Didacna emendata Popov, 1983

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 : 1233

Didacna emendata Popov, 1983

( Fig. 5 : 4).

*1983 Didacna delenda emendata Popov : 174, pl. 6, figs. 8–20.

2007 Didacna emendata Popov, 1983 – Nevesskaja: 915, pl. 15, figs. 22-23.

Dimensions – L 21.2 mm, H 18.3 mm.

Characterization – Medium-sized, subrounded-subtrigonate relatively flat to semiconvex, high and thin-shelled Didacna . Beak clearly defined but low. Posterodorsal margin steep, broad, well delimited. Semidiameter located on posterior ridge that is well developed and subrounded. Only few of the specimens develop two elevated ribs that form the posterior ridge. Posterior margin subangular to angular. Individuals show 22–28 posterior ribs that are thin and flat and about two times as wide as the interspaces. Juveniles have a high subtrigonate outline with a rounded lower margin and a straight acute posterior ridge resembling the outline of Parvicardium species. The hinge plate is narrow, cardinal tooth well developed.

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.