Hemirobulina aff. obesa (Cushman)

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 : 35

Hemirobulina aff. obesa (Cushman)

Figures 12.15, 12.16

Compared with:

1923 Marginulina glabra var. obesa Cushman , p. 128, pl. 37, fig. 1.

1990 Marginulina cf. obesa (Cushman) — Ujiié, pp. 20, 21, pl. 6, figs. 2, 3.

1994 Marginulinopsis sp. — Loeblich and Tappan, p. 69, pl. 124, figs. 16, 17.

Remarks. This species closely resembles Hemirobulina obesa in general test shape, whereas test length of all specimens of in the present material is approximately 0.3 mm, i.e., much smaller than H.

obesa which attains lengths of up to 3 mm.

Occurrence. Sporadic in the Yonahama and Minebari formations.

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).