Didacna subpyramidata Pravoslavlev, 1939

van de Velde, Sabrina, Yanina, Tamara A., Neubauer, Thomas A. & Wesselingh, Frank P., 2020, The Late Pleistocene mollusk fauna of Selitrennoye (Astrakhan province, Russia): A natural baseline for endemic Caspian Sea faunas, Journal of Great Lakes Research 46 (5), pp. 1227-1239 : 1234-1235

Didacna subpyramidata Pravoslavlev, 1939

( Fig. 5 : 2).

*1939 Didacna subpyramidata Pravoslavlev : 212, pl. 1, figs. 7–8.

1953 Didacna subpyramidata Pravoslavlev, 1939 – Fedorov: 122, pl. 9, figs. 4, 8, pl. 10, figs. 7–10.

1969 Didacna subpyramidata Pravoslavlev, 1939 – Vekilov: 83, pl. 14, figs. 1–4.

1983 Didacna subpyramidata Pravoslavlev, 1939 – Popov: 198, pl. 7, figs. 1–6.

2007 Didacna subpyramidata Pravoslavlev, 1939 – Nevesskaja: 908, pl. 13, figs. 13–18.

Dimensions – max. L 43.8 mm, H 39.5 mm.

Characterization – Large, high, trigonate-convex species with protruding beak; posterodorsal margin very steep and clearly delimited; the posterior ridge is sharp and massive. The species show 17–21 posterior ribs that are typically 2–3 times as wide as the interspaces. The ribs have a subangular to flat-square crosssection. Shells are thick and robust as is the hinge. Outline of juvenile shells is trigonate and very similar as Didacna emendata but with fewer ribs.

Ecology – Unknown (extinct).

Figures

Fig. 5. Overview of the Cardiidae.(1) Didacna subcrassa; (a) RGM-1309816 LV;(b) RGM-1309815 RV.(2) Didacna subpyramidata; (a) RGM-1309797 LV; (b) RGM-1309814 RV. (3) Didacna subcatillus; (a) RMG-1309819 LV; (b) RMG-1309820 RV. (4) Didacna emendata; (a) RGM-1309799 LV; (b) RGM-1309798 RV. (5) Didacna ebersini; A (a) RGM- 1309817 LV; (b) RGM-1309818 RV. (6) Didacna cristata; (a) RGM.1309800 LV; (b) RGM.1309801 RV. Scale bars = 1 cm.