Crommium, Cossmann, 1888

Islamoğğlu, Yeşşim, Dominio, Stefano & Kowalke, Thorsten, 2011, Early Eocene Caenogastropods (Mollusca, Gastropoda) from Haymana-Polatl Basin, Central Anatolia (Turkey): taxonomy and palaeoecology, Geodiversitas 33 (2), pp. 303-330 : 312

“ Crommium ” sp. 2 ( Fig. 6P, R )

MATERIAL EXAMINED. — Two specimens, MTA- Y. İ.-2007 -16 and 17.

LOCALITY AND HORIZON. — Grey siltstone-mudstone, KIrkkavak Formation (Macunköy: sample G4).

DESCRIPTION

High and slightly concave conical spire, with high and convex whorls. The last whorl is globular with a stepped outline, its upper surface somewhat flattened. The aperture is narrow and ovate. The apical angle is wider (between 105-107), HL/HT is shorter (0.80-0.82), LT/HT is 0.89-0.96 (Appendix 1).

REMARKS

“ Crommium ” sp. 2 differs from “ Crommium ” sp. 1 by concave stepped spiral whorls and a shorter body whorl.

Figures

FIG. 6. — Caenogastropods (deposited in the repositories of the General Directorate of Mineral Research and Exploration, Ankara): A, Cerithium puigcercosensis (Cossmann,1897) n. comb.;B-F, Vicinocerithium cf.subacutum (d’Orbigny,1850); G, S, Bellatara ankaraensis n. sp., holotype;H, I, Tympanotonos turris (Deshayes,1833); J, Cerithium cf.anguloseptum Rauff,1884; K-M, Gantechinobathra vulcani (Brongniart, 1823); P-R, “Crommium” sp. 2. Scale bars: 1 cm.