Amphistegina lessonii d’Orbigny, 1826

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 : 107

Amphistegina lessonii d’Orbigny

Figures 31.15, 31.16

1826 Amphistegina lessonii d’Orbigny , p. 304, pl. 17, figs. 1—4.

1865 Amphistegina lessonii d’Orbigny — Parker, Jones, and Brady, p. 34, pl. 3, figs. 91, 92.

1941 Amphistegina lessonii d’Orbigny — LeRoy (Part 1), p. 41, pl. 3, figs. 18, 19.

1977 Amphistegina lessonii d’Orbigny — Larsen, pp. 274, 275, pl. 1, figs. 1—9.

1987 Amphistegina lessonii d’Orbigny — Loeblich and Tappan, pl. 677, figs. 3—5.

1988 Amphistegina lessonii d’Orbigny — Marle, p. 139, pl. 1, fig. 5.

1992 Amphistegina lessonii d’Orbigny — Hatta and Ujiié (b), p. 195, pl. 42, fig. 4.

1994 Amphistegina lessonii sensu Parker, Jones, and Brady — Jones, pp. 109, 110, pl. 111, figs. 2, 4—7.

1994 Amphistegina lessonii d’Orbigny — Loeblich and Tappan, pp. 156, 157, pl. 340, figs. 1—9.

1995 Amphistegina lessonii d’Orbigny — Ujiié, pp. 68, 69, pl. 11, fig. 3.

Remarks. This large form is a typical shallowwater species. The present specimens are small,

up to 0.34 mm in diameter, and have probably been transported by gravity currents from shallower areas.

Occurrence. A single specimen each from two samples of the Minebari Formation.

Figures

FIGURE 31. Family Planulinidae, Cibicididae, Epistomariidae, Amphisteginidae, and Nonionidae. All scale bars = 0.1mm. 1, 2. Planulina retia Belford, 1: MPC-26416 from sample 2 (Minebari Formation, PL5); 2: MPC-26417 from sample 5-2 (Minebari F., PL5). 3, 4. Cibicides refulgens de Montfort, 3: MPC-26197 from sample 2-2 (Minebari F., PL5); 4: MPC-26198 from sample 14-2 (Yonahama F., PL4). 5. Cibicides tenuimargo (Brady), MPC-26199 from sample 4-2 (Minebari F., PL5); stripe pattern on the dorsal side implies attached material. 6, 7. Fontbotia wuellerstorfi (Schwager), 6: MPC-26272 from sample MK01 (Yonahama F., PL2); 7: MPC-26273 from sample MK02A (Minebari F.,PL5).8, 9. Lobatula lobatula (Walker and Jacob), 8: MPC-26367 from sample 5 (Minebari F., PL5); 9: MPC-26368 from sample 5-2 (Minebari F., PL5). 10, 11. Dyocibicides biserialis Cushman and Valentine, 10: MPC-26224 from sample 2-2 (Minebari F., PL5); 11: MPC-26225 from sample 3-2-up-sand (Onogoshi F., PL1). 12—14. Pseudoeponides japonicus Uchio, 12: MPC-26430 from sample 14 (Yonahama F., PL4); 13: MPC-26431 and 14: MPC-26548 from sample MK02B (Minebari F., PL5); arrows in 14 shows slit opening along dorsal sutures. 15, 16. Amphistegina lessonii d'Orbigny, 15: MPC-26123 from sample 2 (Minebari F., PL5); 16: MPC-26124 from sample 2-2 (Minebari F., PL5); all specimens of this study are juveniles. 17, 18. Nonion japonicum Asano, 17: MPC-26392 from sample 5-2 (Minebari F., PL5); 18: MPC-26393 from sample 11 (Onogoshi F.,?PL1). 19, 20. Nonionellina labradorica (Dawson), 19: MPC-26394 from sample 1-2 (Minebari F., PL5); 20: MPC-26395 from sample MK02B (Minebari F., PL5). 21, 22. Pseudononion cuevasensis Saunder and Müller-Merz, 21: MPC-26438 from sample 10 (Onogoshi F., PL2); 22: MPC-26439 from sample MK02B (Minebari F., PL5). 23, 24. Pseudononion subcostatum Fujita and Ito, 23: MPC- 26440 from sample 14-2 (Yonahama F., PL4); 24: MPC-26441 from sample MK02B (Minebari F., PL5).