Gonyaulax muderongensis Cookson and Eisenack 1958

Now Cribroperidinium. Originally Gonyaulax, subsequently (and now) Cribroperidinium; see also Gonyaulacysta (combination not validly published).
Tax. sr. synonym of Gonyaulax (as Cribroperidinium) diaphanis Cookson and Eisenack, 1958, according to Backhouse, 1988.

Holotype: Cookson and Eisenack, 1958, pl.3, fig.7
Locus typicus: Muderong Shale, Carnavon Basin, W-Australia
Stratum typicum: Aptian

Original description: Cookson and Eisenack, p. 32
Theca biconical to oval a with rather long, stiff horn that is closed by a "lid" having a short terminal projection; hypotheca and epitheca nearly equal. Girdle narrow, helicoid; longitudinal furrow short, extending somewhat into the epitheca and not reaching the antapex. Plates numerous, slightly granular provided with irregulary distributed short, blunt spiny outgrouths and worm-like surface ridges, sutures thickened. The girdle is bordered on both sides by short regulary arranged peocesses which are terminations of the ridges on the surface of the plates adjoining it. Wall of theca moderately thick sometimes with an outer thin transparent ornament formed by the coalescence of fine processes.
Dimensions: Range 109-147x94-105 Ám. Apical horn 16-25 Ám long.