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Phanerodinium cassiculum
Phanerodinium cassiculum (Wilson, 1984) Below, 1987
Now Microdinium. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams, 1993 retained the species in Microdinium Cookson and Eisenack, 1960.
Holotype: Wilson, 1984, figs.6-7
Locus typicus: Leamington Stream, North Canterbury, New Zealand, grid reference N33/205249
Stratum typicum: Maastrichtian
Original description: Wilson, 1984, p.552: Microdinium cassiculum
Cyst slightly ovoidal and apparently comprising autophragm only, although some specimens may possess a very thin closely appressed ectophragm; 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 8µm), segmented, and slightly spiralled.
Dimensions: Holotype: overall length (excluding operculum) 50µm, breadth 47µm. Range (20 specimens): length (excluding operculum) 46(50)54µm, breadth 41(47)54 µm.
Affinities:
Wilson, 1984, p.552: Microdinium cassiculum
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.
Now Microdinium. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams, 1993 retained the species in Microdinium Cookson and Eisenack, 1960.
Holotype: Wilson, 1984, figs.6-7
Locus typicus: Leamington Stream, North Canterbury, New Zealand, grid reference N33/205249
Stratum typicum: Maastrichtian
Original description: Wilson, 1984, p.552: Microdinium cassiculum
Cyst slightly ovoidal and apparently comprising autophragm only, although some specimens may possess a very thin closely appressed ectophragm; 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 8µm), segmented, and slightly spiralled.
Dimensions: Holotype: overall length (excluding operculum) 50µm, breadth 47µm. Range (20 specimens): length (excluding operculum) 46(50)54µm, breadth 41(47)54 µm.
Affinities:
Wilson, 1984, p.552: Microdinium cassiculum
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.