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Ovoidinium verrucosum ssp. ostium
From Fensome et al., 2019:
Ovoidinium verrucosum ssp. ostium (Davey, 1970, p.353, pl.4, figs.5–6; text-fig.1B) Lentin and Williams, 1975, p.2153. Holotype: Davey, 1970, pl.4, fig.5. Originally Ovoidinium ostium, subsequently Ovoidinium verrucosum var. ostium, thirdly (and now) Ovoidinium verrucosum subsp. ostium, fourthly Ascodinium verrucosum subsp. ostium. Lentin and Williams (1989, p.270) retained this taxon as Ovoidinium verrucosum subsp. ostium. Age: Albian–early Cenomanian.
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Locus typicus: Saskatchewan, Canada
Stratum typicum: Albian-Early Cenomanian
Original diagnosis: Davey, 1970, p. 353: Ovoidinium ostium
Inner body subspherical, lightly but densely granular, with moderately thick wall. Periphragm slightly granular, sometimes bearing tubercles. Apical pericoel small, with poorly. developed horn; posterior pericoel asymmetrical, possessing sub-rectangular opening on ventral surface. Cingulum and sulcus moderately well defined. Apical region generally lost in archaeopyle formation.
Dimensions: Holotype: overall length 59 µm, length of inner body 39 µm, width of inner body 40 µm. Paratype: length (operculum missing) 50 µm, length of inner body 35 µm, width of inner body 45 µm. Range: length (operculum missing) 37 (46 2) 63 µm, length of inner body 28 (34.4) 45 µm, width of inner body 37 (39.1) 54 µm.
Original description: Davey, 1970, p. 353: Ovoidinium ostium
The inner body wall (1-1.5 µm thick) is surrounded by an outer membrane (approximately 0.5 µm thick), the two being in contact only in the cingular region. A characteristic sub-rectangular shaped opening is always developed on the ventral surface of the posterior pericoel membrane (text-fig. IB). The opening lies towards the posterior end of the sulcus and is typically closed by an operculum. The operculum of the apical archaeopyle is usually detached and the archaeopye margin is only sightly angular.
Ovoidinium verrucosum ssp. ostium (Davey, 1970, p.353, pl.4, figs.5–6; text-fig.1B) Lentin and Williams, 1975, p.2153. Holotype: Davey, 1970, pl.4, fig.5. Originally Ovoidinium ostium, subsequently Ovoidinium verrucosum var. ostium, thirdly (and now) Ovoidinium verrucosum subsp. ostium, fourthly Ascodinium verrucosum subsp. ostium. Lentin and Williams (1989, p.270) retained this taxon as Ovoidinium verrucosum subsp. ostium. Age: Albian–early Cenomanian.
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Locus typicus: Saskatchewan, Canada
Stratum typicum: Albian-Early Cenomanian
Original diagnosis: Davey, 1970, p. 353: Ovoidinium ostium
Inner body subspherical, lightly but densely granular, with moderately thick wall. Periphragm slightly granular, sometimes bearing tubercles. Apical pericoel small, with poorly. developed horn; posterior pericoel asymmetrical, possessing sub-rectangular opening on ventral surface. Cingulum and sulcus moderately well defined. Apical region generally lost in archaeopyle formation.
Dimensions: Holotype: overall length 59 µm, length of inner body 39 µm, width of inner body 40 µm. Paratype: length (operculum missing) 50 µm, length of inner body 35 µm, width of inner body 45 µm. Range: length (operculum missing) 37 (46 2) 63 µm, length of inner body 28 (34.4) 45 µm, width of inner body 37 (39.1) 54 µm.
Original description: Davey, 1970, p. 353: Ovoidinium ostium
The inner body wall (1-1.5 µm thick) is surrounded by an outer membrane (approximately 0.5 µm thick), the two being in contact only in the cingular region. A characteristic sub-rectangular shaped opening is always developed on the ventral surface of the posterior pericoel membrane (text-fig. IB). The opening lies towards the posterior end of the sulcus and is typically closed by an operculum. The operculum of the apical archaeopyle is usually detached and the archaeopye margin is only sightly angular.