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Cleistosphaeridium
From Fensome et al., 2019:
Cleistosphaeridium, Davey et al., 1966, p.166.
Emendation: Eaton et al., 2001, p.176.
Taxonomic senior synonym: Systematophora, according to Islam (1993, p.88) -- however, Eaton et al. (2001, p.176) retained Cleistosphaeridium. Taxonomic junior synonym: Laticavodinium, according to Stover and Williams (1987, p.145) -- however, Laticavodinium is now considered to be a taxonomic junior synonym of Impletosphaeridium.
Type: Davey et al., 1966, pl.10, fig.7, as Cleistosphaeridium diversispinosum.
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Original description: [Davey et al., 1966]:
Description:
Chorate dinoflagellate cysts having spherical to ovoidal central bodies bearing numerous processes, typically closed distally and without
communication to endocoel. Number of processes typically exceeding 50; processes showing no definite alignment, so that the tabulation is not determinable. Archaeopyle apical, with zigzag margin.
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Modified description:
Stover and Evitt, 1978, p. 31:
Synopsis:
Cysts skolochorate, body subspherical, bearing numerous nontabular processes or spines of similar size and shape that are normally closed distally; indications of paratabulation other than archeopyle characteristically lacking; archeopyle apical, Type tA.
Description:
Shape: Body subspherical.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm with numerous nontabular processes or spines of similar size and shape that are normally closed distally; tips acuminate, bifurcate, or branched. Autophragm between processes or spines smooth to faintly ornamented.
Paratabulation: Indicated by archeopyle only.
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag, often difficult to discern; operculum free.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Size: Intermediate to large.
Affinities:
Cleistosphaeridium differs from Polysphaeridium in having processes that are normally closed rather than open distally. Operculodinium, which also has distally closed processes, possesses a precingular rather than an apical archeopyle. Spines or processes on Cleistosphaeridium are normally similar in size and shape.
Cleistosphaeridium, Davey et al., 1966, p.166.
Emendation: Eaton et al., 2001, p.176.
Taxonomic senior synonym: Systematophora, according to Islam (1993, p.88) -- however, Eaton et al. (2001, p.176) retained Cleistosphaeridium. Taxonomic junior synonym: Laticavodinium, according to Stover and Williams (1987, p.145) -- however, Laticavodinium is now considered to be a taxonomic junior synonym of Impletosphaeridium.
Type: Davey et al., 1966, pl.10, fig.7, as Cleistosphaeridium diversispinosum.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey et al., 1966]:
Description:
Chorate dinoflagellate cysts having spherical to ovoidal central bodies bearing numerous processes, typically closed distally and without
communication to endocoel. Number of processes typically exceeding 50; processes showing no definite alignment, so that the tabulation is not determinable. Archaeopyle apical, with zigzag margin.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt, 1978, p. 31:
Synopsis:
Cysts skolochorate, body subspherical, bearing numerous nontabular processes or spines of similar size and shape that are normally closed distally; indications of paratabulation other than archeopyle characteristically lacking; archeopyle apical, Type tA.
Description:
Shape: Body subspherical.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm with numerous nontabular processes or spines of similar size and shape that are normally closed distally; tips acuminate, bifurcate, or branched. Autophragm between processes or spines smooth to faintly ornamented.
Paratabulation: Indicated by archeopyle only.
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag, often difficult to discern; operculum free.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Size: Intermediate to large.
Affinities:
Cleistosphaeridium differs from Polysphaeridium in having processes that are normally closed rather than open distally. Operculodinium, which also has distally closed processes, possesses a precingular rather than an apical archeopyle. Spines or processes on Cleistosphaeridium are normally similar in size and shape.