954), QM # G 465912 from OTI 52. 9. Lateral view. 10. Oral view. 11 – 14. Hauerina earlandi Rasheed, 1971, scale bars = 50 µm. 11 – 12. QM # G 465987 from OTI 39 lateral (11) and peripheral (12) views. 13 – 14. QM # G 466103 from OTI 51 lateral (13) and oral (14) views. 15 – 18. Hauerina pacifica Cushman, 1917. 15 – 16. QM # G 465899 from ST / HW 10. Lateral view (15) and close-up oral view (16). Scale bar = 10 µm. 17 – 18. QM # G 466125 from T 1 – 8. 17. Lateral view. 18. Oral view. 19 – 20. Quinqueloculina cf. Q. agglutinans d’Orbigny, 1839, QM # G 465807 from T 2 – 3, lateral view (19) and peripheral view (20).