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Cleistosphaeridium
From Williams et al., 2017:
[Cleistosphaeridium, Davey et al., 1966, p. 166; Emendations: Eaton et al., 2001, p.176.
tax. jr. synonym of Systematophora, according to Islam (1993, p.88) - however, Eaton et al. (2001, p.176) retained Cleistosphaeridium.
tax. jr. synonym of Laticavodinium Wilson and Sarjeant in Sarjeant, 1984, according to Stover and Williams, 1987, however, Laticavodinium is now considered to be a taxonomic junior synonym of Impletosphaeridium.
Type species: Cleistosphaeridium diversispinosum, Davey et al., 1966 (pl.10, fig.7)]
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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; Emendations: Eaton et al., 2001, p.176.
tax. jr. synonym of Systematophora, according to Islam (1993, p.88) - however, Eaton et al. (2001, p.176) retained Cleistosphaeridium.
tax. jr. synonym of Laticavodinium Wilson and Sarjeant in Sarjeant, 1984, according to Stover and Williams, 1987, however, Laticavodinium is now considered to be a taxonomic junior synonym of Impletosphaeridium.
Type species: Cleistosphaeridium diversispinosum, Davey et al., 1966 (pl.10, fig.7)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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.