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Acanthaulax acanthosphaera
From Fensome et al., 2019:
Acanthaulax acanthosphaera (Sarjeant, 1961a, p.94-95, pl.13, fig.14; text-fig.4) Sarjeant, 1968, p.227.
Emendation: Sarjeant, 1976c, p.12, as Meiourogonyaulax? acanthosphaera.
Holotype: Sarjeant, 1961a, pl.13, fig.14; text-fig.4; Sarjeant, 1976c, pl.5, figs.2,4.
NOW Meiourogonyaulax?.
Originally Gonyaulax (Appendix B), subsequently Acanthogonyaulax (combination not validly published), thirdly Acanthaulax, fourthly Meiourogonyaulax, fifthly (and now) Meiourogonyaulax?, sixthly Lithodinia, seventhly Lithodinia?.
Age: early Oxfordian.
Locus typicus: Scarborough Castle Cliff; England
Stratum typicum: Lowest Oxford Clay, Oxfordian
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Original description as Gonyaulax acantosphaera: [Sarjeant, 1961, p.94]:
Diagnosis:
A Species of fossil Gonyaulax having a globular theca with the tabulation ?3', 1a, 6", ?6''', ?2pv, 1'''' and without an apical horn. A dense cover of extremely short, blunt, stubble-like spines covers the entire theca, being somewhat reduced on the transverse and longitudinal furrows. Sutures between plates not raised, but ornamented with rows of short spinelets, some bifurcating, longer than those of the general spine cover.
Description:
Theca yellowish in colour. Tabulation not easy to determine since sutures are not raised and their longer spines readily escape notice against the dense background of shorter spines Apparently three apical plates: however, plate 1' of type gives suggestion of possible subdivision into two. One anterior intercalary plate and six pre-equatorial plates, with plate 1" reduced. Transverse furrow extends around theca in laevo-rotatory spiral such that its two ends differ in antero-posterior position by the furrow's width. Longitudinal furrow broad: small posterior ventral plate present, corresponding to its hypothecal extension and adjacent to the more posterior of the two ends of the transverse furrow. A second posterior ventral plate, somewhat larger in size, appears to be present between this and the polygonal antapical plate. Six postequatorial plates present. Holotype somewhat damaged; tabulation of the dorsal surface therefore based on the Paratype.
Dimensions:
Holotype: Length 65 µm, breadth 65 µm, transverse furrow c. 5 µm in width. Spines elsewhere c. 0,3 µm in length.
Acanthaulax acanthosphaera (Sarjeant, 1961a, p.94-95, pl.13, fig.14; text-fig.4) Sarjeant, 1968, p.227.
Emendation: Sarjeant, 1976c, p.12, as Meiourogonyaulax? acanthosphaera.
Holotype: Sarjeant, 1961a, pl.13, fig.14; text-fig.4; Sarjeant, 1976c, pl.5, figs.2,4.
NOW Meiourogonyaulax?.
Originally Gonyaulax (Appendix B), subsequently Acanthogonyaulax (combination not validly published), thirdly Acanthaulax, fourthly Meiourogonyaulax, fifthly (and now) Meiourogonyaulax?, sixthly Lithodinia, seventhly Lithodinia?.
Age: early Oxfordian.
Locus typicus: Scarborough Castle Cliff; England
Stratum typicum: Lowest Oxford Clay, Oxfordian
---------------------------------------------------------------------------------------------------
Original description as Gonyaulax acantosphaera: [Sarjeant, 1961, p.94]:
Diagnosis:
A Species of fossil Gonyaulax having a globular theca with the tabulation ?3', 1a, 6", ?6''', ?2pv, 1'''' and without an apical horn. A dense cover of extremely short, blunt, stubble-like spines covers the entire theca, being somewhat reduced on the transverse and longitudinal furrows. Sutures between plates not raised, but ornamented with rows of short spinelets, some bifurcating, longer than those of the general spine cover.
Description:
Theca yellowish in colour. Tabulation not easy to determine since sutures are not raised and their longer spines readily escape notice against the dense background of shorter spines Apparently three apical plates: however, plate 1' of type gives suggestion of possible subdivision into two. One anterior intercalary plate and six pre-equatorial plates, with plate 1" reduced. Transverse furrow extends around theca in laevo-rotatory spiral such that its two ends differ in antero-posterior position by the furrow's width. Longitudinal furrow broad: small posterior ventral plate present, corresponding to its hypothecal extension and adjacent to the more posterior of the two ends of the transverse furrow. A second posterior ventral plate, somewhat larger in size, appears to be present between this and the polygonal antapical plate. Six postequatorial plates present. Holotype somewhat damaged; tabulation of the dorsal surface therefore based on the Paratype.
Dimensions:
Holotype: Length 65 µm, breadth 65 µm, transverse furrow c. 5 µm in width. Spines elsewhere c. 0,3 µm in length.