Spiroplectinella wrightii (Silvestri)

Hanagata, S & Nobuhara, T, 2015, Illustrated guide to Pliocene foraminifera from Miyakojima, Ryukyu Island Arc, with comments on biostratigraph, Palaeontologia Electronica (Cambridge, England) 33 (8), pp. 1-142 : 14-16

Spiroplectinella wrightii (Silvestri)

Figures 6.7, 6.8

1903 Spiroplecta wrightii Silvestri , p. 59, text-figs. 1—6.

1953 Spiroplectammina higuchii Takayanagi , p. 27, pl. 4, fig. 1.

1968 Spiroplectammina sagittula (Soldani) — Huang, pl. 12, fig. 3 (non Polymorpha sagittulae Soldani, 1791 = Textularia sagittula Soldani var. soldanii Fornasini, 1883 , pp. 183, 184, pl. 2, fig. 2).

1987 Spiroplectinella wrightii (Silvestri) — Loeblich and Tappan, pl. 120, pl. 1—10.

1990 Spiroplectammina higuchii Takayanagi — Akimoto, p. 213, pl. 14, fig. 4.

1994 Spiroplectinella wrightii (Silvestri) — Loeblich and Tappan, p. 20, pl. 15, figs. 15— 18.

2002 Spiroplectinella higuchii (Takayanagi) — Akimoto, Matsui, Shimokawa, and Furukawa, p. 3, pl. 1, fig. 1.

2002 Spirorutilis sp. — Kaminski, Aksu, Box, Hiscott, Filipescu, and Al-Salameen, p. 195, pl. 1, figs. 3, 4.

2012 Spiroplectinella sagittula s.l. (Defrance) — Milker and Schmiedl, p. 34, figs. 9.19— 9.21 (non Textularia sagittula Defrance, 1824, p. 177 ).

Diagnosis. Triangular, of moderate size for the genus, chambers not inflated, increasing slowly as added, sutures depressed, periphery bluntly angled, wall finely agglutinated, aperture low arched at base of final chamber.

Remarks. Textularia saggitula Defrance (or d’Orbigny) has been referred to as Spiroplectammina sagittula by many workers, although it is the type species of the genus Textularia and differs from S. wrightii ( Loeblich and Tappan, 1987;

Kaminski et al., 2002). Spiroplectammina higuchii is regarded as a synonym.

Occurrence. Common in the Yonahama and Minebari formations.

Figures

FIGURE 6. Family Hormosinidae, Ammosphaeroidinidae, Spiroplectamminidae, Duquepsamminidae, Verneuilinidae, and Eggerellidae. All scale bars = 0.1mm, unless otherwise indicated in 2.1, 23.1, 26.1 as 1mm-line. 1, 2. Rhabdammina sp., 1: MPC-26061, 2: MPC-26062, both from sample 7 (Yonahama Formation, PL4), broken specimens. 3. Hormosinella distans (Brady), MPC-26051, from sample 15 (Yonahama F., PL3), depressed specimen. 4. Reophax sp., MPC-26060, from sample 7 (Yonahama F., PL4). 5, 6. Ammosphaeroidina sphaeroidiniformis (Brady); 5: MPC-26033 from sample 6 (Yonahama F., PL2); 6: MPC-26034, from sample 6-2 (Yonahama F., PL2). 7, 8. Spiroplectinella wrightii (Silvestri), 7: MPC-26065 from sample 6-2 (Yonahama F., PL2); 8: MPC-26066 from sample MK02A-2 (Minebari F., PL5). 9, 10. Duquepsammia bulbosa (Cushman), 9: MPC-26041 from sample 8 (Yonahama F., PL4), 10: MPC-26042 from sample 15 (Yonahama F., PL3). 11, 12. Trochammina sp., 11: MPC-26077, laterally depressed specimen, 12: MPC26078, vertically depressed specimen, both from sample 7 (Yonahama F., PL4). 13, 14. Gaudryina arenaria Galloway and Wissler, 13: MPC-26045 from sample 6-2 (Yonahama F., PL2); 14: MPC26046 from sample 17 (Yonahama F., PL2). 15, 16. Gaudryina sp.A., 15: MPC-26047 from sample 3-2-low-silt (Onogoshi F., PL1); 16: MPC-26048 from sample 11 (Onogoshi F.,?PL1). 17, 18. Gaydryinella cf. japonica Asano, 17 MPC-26049, 18 MPC- 26050, both from sample 18 (Oura F.,?PL1). 19, 20. Eggerella bradyi (Cushman), 19: MPC-26043 from sample 14-2 (Yonahama F., PL4); 20: MPC-26044 from sample 15 (Yonahama F., PL3). 21, 22. Karreriella bradyi (Cushman), 21: MPC-26052 from sample 2 (Minebari F., PL5); 22: MPC-26053 from sample MK02A (Minebari F., PL5). 23, 24. Martinottiella communis (d'Orbigny), 23: MPC-26054 from sample 3 (Onogoshi F., PL1); 24: MPC-26055 from sample 3- 2-low-silt (Onogoshi F., PL1). 25, 26. Martinottiella victorensis (Cushman), 25: MPC-26056 from sample 6-2 (Yonahama F., PL2); 26: MPC-26057 from sample 16 (Yonahama F., PL3).