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Palaeocystodinium obesum

Palaeocystodinium obesum Fensome et al., 2009, p.50, pl.8, figs.j–l.

Holotype: Fensome et al., 2009, pl.8, fig.l.
Age: youngest occurrence, Rupelian.

Original description (Fensome, 2009):
Palaeocystodinium obesum sp. nov. (Plate 8, figs j-l)
Holotype: Plate 8, fig. l; from a sidewall core sample at 751.6 m (2466 feet) in Onondaga E-84 well; GSC type collection no. 130270, sample P37515, slide 01, co-ordinates 14.4 × 106.2, England Finder O49/2.; overall length 129 μm, overall width 45 μm, length of endocyst 92 μm. The age determined for the sample from which the holotype was recovered is Rupelian (Early Oligocene).
AGE ON SCOTIAN MARGIN. LAD: late Rupelian (Early Oli gocene).

Description:
A species of Palaeocystodinium with relatively short, but pointed horns, a smooth periphragm and a broad endocyst. Bicavate, with pericoels restricted to polar regions; wall layers appressed laterally.
Dimensions: Overall length 92(111)129 μm, overall width 45(47)48 μm, length of endocyst 63(82)92μm; 3 specimens measured.

Remarks:
This species resembles, and is probably related to, Svalbardella cooksoniae, but has pointed rather than rounded horns and generally lacks indications of tabulation on the pericyst. Van Simaeys et al. (2005) reported 'globally synchronous Arctic dinoflagellate migration events', specifically species of Svalbardella, reflecting a cooling episode at about 27.1 Ma. This event has yet to be found in Scotian Margin wells.
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