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Gonyaulacysta serrata
Gonyaulacysta serrata (Cookson and Eisenack, 1958) Sarjeant, 1969
Now Rhynchodiniopsis. Originally Gonyaulax, subsequently Gonyaulacysta, thirdly Hystrichogonyaulax fourthly (and now) Rhynchodiniopsis.
This combination was not validly published in Sarjeant, 1966, since that author did not fully reference the basionym.
Holotype: Cookson and Eisenack, 1958, pl.3, fig.2; Jan du Chêne et al., 1986, pl.99, figs.3-4
Locus typicus: Omatia, Papua
Stratum typicum: Late Jurassic-Neocomian
Original description: Cookson and Eisenack, 1958, p. 34: Gonyaulax serrata
All the available specimens are flattened and in consequence polygonal in outline. The plates of both epitheca and hypotheca are relatively large and the transverse girdle is helicoid; the longitudinal furrow extends to the antapical plate. The epitheca is terminated by a very short conical process which is covered with spiny projections and the sutures of the plates and margins of the furrow are ornamented with rather broad comb-like ledges, the teeth of which are either rounded, knob-like or occasionally slightly bifurcate. The exact tabulation could not be determined. However, G. serrata is a readily recognizable form.
Dimensions: Type 109x100 Ám. Another specimen 100x94 Ám; spines c. 2.5-6 Ám long.
Affinities:
Cookson and Eisenack, 1958, p. 34: Gonyaulax serrata
Gonyaulax serrata seems to be closely related to G. cladophora Defl. from thr French Oxfordian. However, it differs from that species in the simpler form and more even length of the spines ornamenting the shell, and in the form of the apical prominence. According to the original diagnosis, G. cladophora always has a distinct tubular apical horn. In G. serrata, on the other hand, only a short blunt apical prominence surmounted by a few short spines is developed.
Now Rhynchodiniopsis. Originally Gonyaulax, subsequently Gonyaulacysta, thirdly Hystrichogonyaulax fourthly (and now) Rhynchodiniopsis.
This combination was not validly published in Sarjeant, 1966, since that author did not fully reference the basionym.
Holotype: Cookson and Eisenack, 1958, pl.3, fig.2; Jan du Chêne et al., 1986, pl.99, figs.3-4
Locus typicus: Omatia, Papua
Stratum typicum: Late Jurassic-Neocomian
Original description: Cookson and Eisenack, 1958, p. 34: Gonyaulax serrata
All the available specimens are flattened and in consequence polygonal in outline. The plates of both epitheca and hypotheca are relatively large and the transverse girdle is helicoid; the longitudinal furrow extends to the antapical plate. The epitheca is terminated by a very short conical process which is covered with spiny projections and the sutures of the plates and margins of the furrow are ornamented with rather broad comb-like ledges, the teeth of which are either rounded, knob-like or occasionally slightly bifurcate. The exact tabulation could not be determined. However, G. serrata is a readily recognizable form.
Dimensions: Type 109x100 Ám. Another specimen 100x94 Ám; spines c. 2.5-6 Ám long.
Affinities:
Cookson and Eisenack, 1958, p. 34: Gonyaulax serrata
Gonyaulax serrata seems to be closely related to G. cladophora Defl. from thr French Oxfordian. However, it differs from that species in the simpler form and more even length of the spines ornamenting the shell, and in the form of the apical prominence. According to the original diagnosis, G. cladophora always has a distinct tubular apical horn. In G. serrata, on the other hand, only a short blunt apical prominence surmounted by a few short spines is developed.