Spincterules sp. A

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 : 34

Spincterules sp. A

Figure 12.6

Description. Test planispiral, of moderate size (about 0.5 mm in diameter); bilaterally compressed and with near-parallel sides; six chambers in last whorl; sutures curve backwards; umbilicus slightly raised by thickened wall; surface smooth, flushed; suture slightly raised but obscured by abrasion; aperture radiate.

Remarks. Mainly due to poor preservation, we were unable to identify this to species level.

Occurrence. A single specimen from the Minebari Formation.

Figures

FIGURE 12. Family Vaginulinidae. All scale bars = 0.1mm, unless otherwise indicated. 1, 2. Saracenaria aff. akitaensis Iwasa and Kikuchi, 1: MPC-26485 from sample 2 (Minebari Formation, PL5); 2: MPC-26486 from sample 17 (Yonahama F., PL2). 3. Saracenaria altifrons (Parr), MPC-26487 from sample 15 (Yonahama F., PL3). 4, 5. Saracenaria italica Defrance, 4: MPC-26488, 5: MPC-26489, both from sample 2-2 (Minebari F., PL5). 6. Spincterules sp.A, MPC-26507 from sample 5-2 (Minebari F., PL5). 7, 8. Amphicoryna hispida (d'Orbigny), 7: MPC-26118 from sample 3-2-low-silt (Onogoshi F., PL1); 8: MPC-26119 from sample MK01 (Yonahama F., PL2). 9—11. Amphicoryna separans (Brady), 9: MPC-26120 from sample 3-2-low-silt (Onogoshi F., PL1); 10: MPC-26121 from sample 14-2 (Yonahama F., PL4), 11: MPC-26122 from sample 5 (Minebari F., PL5). 12, 13. Astacolus japonicus (Asano), 12: MPC- 26132 from sample 2 (Minebari F., PL5); 13: MPC-26133 from sample 6-2 (Yonahama F., PL2). 14. Astacolus insolitus (Schwager), MPC-26131 from sample 15 (Yonahama F., PL3). 15, 16. Hemirobulina aff. obesa (Cushman), 15: MPC-26546 from sample 16 (Yonahama F., PL3); 16: MPC-26315 from sample MK01 (Yonahama F., PL2). 17. Hemirobulina aff. uedai (Asano), MPC-26316 from sample 15 (Yonahama F., PL3). 18. Vaginulinopsis sublegumen Parr, MPC-26528 from sample 3 (Oura F., PL1).