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Ynezidinium waipawaense
Ynezidinium waipawaense, Wilson, 1988, p.24; Lucas-Clark and Helenes, 2000, p.120.
Originally Impagidinium, subsequently (and now) Ynezidinium.
Holotype: Wilson, 1988, pl.14, figs.1a–c; Fensome et al., 1996, figs.1–3 — p.2439.
Age: early-middle Eocene.
Original description: Wilson, 1988 (as Impagidinium waipawaense):
Description:
Cyst subspherical, of intermediate size; autophragm characterised by perforate parasutural septa and smooth intratabular areas. Septa fairly prominent (height up to 4 µm) perforate (perforations 1-3 µm) and generally smooth crested; base of septa relatively broad (up to 3 µm) and may be bordered by narrow perforate zone. Horn short (length 6 µm) broad based (breadth up to 10 µm), somewhat perforate, with an irregular blunt apex.
Paratabulation well defined by septa, gonyaulacacean, formula 4", 6"", 6c, 1p, 1"""", 2-3s.
Archeopyle relatively small (length 14 µm, breadth 17 µm on holotype) Type P; operculum free.
Paracingulum indicated by parallel, transverse ridges (breadth up to 8 µm) and usually comprises 6 paraplates.
Parasulcus extends to epicyst and is somewhat broader on hypocyst; up to three small sulcal paraplates present.
Dimensions:
Holotype: overall length 68 µm, breadth 61 µm, length of horn 10 µm.
Range: length (including horn) 56 (68) 83 µm, breadth 49 (60) 78 µm, horn 6 µm (n= 10).
Affinities:
Wilson, 1988, p. 24: Impagidinium waipawaense differs from previously described species of Impagidinium chiefly in the nature of the parasutural septa which are characteristically perforate.
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Originally Impagidinium, subsequently (and now) Ynezidinium.
Holotype: Wilson, 1988, pl.14, figs.1a–c; Fensome et al., 1996, figs.1–3 — p.2439.
Age: early-middle Eocene.
Original description: Wilson, 1988 (as Impagidinium waipawaense):
Description:
Cyst subspherical, of intermediate size; autophragm characterised by perforate parasutural septa and smooth intratabular areas. Septa fairly prominent (height up to 4 µm) perforate (perforations 1-3 µm) and generally smooth crested; base of septa relatively broad (up to 3 µm) and may be bordered by narrow perforate zone. Horn short (length 6 µm) broad based (breadth up to 10 µm), somewhat perforate, with an irregular blunt apex.
Paratabulation well defined by septa, gonyaulacacean, formula 4", 6"", 6c, 1p, 1"""", 2-3s.
Archeopyle relatively small (length 14 µm, breadth 17 µm on holotype) Type P; operculum free.
Paracingulum indicated by parallel, transverse ridges (breadth up to 8 µm) and usually comprises 6 paraplates.
Parasulcus extends to epicyst and is somewhat broader on hypocyst; up to three small sulcal paraplates present.
Dimensions:
Holotype: overall length 68 µm, breadth 61 µm, length of horn 10 µm.
Range: length (including horn) 56 (68) 83 µm, breadth 49 (60) 78 µm, horn 6 µm (n= 10).
Affinities:
Wilson, 1988, p. 24: Impagidinium waipawaense differs from previously described species of Impagidinium chiefly in the nature of the parasutural septa which are characteristically perforate.
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