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Isabelidinium cretaceum ssp. oviforme
Isabelidinium cretaceum ssp. oviforme Mao Shaozhi and Mohr, 1992
Now Manumiella? cretacea ssp. oviformis. Originally Isabelidinium cretaceum ssp. oviforme, subsequently (and now) Manumiella? cretacea ssp. oviformis.
Holotype: Mao Shaozhi and Mohr, 1992, pl.1, fig.7
Locus typicus: ODP Hole 748c, Banzare Bank, S Indian Ocean
Stratum typicum: Late Campanian
Original description: Mao Shaozhi and Mohr, 1992, p. 320
Cyst circumcavate, ovoid. Apex rounded or slightly projecting; antapex broadly tapered, some slightly concave. The apex is always wider and more round than the antapex. Endocyst subspherical, dorsal side more convex than ventral side. The width of the lateral pericoel is commonly narrower than one-tenth of the total width of the cyst. Wall two layered; periphragm smooth or with verrucae on both apical and antapical areas, and endophragm smooth. Parasulcus, where present, is limited to the hypocyst. Archeopyle intercalary, standard hexastyle, iso-deltaform or rounded at each corner; operculum usually free, rarely attached.
Size. Length of cysts, 90.5 to 112 (holotype 97.2) µm; width of cysts, 80 to 100.5 (holotype 80.2) µm; 20 specimens measured.
Affinities: Mao Shaozhi and Mohr, 1992, p. 320
The subspecies differs from 1. cretaceum gravidum because it has a circumcavate cyst and ovoid shape with the apex always wider and more rounded than the antapex. I. cretaceum cretaceum, according to the holotype (Cookson, 1956, pl. 1, fig. 1), is typically bicavate with a slightly concave antapex.
Now Manumiella? cretacea ssp. oviformis. Originally Isabelidinium cretaceum ssp. oviforme, subsequently (and now) Manumiella? cretacea ssp. oviformis.
Holotype: Mao Shaozhi and Mohr, 1992, pl.1, fig.7
Locus typicus: ODP Hole 748c, Banzare Bank, S Indian Ocean
Stratum typicum: Late Campanian
Original description: Mao Shaozhi and Mohr, 1992, p. 320
Cyst circumcavate, ovoid. Apex rounded or slightly projecting; antapex broadly tapered, some slightly concave. The apex is always wider and more round than the antapex. Endocyst subspherical, dorsal side more convex than ventral side. The width of the lateral pericoel is commonly narrower than one-tenth of the total width of the cyst. Wall two layered; periphragm smooth or with verrucae on both apical and antapical areas, and endophragm smooth. Parasulcus, where present, is limited to the hypocyst. Archeopyle intercalary, standard hexastyle, iso-deltaform or rounded at each corner; operculum usually free, rarely attached.
Size. Length of cysts, 90.5 to 112 (holotype 97.2) µm; width of cysts, 80 to 100.5 (holotype 80.2) µm; 20 specimens measured.
Affinities: Mao Shaozhi and Mohr, 1992, p. 320
The subspecies differs from 1. cretaceum gravidum because it has a circumcavate cyst and ovoid shape with the apex always wider and more rounded than the antapex. I. cretaceum cretaceum, according to the holotype (Cookson, 1956, pl. 1, fig. 1), is typically bicavate with a slightly concave antapex.