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Meiourogonyaulax pertusa ssp. pertusa
From Fensome et al., 2019:
Meiourogonyaulax pertusa ssp. pertusa Autonym. Holotype: Duxbury, 1977, pl.8, fig.5; text-fig.15; Fensome et al., 1991, figs.1–3 -- p.709; figs.1–3 -- p.711. Originally (and now) Meiourogonyaulax pertusa subsp. pertusa, subsequently
Lithodinia pertusa subsp. pertusa.
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Locus typicus: Speeton, England
Stratum typicum: Berriasian-Hauterivian
Original description: Duxbury 1977, p. 42: Lithodinia pertusa
Diagnosis: A fairly thick-walled proximate cyst. Test wall perforate with very low sutural crests outlining the tabulation 4', 6'', 7c, 7''', 1p, 1pv, 1''''. Archeopyle apical.
Observed dimensions: Holotype 76x81 µm; Archeopyle formed 65-76x68-86 µm; Specimens measured: 7.
Affinities:
Duxbury, 1977, p. 43
The form which bears the closest resemblance to Lithodinia pertusa is that described as Gonyaulacysta bulloidea in Cookson adn Eisenack, 1960 and later transferred to Meiourogonyaulax in Sarjeant, 1969. However, in their diagnosis of Gonyaulax bulloidea, Cookson and Eisenack refer to the "granular" nature of both plates and crets. The plates and crests of Lithodinia pertusa are distinctly perforate.
Meiourogonyaulax pertusa ssp. pertusa Autonym. Holotype: Duxbury, 1977, pl.8, fig.5; text-fig.15; Fensome et al., 1991, figs.1–3 -- p.709; figs.1–3 -- p.711. Originally (and now) Meiourogonyaulax pertusa subsp. pertusa, subsequently
Lithodinia pertusa subsp. pertusa.
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Locus typicus: Speeton, England
Stratum typicum: Berriasian-Hauterivian
Original description: Duxbury 1977, p. 42: Lithodinia pertusa
Diagnosis: A fairly thick-walled proximate cyst. Test wall perforate with very low sutural crests outlining the tabulation 4', 6'', 7c, 7''', 1p, 1pv, 1''''. Archeopyle apical.
Observed dimensions: Holotype 76x81 µm; Archeopyle formed 65-76x68-86 µm; Specimens measured: 7.
Affinities:
Duxbury, 1977, p. 43
The form which bears the closest resemblance to Lithodinia pertusa is that described as Gonyaulacysta bulloidea in Cookson adn Eisenack, 1960 and later transferred to Meiourogonyaulax in Sarjeant, 1969. However, in their diagnosis of Gonyaulax bulloidea, Cookson and Eisenack refer to the "granular" nature of both plates and crets. The plates and crests of Lithodinia pertusa are distinctly perforate.