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Microdinium cassiculus
Microdinium cassiculum Wilson, 1984
Originally (and now) Microdinium, subsequently Phanerodinium.
Below, 1987, transferred this species to Phanerodinium Deflandre, 1937. Lentin and Williams, 1989, retained it in Microdinium.
Lentin and Williams, 1993, did not follow Marheinecke, 1992, who retained this species in Phanerodinium Deflandre, 1937.
Holotype: Wilson, 1984, figs.6-7
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.
Originally (and now) Microdinium, subsequently Phanerodinium.
Below, 1987, transferred this species to Phanerodinium Deflandre, 1937. Lentin and Williams, 1989, retained it in Microdinium.
Lentin and Williams, 1993, did not follow Marheinecke, 1992, who retained this species in Phanerodinium Deflandre, 1937.
Holotype: Wilson, 1984, figs.6-7
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.