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Cassiculosphaeridia tocheri

Cassiculosphaeridia? tocheri, Schioler, 1993

Holotype: Schioler, 1993, pl.4, figs.4,5
Locus typicus: Well M9x, Dan Field, Danish North Sea
Stratum typicum: Late Maastrichtian

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Original description: [Schioler, 1993, p.104, 106]:

Diagnosis:
A large spherical to subspherical autocyst in which the phragm is ornamented with a thick-walled reticulum enclosing large subspherical lumina.

Description:
A spherical to subspherical autocyst. The autophragm is thick-walled and reticulate, enclosing large subspherical lumina which open to the exterior through irregular subcircular holes. The height of the reticulation and the size of the lumina may vary slightly from specimen to specimen but are approximately constant on a specimen. Height of reticulation and diameter of lumina: 6 - 12 µm.
The archaeopyle is apical, type (tA), judged from its size and shape (Pl. 4, fig. 4), but is often absent or difficult to detect.
Paracingulum and parasulcus are absent.
Paratabulation is not indicated apart from inconsistent presence of archaeopyle.

Dimensions (in µm): holotype range
total diameter: 92 78 (89) 96
height of ectophragm: 9 6 (9) 12
Specimens measured. 13

Affinities:
As archaeopyle relationship is somewhat problematic in this species and paratabulation is absent, it is with some hesitation that the new taxon is established in Class Dinophyceae. Alternatively the taxon could be a spore, a pollen grain, or an acritarch; however, in all the Maastrichtian samples examined during the present study, spores and pollen as well as acritarchs are very rare. The occasional presence of features that point to an apical archaeopyle on the new species (see Pl. 4, figs 4,6,9,11), is currently taken as sufficient evidence by the present author for the location of the taxon in Class Dinophyceae. The new species differs from all other species of Cassiculosphaeridia in having a high and thick-walled reticulum.
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