Gymnodinium hyalinum Vozzhennikova, 1967, p.45

Originally Gymnodinium, subsequently Dinogymnium.
Taxonomic senior synonym: Gymnodinium (as Dinogymnium) nelsonense, according to Lentin and Vozzhennikova (1990, p.21).

Holotype: Vozzhennikova, 1967, pl.3, fig.4; Lentin and Vozzhennikova, 1990, pl.2, fig.8; text-fig.7 (lost according to Lentin and Vozzhennikova, 1990.
Locus typicus: W Siberia (Yuzhno-Kolpachevsk area), Russia
Stratum typicum: Senonian
Translation Vozzhennikova, 1967: Lentin and Vozzhennikova, 1990

Original description: Vozzhennikova, 1967, p.45
Theca biconical; epitheca and hypotheca almost equal in size. Transverse furrow narrow, deep, with a slightly wavy or flanged margin. Longitudinal furrow slit-like. In certain forms there are wrinkles running from the transverse furrow towards the poles. The thecal envelope is smooth and transparent.
Size: Holotype, length 67 Ám width 32 Ám; length of epicyst 27 Ám.