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Leptodinium aceras
Leptodinium aceras (Eisenack, 1958a, p.391, pl.21, figs.1–2) Sarjeant, 1969, p.12. Emendation: Sarjeant, 1985a, p.57,59, as Cribroperidinium aceras.
Now Cribroperidinium. Originally Gonyaulax, subsequently Leptodinium, thirdly Acanthaulax?, fourthly (and now) Cribroperidinium. See also Gonyaulacysta? (combination not validly published).
Holotype: Eisenack, 1958, pl.21, fig.1; Sarjeant, 1985, pl.4, figs.1-2; Jan du Chêne et al., 1986, pl.2, figs.6-7
Paratype: Eisenack, 1958
Locus typicus: borehole at Marne, Feld Heide, N Germany
Stratum typicum: Aptian
Translation Eisenack, 1958: Sarjeant, 1985
Original diagnosis: Eisenack, 1958, p.391: Gonyaulax aceras
Shell oval, without horns. Epi- and hypotheca almost equal. Transverse furrow spiral, narrow, delimited by solid but low crests. Plate boundaries only partially marked by crests, these and the plate surfaces being set with short, pointed tubercles, so that the tabulation is scarcely discernible.
Emended description: Gitmez and Sarjeant, 1972, p.215
Cyst broadly ovoidal to subsphaerical, without appandages, with tabulation 4", 1a, 6"", 6c, 6""", 1p, 1pv and 1"""". Cingulum helicoid, laevorotatory; sulcus narrow, extending on both epitract and hypotract. Sutures in the form of low membraneous crests. Surface coarsly granular. Archaeopyle rarely developed, formed by the loss of plate 3"".
Now Cribroperidinium. Originally Gonyaulax, subsequently Leptodinium, thirdly Acanthaulax?, fourthly (and now) Cribroperidinium. See also Gonyaulacysta? (combination not validly published).
Holotype: Eisenack, 1958, pl.21, fig.1; Sarjeant, 1985, pl.4, figs.1-2; Jan du Chêne et al., 1986, pl.2, figs.6-7
Paratype: Eisenack, 1958
Locus typicus: borehole at Marne, Feld Heide, N Germany
Stratum typicum: Aptian
Translation Eisenack, 1958: Sarjeant, 1985
Original diagnosis: Eisenack, 1958, p.391: Gonyaulax aceras
Shell oval, without horns. Epi- and hypotheca almost equal. Transverse furrow spiral, narrow, delimited by solid but low crests. Plate boundaries only partially marked by crests, these and the plate surfaces being set with short, pointed tubercles, so that the tabulation is scarcely discernible.
Emended description: Gitmez and Sarjeant, 1972, p.215
Cyst broadly ovoidal to subsphaerical, without appandages, with tabulation 4", 1a, 6"", 6c, 6""", 1p, 1pv and 1"""". Cingulum helicoid, laevorotatory; sulcus narrow, extending on both epitract and hypotract. Sutures in the form of low membraneous crests. Surface coarsly granular. Archaeopyle rarely developed, formed by the loss of plate 3"".