original description
(of Adacna protracta Eichwald, 1841) Eichwald, E. 1841. Fauna Caspio-Caucasia, nonnullis observationibus novis illustravit. Petersburg, 1841, v + 290 pp., 40 pls., available online at https://www.biodiversitylibrary.org/page/33163056 [details]
original description
(of Didacna protracta var. submedia Andrusov, 1910) Andrusov, N. (1910). Studien über die Brackwassercardiden. Didacna (Erste Hälfte). <em>Mémoires de l'Académie impériale des sciences de St.-Pétersbourg. VIIIe série. Classe physico-mathématique.</em> 25(8): 1-84, pl. 1-10., available online at https://www.biodiversitylibrary.org/page/36733928
page(s): 71, pl. 8, figs 32, 33 [details]
original description
(of Didacna protracta var. grimmi Andrusov, 1910) Andrusov, N. (1910). Studien über die Brackwassercardiden. Didacna (Erste Hälfte). <em>Mémoires de l'Académie impériale des sciences de St.-Pétersbourg. VIIIe série. Classe physico-mathématique.</em> 25(8): 1-84, pl. 1-10., available online at https://www.biodiversitylibrary.org/page/36733928
page(s): 72, pl. IX, fig. 3-4 [details]
original description
(of Didacna protracta var. media Andrusov, 1910) Andrusov, N. (1910). Studien über die Brackwassercardiden. Didacna (Erste Hälfte). <em>Mémoires de l'Académie impériale des sciences de St.-Pétersbourg. VIIIe série. Classe physico-mathématique.</em> 25(8): 1-84, pl. 1-10., available online at https://www.biodiversitylibrary.org/page/36733928
page(s): 72, pl. VIII, fig. 33; pl. IX, fig. 2 [details]
basis of record
Vinarski, M. V.; Kantor, Yu. I. (2016). Analytical catalogue of fresh and brackish water molluscs of Russia and adjacent countries. A. N. Severtsov Institute of Ecology and Evolution of Russian Academy of Science, Moscow, 544 pp.
page(s): 72 [details] Available for editors [request]
status source
Nevesskaja, L.A. (2007). History of the genus <i>Didacna</i> (Bivalvia: Cardiidae). <em>Paleontological Journal.</em> 41(9): 861-949.
page(s): 937, pl. 22, fig. 11 [details] Available for editors [request]
From editor or global species database
Type locality northern Caspian Region; Lower Khvalynian Subhorizon [the neotype locality] [details]