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Gymnodinium sphaerocephalum
Gymnodinium sphaerocephalum Vozzhennikova, 1967; Emendation: Lentin and Vozzhennikova, 1990, p.25-26, as Alisogymnium sphaerocephalum.
Now Alisogymnium. Originally Gymnodinium, subsequently Dinogymnium, thirdly (and now) Alisogymnium.
Taxonomic junior synonym: Dinogymnium assamicum, according to Jain (1977a, p.133-134) - however, Lentin and Vozzhennikova (1990, p.28) retained Dinogymnium (as Alisogymnium) assamicum.
Holotype: Vozzhennikova, 1967, pl.3, fig.1; Lentin and Vozzhennikova, 1990, pl.2, figs.6,11-12, text-fig.10
Locus typicus: Western Siberia (Yuzhno-Kolpashevsk area)
Stratum typicum: Senonian
Translation Vozzhennikova, 1967: Lentin and Vozzhennikova, 1990
Original description: Vozzhennikova, 1967, p. 48
Theca flask-shaped or resembling a parachute; epitheca hemispherical, hypotheca funnel-shaped with a tubular process which may be either straight or curved and is bluntly truncated at the end. Transverse furrow annulate, deep. Position of longitudinal furrow indistinct although the furrow itself is probably slit-like. Ribs run from the transverse furrow towards the poles of the theca; they extend about half way across the epitheca but do not reach the cupolar apical part, whereas on the hypotheca they extend almost to the antapex.
Now Alisogymnium. Originally Gymnodinium, subsequently Dinogymnium, thirdly (and now) Alisogymnium.
Taxonomic junior synonym: Dinogymnium assamicum, according to Jain (1977a, p.133-134) - however, Lentin and Vozzhennikova (1990, p.28) retained Dinogymnium (as Alisogymnium) assamicum.
Holotype: Vozzhennikova, 1967, pl.3, fig.1; Lentin and Vozzhennikova, 1990, pl.2, figs.6,11-12, text-fig.10
Locus typicus: Western Siberia (Yuzhno-Kolpashevsk area)
Stratum typicum: Senonian
Translation Vozzhennikova, 1967: Lentin and Vozzhennikova, 1990
Original description: Vozzhennikova, 1967, p. 48
Theca flask-shaped or resembling a parachute; epitheca hemispherical, hypotheca funnel-shaped with a tubular process which may be either straight or curved and is bluntly truncated at the end. Transverse furrow annulate, deep. Position of longitudinal furrow indistinct although the furrow itself is probably slit-like. Ribs run from the transverse furrow towards the poles of the theca; they extend about half way across the epitheca but do not reach the cupolar apical part, whereas on the hypotheca they extend almost to the antapex.