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Cerodinium leptodermum
Cerodinium leptodermum, (Vozzhennikova, 1963), Lentin and Williams, 1987
Originally Ceratiopsis (an illegitimate generic name), subsequently Deflandrea, thirdly (and now) Cerodinium.
Holotype: Vozzhennikova, 1963, text-fig.8; Lentin and Vozzhennikova, 1990, pl.4, figs.4-5, text-fig.15
Locus typicus: Western Siberia (Uvat), Russia
Stratum typicum: Palaeocene
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Original description: [Vozzhennikova, 1963, p. 180]: (Translation: Lentin and Vozzhennikova, 1990):
Description:
Cells ovally elongate or ovate with long horns, one apical and two antapical, slightly divergent. Girdle annular, running round the equator or displaced slightly forward. Longitudinal groove on epivalve not developed but on the hypovalve extending to the posterior margin. Membrane slightly yellow, leathery, thin, delicate, smooth. Internal cell cavity occupied by internal body of darker color than membrane.
Dimensions:
Length of cell with processes 126.5-177 µm, width 50.6-60 µm, length of apical horn 34.5-52.9 µm, length of antapical horns 20-32 µm.
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Expanded description:
Lentin and Vozzhennikova, 1990, p.36:
Description:
Cyst elongated peridinioid with one long apical and two long antapical horns; endocyst elongated oval; apically cornucavate, antapical pericoel well developed.
Periphragm thin with delicate longitudinal wrinkles or folds; endophragm smooth or minutely granulose, both wall layers tend to show a dark brown color.
Paratabulation absent except as expressed by the archeopyle and paracingulum.
Archeopyle large standard hexa (iso-deltaform) formed by the loss of the 2a paraplate in both wall layers.
Paracingulum is shallow, indistinct to distinct, bordered by crenulations which are expressions of the folds in the periphragm. The perisulcus is shallow and expressed only as a depression on the hypocyst.
Dimensions:
Holotype, length 126 µm, breadth 51 µm; range, length 126 - 177 µm, breadth 50 - 60 µm.
Originally Ceratiopsis (an illegitimate generic name), subsequently Deflandrea, thirdly (and now) Cerodinium.
Holotype: Vozzhennikova, 1963, text-fig.8; Lentin and Vozzhennikova, 1990, pl.4, figs.4-5, text-fig.15
Locus typicus: Western Siberia (Uvat), Russia
Stratum typicum: Palaeocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Vozzhennikova, 1963, p. 180]: (Translation: Lentin and Vozzhennikova, 1990):
Description:
Cells ovally elongate or ovate with long horns, one apical and two antapical, slightly divergent. Girdle annular, running round the equator or displaced slightly forward. Longitudinal groove on epivalve not developed but on the hypovalve extending to the posterior margin. Membrane slightly yellow, leathery, thin, delicate, smooth. Internal cell cavity occupied by internal body of darker color than membrane.
Dimensions:
Length of cell with processes 126.5-177 µm, width 50.6-60 µm, length of apical horn 34.5-52.9 µm, length of antapical horns 20-32 µm.
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Expanded description:
Lentin and Vozzhennikova, 1990, p.36:
Description:
Cyst elongated peridinioid with one long apical and two long antapical horns; endocyst elongated oval; apically cornucavate, antapical pericoel well developed.
Periphragm thin with delicate longitudinal wrinkles or folds; endophragm smooth or minutely granulose, both wall layers tend to show a dark brown color.
Paratabulation absent except as expressed by the archeopyle and paracingulum.
Archeopyle large standard hexa (iso-deltaform) formed by the loss of the 2a paraplate in both wall layers.
Paracingulum is shallow, indistinct to distinct, bordered by crenulations which are expressions of the folds in the periphragm. The perisulcus is shallow and expressed only as a depression on the hypocyst.
Dimensions:
Holotype, length 126 µm, breadth 51 µm; range, length 126 - 177 µm, breadth 50 - 60 µm.