Rudigaudryina Cushman & McCulloch 1939

Mamo, Briony L., 2016, Benthic Foraminifera from the Capricorn Group, Great Barrier Reef, Australia, Zootaxa 4215 (1), pp. 1-123 : 16-17

Rudigaudryina Cushman & McCulloch 1939

Rudigaudryina minor ( Chapman 1902) ( Fig. 3 :18–20; Fig. 4 :1–3)

1902 Haddonia minor Chapman , p. 384, pl. 36, figs 1–2.

1987 Haddonia minor Chapman ; Baccaert, p. 11, pl. 3, fig. 5; pl. 4, figs 1–5. 2001 Rudigaudryina minor (Chapman) ; Lobegeier, p. 285, pl. 3, figs 5–9. 2009 Rudigaudryina minor (Chapman) ; Parker, p. 32, fig. 26a–c, 27a–f.

Description. Rudigaudryina is typified by an early triserial test stage (at least in microspheric forms) that becomes biserial and then in adult forms gains an irregular chamber arrangement with more inflated and broad final chambers ( Fig. 3 :18–20). Walls are finely arenaceous, firmly and smoothly cemented. Aperture is generally terminal or found near the base of the final chamber, rounded and occasionally with a slight lip ( Cushman & McCulloch 1939; Loeblich & Tappan 1987; Parker 2009).

Rudigaudryina minor ( Chapman 1902) is characterised as either a free ( Fig. 3 :18–20; Fig. 4 :1–3) or an attached test by its earlier segments and a slight horse-shoe shaped aperture ( Fig. 4 :2).

Remarks. These specimens were assigned to this species due to their initial triserial stage which becomes biserial, and often irregular and inflated chamber arrangement. Also, due to their sometimes attached, agglutinated test and slightly horse-shoe shaped terminal aperture.

The distribution of R. minor is circumtropical (Funafuti Tuvalu, Galapagos Islands , Bay of Jakarta and the Great Barrier Reef—Parker 2009) and is reported as both a free and attached species to Halimeda algae and larger carbonate reef rubble. Due to this, the characteristic triserial stage of this species can be difficult to discern in some instances ( Parker 2009).

Distribution within study area. Rudigaudryina minor was collected from all areas across both reef flat and lagoons in relatively low numbers (1– 14 specimens per sample). It was most abundant in One Tree Lagoon 2 and along Transect 1, which runs along the boundary between the inner and outer reef flats at Heron Island.

Figures

FIGURE 3. (Unless otherwise specified all scale bars = 100 µm). 1 – 3. Reophax nana Rhumbler, 1911, QM # G 465920 from WL 7. 1. Lateral view, scale bar = 200 µm. 2. Oblique oral view, scale bar = 200 µm. 3. Close-up oral view, scale bar = 20 µm. 4. Ammobaculites sp. 1, QM # G 465924 from WL 15. Lateral view. 5 – 12. Rotaliammina chitinosa (Collins, 1958). 5 – 6. QM # G 466031 from T 2 – 5, spiral (5) and close-up spiral (6) views. Scale bar for 5 = 1 mm. 7 – 8. QM # G 465776 from ST / HW 2, spiral (7) and close-up spiral (8) views. Scale bar for 7 = 500 µm. 9 – 10. QM # G 466022 from T 1 – 4 spiral (9) and close-up spiral (10) views. Scale bar for 9 = 500 µm. 11. QM # G 465940 from OTI 20, spiral view. 12. QM # G 466054 from CHANNEL, umbilical view. Scale bar = 50 µm. 13 – 14. Trochammina cf. T. subconica (Parr, 1950), QM # G 465937 from OTI 50. 13. Lateral view. 14. Oral view. 15 – 16. Bdelloindina cf. B. aggregata Carter, 1877, QM # G 466025 from T 1 – 2. 15. Lateral view, scale bar = 200 µm. 16. Close-up lateral view, scale bar = 50 µm. 17. Haddonia torresiensis Chapman, 1898, QM # G 465906 from ST / HW 2, lateral view. Scale bar = 500 µm. 18 – 20. Rudigaudryina minor (Chapman, 1902). 18. QM # G 465960 from OTI 50, lateral view. Scale bar = 500 µm. 19. QM # G 465891 from ST / HW 8, lateral view. Scale bar = 500 µm. 20. QM # G 465826 from OTI 39, lateral view. Scale bar = 500 µm.

FIGURE 4. (Unless otherwise specified all scale bars = 100 µm). 1 – 3. Rudigaudryina minor (Chapman, 1902), 1. QM # G 465826 from OTI 39, side view. Scale bar = 500 µm. 2 – 3. QM # G 465830 from OTI 39 lateral view (2) and oral view (3). Scale bar for 2 = 200 µm. 4 – 5. Siphoniferoides siphonifera (Brady, 1881), QM # G 465792 from T 2 – 1. 4. Lateral view, scale bar = 200 µm. 5. Oral view. 6 – 7. Sahulia barkeri (Hofker, 1978), QM # G 465827 from OTI 39. 6. Aboral view. 7. Lateral view. 8 – 13. Textularia agglutinans d’Orbigny, 1839. 8 – 9. QM # G 465957 from OTI 43 lateral (8) and oral (9) views. Scale bar for 8 = 50 µm. Scale bar for 9 = 20 µm. 10 – 11. QM # G 465959 from OTI 50 lateral (10) and oral (11) views. Scale bar for 10 = 200 µm. 12 – 13. QM # G 465903 from ST / HW 10 lateral (12) and oral (13) views. 14 – 16. Textularia candeiana d’Orbigny, 1839, QM # G 465966 from CHANNEL. 14 Lateral view. 15. Peripheral view, scale bar = 200 µm. 16. Oral view. 17 – 20. Textularia jparkeri n. sp. 17 – 18. QM # G 465953 from CHANNEL. 17. Lateral view, scale bar = 500 µm. 18. Oral view, scale bar = 200 µm. 19 – 20. QM # G 466055 from CHANNEL, lateral (19) and oral (20) views. Scale bars = 200 µm.