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Meiourogonyaulax spongiosa
Meiourogonyaulax spongiosa Smelror, 1987, p.230,232, figs.5A–G; text-fig.3.
Originally (and now) Meiourogonyaulax, subsequently Lithodinia. This species is here retained in Meiourogonyaulax following the retention of the genus by Riding and Helby (2001d, p.81,83).
Holotype: Smelror, 1987, fig.5B
Age: Late Callovian
Original description (Smelror, 1987)
Description- Dinoflagellate cysts subspherical in outline. Autophragm is thick, spongy. The ornamentation appears irregular and variouslydeveloped, sometimes as a low reticulum or as more or less fossulate or even foveolate. A gonyaulacoid paratabulation is indicated by parasutural lines ranging from roughened to irregularly punctatoreticulate. The archeopyle appears to be composed of four apical paraplates. and is probably of type (4A).
There are six precingular paraplates. The number of paracingular plates are not known. The parasulcus is expressed as a relatively deep and broad sinerous depression. The parasulcal tabulation pattern is not known. Including the Iu, which rarely is clearly expressed, six postcingular paraplates are present. A posterior intercalary paraplate (X/lpV) is present on the left side of the sulcus. The antapical paraplate is 6-sided and contacts VI (5””) (i.e. the pattern is sexiform). Holotype. - SEM CF-3(1), Figure 5B.
Dimensions. - Length (excluding apical paraplates) 35-52 µm, width 30-49 µm (20 specimens).
Derivation of name. - ‘spongosia’, referring to the spongy autophragm
Type straticum and localitv. - Early Upper Gallovian strata, 168 m a.s.1.. Cape Flora, Northbrook Island. Occurence - Northbrook Island, Cape Flora, sample CF-3 (168m a.s.l.) and CF-U (erratic) Early Upper Callovian.
Remarks. - Meiourogonyaitlax spongiosa sp. nov.seems comparable with Meiourogonyaulax reticulata Dodekova 1975. However, the Callovian specimens from Franz Josef Land differ from the Bulgarian Upper Bathonian specimens described by Dodekova (1975) in lacking well-developed reticulum. Specimens which most probably are conspecific with Meiourogonyaulux spongiosa sp. nov. have also been observed in Early Callovian dinoflagellate cyst assemblages from eastern England by the present author.
Originally (and now) Meiourogonyaulax, subsequently Lithodinia. This species is here retained in Meiourogonyaulax following the retention of the genus by Riding and Helby (2001d, p.81,83).
Holotype: Smelror, 1987, fig.5B
Age: Late Callovian
Original description (Smelror, 1987)
Description- Dinoflagellate cysts subspherical in outline. Autophragm is thick, spongy. The ornamentation appears irregular and variouslydeveloped, sometimes as a low reticulum or as more or less fossulate or even foveolate. A gonyaulacoid paratabulation is indicated by parasutural lines ranging from roughened to irregularly punctatoreticulate. The archeopyle appears to be composed of four apical paraplates. and is probably of type (4A).
There are six precingular paraplates. The number of paracingular plates are not known. The parasulcus is expressed as a relatively deep and broad sinerous depression. The parasulcal tabulation pattern is not known. Including the Iu, which rarely is clearly expressed, six postcingular paraplates are present. A posterior intercalary paraplate (X/lpV) is present on the left side of the sulcus. The antapical paraplate is 6-sided and contacts VI (5””) (i.e. the pattern is sexiform). Holotype. - SEM CF-3(1), Figure 5B.
Dimensions. - Length (excluding apical paraplates) 35-52 µm, width 30-49 µm (20 specimens).
Derivation of name. - ‘spongosia’, referring to the spongy autophragm
Type straticum and localitv. - Early Upper Gallovian strata, 168 m a.s.1.. Cape Flora, Northbrook Island. Occurence - Northbrook Island, Cape Flora, sample CF-3 (168m a.s.l.) and CF-U (erratic) Early Upper Callovian.
Remarks. - Meiourogonyaitlax spongiosa sp. nov.seems comparable with Meiourogonyaulax reticulata Dodekova 1975. However, the Callovian specimens from Franz Josef Land differ from the Bulgarian Upper Bathonian specimens described by Dodekova (1975) in lacking well-developed reticulum. Specimens which most probably are conspecific with Meiourogonyaulux spongiosa sp. nov. have also been observed in Early Callovian dinoflagellate cyst assemblages from eastern England by the present author.