Operculina complanata ( Defrance, 1822 )

Gedik, Fatma & Karadenizli, Levent, 2021, Oligocene larger benthic foraminifera and sedimentation of the Burdur Basin, SW Anatolia, Turkey, Geodiversitas 43 (13), pp. 377-389 : 383

Operculina complanata ( Defrance, 1822) ( Fig. 5A, B )

Lenticulites complanata Defrance, 1822: 453 .

Operculina complanata – Souaya 1963: pl. 53, figs 1, 2. — Cherif 1980: pl. I, figs 4, 10; pl. II, figs 1, 5. — Abdelgany 2002: pl. II, figs 2-4. — Sirel 2003: pl. III, figs 1-9. — Gedik 2008: pl. 2, figs 6-10.

REMARKS

The test is thin, bilateral and symmetric. Its diameter ranges from 2.5 to 2.9 mm, and the thickness from 0.4 to 1.8 mm. The test is planispiral and evolute, with numerous narrow chambers in many rapidly expanding whorls, so that the height of the chambers may be five times the width of the chambers ( Fig. 5A, B ). The proloculus is spherical and small (90 µ diameter).

Figures

FIG. 5. — A, B, Operculina complanata (Defrance, 1822); A, equatorial section, İl-6C/2; B, incomplete equatorial section, İl-6B/2; C, J, Nummulites fichteli Michelotti, 1841; C, external view, İl-6C/3; J, axial section, megalospheric form, İl-6A; D-G, Nephrolepidina praemarginata (Douvillé, 1908); D, axial section, İl-6A; E, external view, İl-6B/4; F, axial section, megalospheric form, İl-6C/1; G, axial section, İl-6B/2. H, I, Eulepidina sp., subaxial sections, İl-6A, İl-6B/5. Scale bars: A, 1 mm; B, D-G, L, 0.5 mm; C, I, J, 2 mm.