Didacna bacuana Eberzin † (basis of record)
Didacna bogatschevi Pravoslavlev, 1939 † accepted as Didacna subcrassa subcrassa Pravoslavlev, 1939 † (basis of record)
Didacna carditoides Andrusov, 1910 † (additional source)
Didacna catilloides Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna catilloides var. obtusa Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna catillus devexa G. I. Popov, 1983 † accepted as Didacna miussica G. I. Popov, 1983 † (additional source)
Didacna catillus grimmi Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (basis of record)
Didacna catillus volgensis Svitoch, 1967 † (basis of record)
Didacna colossea Asadullaev, 1965 † accepted as Didacna pravoslavlevi pravoslavlevi Fedorov, 1948 † (basis of record)
Didacna cristata Bogachev, 1932 † (basis of record)
Didacna eichwaldi (Krynicki, 1837) (taxonomy source)
Didacna golubyatnikovi Yanina & Svitoch, 1987 † (basis of record)
Didacna grimmi Pravoslavlev, 1939 † (additional source)
Didacna grimmi var. cuneata Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna grimmi var. subquadrata Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna incrassa Pravoslavlev, 1939 † accepted as Didacna subcrassa subcrassa Pravoslavlev, 1939 † (basis of record)
Didacna karabugasica Bogachev † (basis of record)
Didacna naviculata Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna obliquetrigona Pravoslavlev, 1939 † (additional source)
Didacna obliquetrigona var. triquerta Pravoslavlev, 1939 † (source of synonymy)
Didacna ostroumovi Pravoslavlev, 1939 † accepted as Didacna subrudis Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (additional source)
Didacna ovalis Yanina & Svitoch, 1987 † (basis of record)
Didacna paleotrigonoides Fedorov, 1953 † accepted as Didacna praetrigonoides paleotrigonoides Fedorov, 1953 † (additional source)
Didacna pallasi Pravoslavlev, 1939 † accepted as Didacna subpyramidata Pravoslavlev, 1939 † (basis of record)
Didacna pontocaspia (Pavlov, 1925) † (additional source)
Didacna postcarditoides Nalivkin & Anisimov, 1914 † accepted as Didacna nalivkini Vassoevich, 1930 † (basis of record)
Didacna praetrigonoides inderana Svitoch, 1967 † accepted as Didacna praetrigonoides praetrigonoides Nalivkin & Anisimov, 1914 † (basis of record)
Didacna prona Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna pseudocrassa (Pavlov, 1925) † (additional source)
Didacna roseni var. gibbosa Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna rudis var. varia Nalivkin, 1915 † accepted as Didacna rudis Nalivkin, 1915 † (additional source)
Didacna schuraosenica Svitoch & Chernova, 1978 † (basis of record)
Didacna subovalis Pravoslavlev, 1939 † accepted as Didacna vulgaris Andrusov, 1910 † (basis of record)
Didacna subpallasi Pravoslavlev, 1939 † accepted as Didacna subcrassa subcrassa Pravoslavlev, 1939 † (basis of record)
Didacna subrudis Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna subrudis var. pyramidalis Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna subrudis var. trapezoides Pravoslavlev, 1939 † accepted as Didacna grimmi Pravoslavlev, 1939 † (source of synonymy)
Didacna trigonoides chasarica Svitoch, 1967 † (basis of record)
Didacna trigonoides chazarica [sic] † accepted as Didacna trigonoides chasarica Svitoch, 1967 † (basis of record)
Didacna trigonoides chvalynica Svitoch, 1967 † accepted as Didacna ebersini Fedorov, 1953 † (source of synonymy)
Didacna zhukovi Fedorov, 1953 † accepted as Didacna delenda Bogachev, 1932 † (basis of record)
Irinia distorta G. I. Popov, 1956 † accepted as Turcmena distorta (G. I. Popov, 1956) † (additional source)
Neodidacnomya A. A. Ali-Zade, 1973 † accepted as Didacnoides Astaf'yeva, 1960 † (source of synonymy)

North Caucasus for Didacna pallasi Pravoslavlev, 1939 † 
Turkmenistan for Didacna pallasi Pravoslavlev, 1939 † 

 Status

 for Didacna carditoides var. kalickii Pravoslavlev, 1939 †

Not discussed in later revisions of the genus (e.g., Svitoch 1967, Yanina 2005, Nevesskaja 2007). Only mentioned as ... [details]

 Status

 for Didacna obliquetrigona var. triquerta Pravoslavlev, 1939 †

Yanina (2005) considered the variety and the parent species obliquetrigona as synonyms of Didacna catillus grimmi ... [details]

 Synonymy

 for Didacna catillus grimmi Pravoslavlev, 1939 †

Svitoch (1967) and Yanina (2005) considered D. subrudis Pravoslavlev, 1939 as a subjective synonym of Didacna ... [details]

 Synonymy

 for Didacna grimmi Pravoslavlev, 1939 †

Svitoch (1967) and Yanina (2005) considered D. subrudis Pravoslavlev, 1939 as a subjective synonym of Didacna ... [details]

 Synonymy

 for Didacna obliquetrigona Pravoslavlev, 1939 †

Considered a synonym of Didacna catillus grimmi Pravoslavlev, 1939 by Yanina (2005). That taxon was, in turn, ... [details]

 Synonymy

 for Didacna subrudis Pravoslavlev, 1939 †

Svitoch (1967) and Yanina (2005) considered D. subrudis Pravoslavlev, 1939 as a subjective synonym of Didacna ... [details]

 Synonymy

 for Didacna trigonoides chvalynica Svitoch, 1967 †

Considered a synonym of Didacna ebersini Fedorov, 1953 by Yanina (2005). Nevesskaja (2007) listed it as a tentative ... [details]