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Sentusidinium filiatum

Sentusidinium filiatum Davies 1983

Now Pilosidinium. Originally Sentusidinium, subsequently (and now) Pilosidinium.
Holotype: Davies 1983, pl.10, fig.8
Locus typicus: East Cornwall Island, District of Franklin, Northwest Territories, Canada.
Stratum typicum: Late Oxfordian-Valanginian

Original diagnosis: Davies, 1983, p. 29
A species of Sentusidinium having a spherical to ovoidal shape covered with densely spaced, thread-like spines with no trace of a cingulum or sulcus.
Tabulation: No tabulation except for archeopyle sutures, 4", 6". Archeopyle: (4A) often hinged ventrally with accessory sutures between the precingular plates occasionally developed.
Size - length - 52(61)70 µm; breadth - 35(56)65 µm.

Original description: Davies, 1983, p. 29
The dense, fine spines vary in length (2.5-7.5 µm), terminate simply and acutely and cover the cyst in a carpet-like fashion. There are no horns but rarely two small antapical bulges are evident. The cingulum and sulcus are not clearly defined but the presence of a distinct omphalos in the midventral region is frequent. Whole specimens occur frequently and appear as a densely spinate sphere.

Affinities:
Davies, 1983, p. 30: S. echinatum has shorter and more widely spaced spinate ornament. S. varispinosum has longer, wider and hollow spines. S. cuculliformis has longer, more complexly terminating spines with a distinct cingulum and sulcus.
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