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Meiourogonyaulax pertusa
Meiourogonyaulax pertusa (Duxbury, 1977) Below, 1981
Originally Lithodinia, subsequently (and now) Meiourogonyaulax.
Williams et al., 1993, retained this species in Lithodinia Eisenack, 1955.
This combination was not validly published in Fisher and Riley, 1976, since these authors did not fully reference the basionym.
Holotype: Duxbury, 1977, pl.8, fig.5, text-fig.15; Fensome et al., 1991, figs.1-3-p.709; figs.1-3-p.711
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 Ám; Archeopyle formed 65-76x68-86 Ám; 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.
Originally Lithodinia, subsequently (and now) Meiourogonyaulax.
Williams et al., 1993, retained this species in Lithodinia Eisenack, 1955.
This combination was not validly published in Fisher and Riley, 1976, since these authors did not fully reference the basionym.
Holotype: Duxbury, 1977, pl.8, fig.5, text-fig.15; Fensome et al., 1991, figs.1-3-p.709; figs.1-3-p.711
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 Ám; Archeopyle formed 65-76x68-86 Ám; 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.