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Vesperopsis nebulosa
From Fensome et al., 2019:
Vesperopsis nebulosa Bint, 1986, p.157, pl.6, figs.1–5.
Holotype: Bint, 1986, pl.6, figs.1–2.
Age: late Albian.
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Original description: Bint, 1986, p.157
Intermediate-sized, dorso-ventrally compressed cysts with short apical, two lateral, and two antapical horns. All horns are about equal in size. Apical horn wide-based, conical, and rounded. Lateral horns about equal in size, broadly rounded, and with a short, narrowly rounded postcingular extension. Antapical horns subequal in size and narrowly rounded distally; occasionally one antapical horn, probably the left one, is slightly larger. Acavate, autophragm smooth and extremely thin.
Paratabulation not expressed. Cingulum may be indicated by indentation of the lateral horns; sulcus not indicated. Archeopyle apical, operculum usually in place and adnate, but on rare specimens may be broken away. Archeopyle suture weakly angular or rounded, incomplete, ranging from short lateral nicks between the apical and precingular series to a rarely occuring fully developed state in which only a mid-ventral attachment area remains between the operculum and the cyst body.
Size. Length of complete specimen 70(77)86 µm; width 68(76)84 µm; 15 specimens measured.
Remarks. Being thin-walled and fragile, specimens of V. nebulosa were always badly damaged by SEM mounting procedures and thus were not suitable for photography.
Affinities:
Bint, 1986, p.157: Vesperopsis nebulosa differs from V. mayi in that all horns are broad and about the same size. In V. mayi the apical and left antapical horns are long and narrow, the lateral horns are intermediate in length, and the right antapical horn is very short. Nyktericysta sp. A is superficially similar but differs by having a bilayered cyst which is cornucavate.
Vesperopsis nebulosa Bint, 1986, p.157, pl.6, figs.1–5.
Holotype: Bint, 1986, pl.6, figs.1–2.
Age: late Albian.
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Original description: Bint, 1986, p.157
Intermediate-sized, dorso-ventrally compressed cysts with short apical, two lateral, and two antapical horns. All horns are about equal in size. Apical horn wide-based, conical, and rounded. Lateral horns about equal in size, broadly rounded, and with a short, narrowly rounded postcingular extension. Antapical horns subequal in size and narrowly rounded distally; occasionally one antapical horn, probably the left one, is slightly larger. Acavate, autophragm smooth and extremely thin.
Paratabulation not expressed. Cingulum may be indicated by indentation of the lateral horns; sulcus not indicated. Archeopyle apical, operculum usually in place and adnate, but on rare specimens may be broken away. Archeopyle suture weakly angular or rounded, incomplete, ranging from short lateral nicks between the apical and precingular series to a rarely occuring fully developed state in which only a mid-ventral attachment area remains between the operculum and the cyst body.
Size. Length of complete specimen 70(77)86 µm; width 68(76)84 µm; 15 specimens measured.
Remarks. Being thin-walled and fragile, specimens of V. nebulosa were always badly damaged by SEM mounting procedures and thus were not suitable for photography.
Affinities:
Bint, 1986, p.157: Vesperopsis nebulosa differs from V. mayi in that all horns are broad and about the same size. In V. mayi the apical and left antapical horns are long and narrow, the lateral horns are intermediate in length, and the right antapical horn is very short. Nyktericysta sp. A is superficially similar but differs by having a bilayered cyst which is cornucavate.