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Parvocysta bullula

From Fensome et al., 2019:
Parvocysta bullula Bjaerke, 1980, p.62,64, pl.1, figs.2–6,9; text-fig.3C. Holotype: Bjaerke, 1980, pl.1, figs.4–5; Fensome et al., 1993a, figs.4–5 — p.997. Originally (and now) Parvocysta, subsequently Dodekovia. Lentin and Williams (1989, p.284) retained this species in Parvocysta. NIA. Age: Toarcian.

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Locus typicus: Knorringfjellet, Spitsbergen
Stratum typicum: Toarcian

Original diagnosis: Bjaerke 1980, p.62, 64
Dinoflagellate cysts of the genus Parvocysta with a subcircular to pentagonal outline. Apical area sometimes narrowing into a short, blunt, apical protrusion. Surface ornamented with blunt processes less than 1 µm high. Paracingulum indicated by a shallow equatorial depression.

Size: 22-35 µm long, 20-31 µm wide.

Original description: Bjaerke, 1980, p. 64
Small dinoflagellate cysts with a subspherical to pentagonal outline, apex slightly pointed, antapex broadly rounded to flat.
Cyst wall: single layered, ornamented with blunt processes less than 1 µm high producing a scabrate appearance.
Paratabulation: except for archaeopyle not observed.
Archaeopyle: intercalary, outline hexagonal with posterior and anterior angulations (geniculate), formed by one middorsal paraplate.
Operculum: in place in most specimens and difficult to distinguish.
Paracingulum: indicated by a shallow equatorial depression.
Parasulcus: seen in some specimens as a shallow depression extending towards the antapical area.

Affinities:
Bjaerke 1980, p. 65: Parvocysta bullula differs from Parvocysta contracta, in that the latter has a characteristic equatorial constriction and a more elongated outline.

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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.

Parvocysta bullula Bjaerke, 1980. This species has a subcircular to pentagonal outline. Apical area sometimes narrowing into a short, blunt apical protrusion. Surface ornamented with blunt processes less than 1 µm high. Paracingulum indicated by a shallow equatorial depression. Archeopyle formed from the loss of one anterior intercalary plate. The operculum is in place in most specimens. Size: 22-35 µm long, 20-31 µm wide.
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