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Microdinium cassiculus
From Fensome et al., 2019:
Microdinium cassiculus Wilson, 1984c, p.552, figs.6–10. Holotype: Wilson, 1984c, figs.6–7; Fensome et al., 1996, figs.4–5 — p.2087. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams (1993, p.424) retained this species in Microdinium. NIA. Age: Maastrichtian.
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Locus typicus: Leamington Stream, North Canterbury, New Zealand
Stratum typicum: Maastrichtian
Original description: Wilson, 1984, p.552
Cyst slightly ovoidal and apparently comprising autophragm only, although some specimens may possess a very thin closely appressed etophragm; hypocyst usually somewhat larger than epicyst. Paratabulation defined by low, solid, somewhat irregular and often discontinuous parasutures; paratabulation formula 4', 6", 6c, 6''', 1p, 1'''', Xs. Surface coarsely and irregularly reticulate (lumen up to 6 µm), reticulation being most evident adjacent to parasutures. Archeopyle fairly broad, type tA; operculum sometimes attached on ventral side. Prominent sulcal area located on midventral surface and up to three small sulcal paraplates may be present. Paracingulum broad (up to 8 Ám), segmented, and slightly spiralled.
Dimensions: Holotype: overall length (excluding operculum) 50 µm, breadth 47 µm. Range (20 specimens): length (excluding operculum) 46(50)54 µm, breadth 41(47)54 µm.
Affinities:
Wilson, 1984, p.552: Microdinium cassiculum is a distinctive species and differs from M. reticulatum Vozzhennikova in having much less prominent and more irregular parasutures, a more irregular reticulation pattern, and in being somewhat larger.
Microdinium cassiculus Wilson, 1984c, p.552, figs.6–10. Holotype: Wilson, 1984c, figs.6–7; Fensome et al., 1996, figs.4–5 — p.2087. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams (1993, p.424) retained this species in Microdinium. NIA. Age: Maastrichtian.
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Locus typicus: Leamington Stream, North Canterbury, New Zealand
Stratum typicum: Maastrichtian
Original description: Wilson, 1984, p.552
Cyst slightly ovoidal and apparently comprising autophragm only, although some specimens may possess a very thin closely appressed etophragm; hypocyst usually somewhat larger than epicyst. Paratabulation defined by low, solid, somewhat irregular and often discontinuous parasutures; paratabulation formula 4', 6", 6c, 6''', 1p, 1'''', Xs. Surface coarsely and irregularly reticulate (lumen up to 6 µm), reticulation being most evident adjacent to parasutures. Archeopyle fairly broad, type tA; operculum sometimes attached on ventral side. Prominent sulcal area located on midventral surface and up to three small sulcal paraplates may be present. Paracingulum broad (up to 8 Ám), segmented, and slightly spiralled.
Dimensions: Holotype: overall length (excluding operculum) 50 µm, breadth 47 µm. Range (20 specimens): length (excluding operculum) 46(50)54 µm, breadth 41(47)54 µm.
Affinities:
Wilson, 1984, p.552: Microdinium cassiculum is a distinctive species and differs from M. reticulatum Vozzhennikova in having much less prominent and more irregular parasutures, a more irregular reticulation pattern, and in being somewhat larger.