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Cassiculosphaeridia alta
Cassiculosphaeridia alta, Pearce, 2010, p.64, p.64,66, pl.1, figs.7–9.
Holotype: pl.1, figs.7–9.
Type locality and horizon: Trunch borehole, Norfolk, UK; 455.9–456.0 m, Burnham–Flamborough Chalk (undifferentiated), mid-Sternotaxis plana Zone (mid-upper Turonian).
Age: early Cenomanian–mid Coniacian.
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Original description: [Pearce, 2010, p.64-66]:
Diagnosis:
A species of Cassiculosphaeridia with relatively high, non-tabular crests.
Description:
Small, sub-spherical, proximate dinoflagellate cyst. The wall is single layered and composed of a smooth autophragm that forms crests. The crests are well-developed and relatively high (up to 7 μm, around one-fifth of the diameter of the central body) and form a complete and irregular, typically polygonal reticulum without traces of a paratabulation.
The archaeopyle is apical (Type tA, operculum detached) and formed by the loss of all apical paraplates.
Affinities:
Differs from species of Valensiella Eisenack, 1963b by lacking an ectophragm. Differs from Cassiculosphaeridia reticulata Davey, 1969 (142, pl. 3, fig. 7; pl. 4, fig. 3) as the most similar species by possessing distinctly higher crests that are stronger and consistently developed. Cassiculosphaeridia magna Davey, 1974 (46, pl. 1, figs 3–7) differs by being much larger (diameter 85–105 μm) with a particularly thick autophragm (up to 3 μm).
Holotype: pl.1, figs.7–9.
Type locality and horizon: Trunch borehole, Norfolk, UK; 455.9–456.0 m, Burnham–Flamborough Chalk (undifferentiated), mid-Sternotaxis plana Zone (mid-upper Turonian).
Age: early Cenomanian–mid Coniacian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Pearce, 2010, p.64-66]:
Diagnosis:
A species of Cassiculosphaeridia with relatively high, non-tabular crests.
Description:
Small, sub-spherical, proximate dinoflagellate cyst. The wall is single layered and composed of a smooth autophragm that forms crests. The crests are well-developed and relatively high (up to 7 μm, around one-fifth of the diameter of the central body) and form a complete and irregular, typically polygonal reticulum without traces of a paratabulation.
The archaeopyle is apical (Type tA, operculum detached) and formed by the loss of all apical paraplates.
Affinities:
Differs from species of Valensiella Eisenack, 1963b by lacking an ectophragm. Differs from Cassiculosphaeridia reticulata Davey, 1969 (142, pl. 3, fig. 7; pl. 4, fig. 3) as the most similar species by possessing distinctly higher crests that are stronger and consistently developed. Cassiculosphaeridia magna Davey, 1974 (46, pl. 1, figs 3–7) differs by being much larger (diameter 85–105 μm) with a particularly thick autophragm (up to 3 μm).