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Ovoidinium ostium
Ovoidinium ostium Davey, 1970
Now Ovoidinium verrucosum ssp. ostium. Originally Ovoidinium ostium, subsequently Ovoidinium verrucosum var. ostium, thirdly (and now) Ovoidinium verrucosum ssp. ostium, fourthly Ascodinium verrucosum ssp. ostium.
Lentin and Williams, 1985, transferred this taxon to Ascodinium Cookson and Eisenack, 1960, as Ascodinium verrucosum ssp. ostium. Lentin and Williams, 1989, retained it in Ovoidinium as Ovoidinium verrucosum ssp. ostium (Davey, 1970) Lentin and Williams, 1975.
Holotype: Davey, 1970, pl.4, fig.5
Locus typicus: Saskatchewan, Canada
Stratum typicum: Albian-Early Cenomanian
Original diagnosis: Davey, 1970, p. 353
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 Ám, length of inner body 39 Ám, width of inner body 40 Ám. Paratype: length (operculum missing) 50 Ám, length of inner body 35 Ám, width of inner body 45 Ám. Range: length (operculum missing) 37 (46 2) 63 Ám, length of inner body 28 (34.4) 45 Ám, width of inner body 37 (39.1) 54 Ám.
Original description: Davey, 1970, p. 353
The inner body wall (1-1.5 Ám thick) is surrounded by an outer membrane (approximately 0.5 Ám 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.
Now Ovoidinium verrucosum ssp. ostium. Originally Ovoidinium ostium, subsequently Ovoidinium verrucosum var. ostium, thirdly (and now) Ovoidinium verrucosum ssp. ostium, fourthly Ascodinium verrucosum ssp. ostium.
Lentin and Williams, 1985, transferred this taxon to Ascodinium Cookson and Eisenack, 1960, as Ascodinium verrucosum ssp. ostium. Lentin and Williams, 1989, retained it in Ovoidinium as Ovoidinium verrucosum ssp. ostium (Davey, 1970) Lentin and Williams, 1975.
Holotype: Davey, 1970, pl.4, fig.5
Locus typicus: Saskatchewan, Canada
Stratum typicum: Albian-Early Cenomanian
Original diagnosis: Davey, 1970, p. 353
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 Ám, length of inner body 39 Ám, width of inner body 40 Ám. Paratype: length (operculum missing) 50 Ám, length of inner body 35 Ám, width of inner body 45 Ám. Range: length (operculum missing) 37 (46 2) 63 Ám, length of inner body 28 (34.4) 45 Ám, width of inner body 37 (39.1) 54 Ám.
Original description: Davey, 1970, p. 353
The inner body wall (1-1.5 Ám thick) is surrounded by an outer membrane (approximately 0.5 Ám 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.