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Simplicidinium
From Fensome et al., 2019:
Simplicidinium, Fensome et al., 2016b, p.66.
Type: Eaton, 1976, pl.21, fig.5, as Impletospaeridium insolitum.
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Original description Fensome et al., 2016b:
Type. Eaton 1976, plate 21, fig. 5, as Impletosphaeridium insolitum.
Etymology. The name derives from the Latin simplicis, meaning simplicity, in reference to the relatively simple morphology of the cyst, comprising a spiny ball with an apical archaeopyle.
Diagnosis. Proximochorate to chorate dinoflagellate cysts with a more or less symmetrical spheroidal to ovoidal central body. Spines or processes numerous, isolated and non-tabulate, distally closed, with symmetrical distal terminations. Archaeopyle apical, type 4A1´– 4´, operculum attached or detached.
Remarks. There seems to be considerable confusion currently surrounding the generic assignment of chorate species with non-tabulate spines/processes and a cryptic, or not clearly discernible or consistent archaeopyle. Forms with a consistent apical archaeopyle and at least some asymmetrical processes are assignable to Cleistosphaeridium (Eaton et al. 2001). Islam (1993) proposed Downiesphaeridium, purportedly for forms with an apical archaeopyle and simple non-tabulate processes. The processes of the type of Downiesphaeridium are typical of Lingulodinium, and the archaeopyle in the type of Downiesphaeridium looks precingular; it is thus suggested here that Downiesphaeridium may be a taxonomic junior synonym of Lingulodinium, but at least should not be used beyond the type. Many authors have assigned species that they consider to be chorate dinoflagellates but show no evidence of an archaeopyle to Impletosphaeridium, the type of that genus being suitably cryptic in its archaeopyle type. Similar species deemed not to be dinoflagellates are assignable to the acritarch genus Baltisphaeridium.
Simplicidinium, Fensome et al., 2016b, p.66.
Type: Eaton, 1976, pl.21, fig.5, as Impletospaeridium insolitum.
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Original description Fensome et al., 2016b:
Type. Eaton 1976, plate 21, fig. 5, as Impletosphaeridium insolitum.
Etymology. The name derives from the Latin simplicis, meaning simplicity, in reference to the relatively simple morphology of the cyst, comprising a spiny ball with an apical archaeopyle.
Diagnosis. Proximochorate to chorate dinoflagellate cysts with a more or less symmetrical spheroidal to ovoidal central body. Spines or processes numerous, isolated and non-tabulate, distally closed, with symmetrical distal terminations. Archaeopyle apical, type 4A1´– 4´, operculum attached or detached.
Remarks. There seems to be considerable confusion currently surrounding the generic assignment of chorate species with non-tabulate spines/processes and a cryptic, or not clearly discernible or consistent archaeopyle. Forms with a consistent apical archaeopyle and at least some asymmetrical processes are assignable to Cleistosphaeridium (Eaton et al. 2001). Islam (1993) proposed Downiesphaeridium, purportedly for forms with an apical archaeopyle and simple non-tabulate processes. The processes of the type of Downiesphaeridium are typical of Lingulodinium, and the archaeopyle in the type of Downiesphaeridium looks precingular; it is thus suggested here that Downiesphaeridium may be a taxonomic junior synonym of Lingulodinium, but at least should not be used beyond the type. Many authors have assigned species that they consider to be chorate dinoflagellates but show no evidence of an archaeopyle to Impletosphaeridium, the type of that genus being suitably cryptic in its archaeopyle type. Similar species deemed not to be dinoflagellates are assignable to the acritarch genus Baltisphaeridium.