Gonyaulacysta micoceras (Eisenack, 1958a, p.391, pl.21, fig.13) Clarke and Verdier, 1967, p.31. Emendation: Sarjeant, 1985a, p.67, as Rhynchodiniopsis microceras.

Now Rhynchodiniopsis?. Originally Gonyaulax, subsequently Gonyaulacysta, thirdly Rhynchodiniopsis, fourthly (and now) Rhynchodiniopsis?.
This combination was not validly published in Sarjeant, 1966, since that author did not fully reference the basionym.

Holotype: Eisenack, 1958, pl.21, fig.13; Sarjeant, 1985, pl.6, figs.5-6, pl.7, fig.6; text-fig.4; Jan du Chêne et al., 1986, pl.99, figs.5-6
Locus typicus: between 761 and 767 m depth, borehole at Marne, Feld Heide, north Germany
Stratum typicum: Late Aptian
Translation Eisenack, 1958: Sarjeant, 1985

Original diagnosis: Eisenack, 1958, p.319: Gonyaulax microceras
Shell oval to polyhedral with short, solid, pointed apical horn. Epi- and hypotheca almost equal, with narrow, spiral transverse furrow enclosed by low crests. Plate boundaries formed by seams, not by crests. Plates granulate, or tuberculate with minute spines, which at times render prominent the plate boundaries.