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Cyclonephelium cuculliforme

From Fensome et al., 2019:
Cyclonephelium cuculliforme (Davies, 1983, p.29, pl.10, figs.1–4; text-fig.26) Århus, 1992, p.312. Holotype: Davies, 1983, pl.10, figs.3–4; Fauconnier and Masure, 2004, pl.69, figs.1–3. Originally Sentusidinium, subsequently Sentusidinium?, thirdly Cyclonephelium. Taxonomic senior synonym: Cleistosphaeridium (now Sentusidinium) separatum, according to Courtinat in Fauconnier and Masure (2004, p.486) — however, Sentusidinium cuculliforme is now considered a taxonomic junior synonym of Vexillocysta colligata. Taxonomic senior synonym: Tenua (now Vexillocysta) colligata, according to Duxbury (2018, p.196). Age: Berriasian–Valanginian.

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Original diagnosis: Davies, 1983, p.29: Sentusidinium cuculliforme
A species of Sentusidinium having a sphaerical to ovoidal shape; dense covering of sturdy spines which are complexely terminated and reduced or lacking along the cingulum. The accessory sutures are weakly developed between the precingular plates.
Tabulation: only 4", 6"" are evident.
Archaeopyle: (4A)a+6Pa, the ventrally attached operculum is often removed.
Size: length - 48(63)81 µm; breadth - 49(63)77 µm (19 specimens)

Original description: Davies, 1983, p.29: Sentusidinium cuculluiforme
the spines (3(7)16Á) are broadly based, tapering to acuminate, foliate, capitate or acicular terminations. The spines are aligned adcingulary with coalescent bases. Other plate boundaries are also suggested by spine alignment but they are obscured by the spine density and inconsistance in alignment. The cingulum is positioned equatorially, dividing the cyst into two equal halves. Rarely, some precingular plates may be dislocated after archaeopyle formation.

Supplemental description: Arhus, 1992, p. 312
Essentially as reported by Davies (1983). SEM examination shows that penitabular processes are sitting on ridges which are not fully interconnected into septae. Intratabular processes situated either on less well developed ridges or having non-coalescent bases. Bifurcation is not observed in intratabular processes.

Affinities:
Davies, 1983, p.29: Sentusidinium cuculliforme
S. echinatum is distinguished from S. cuculliforme by its more regularly spaced, simple spines and the lack of a distinct cingulum. S. pilosum has more widely spaced ornate to capitate spines with no cingulum evident. S. rioultii has similar ornament but more widely spaced, as does S. villerense which has narrower and shorter spines.
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