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Chytroeisphaeridia variabilis
Chyrtoisphaeridia? variabilis, Pocock, 1972
Now Endoscrinium?. Originally Chytroeisphaeridia, subsequently Chytroeisphaeridia?, thirdly Gonyaulacysta, fourthly (and now) Endoscrinium?.
Lentin and Williams, 1977, questionably retained this species in Chytroeisphaeridia.
Holotype: Pocock, 1972, pl.23, fig.15; Jansonius, 1986, pl.3, figs.15-17; text-fig.8; Jan du Chêne et al., 1986, pl.39, figs.5-7
Locus typicus: Tidewater Eastend Crown, W Canada
Stratum typicum: Late Bajocian
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Original description: [Pocock, 1972, p.100]:
Description:
Vesicle ovoid; sometimes differentiated into two portions, an epitheca with a, more or less pointed, solid apex and a hypotheca with a somewhat blunted antapex (Figs. 1-2);
wall about 0.5 µm thick; transparent; ornamented with scattered, low, rounded granules spaced 1.0-3.0 µm apart; vesicle plated; plating too faint to determine tabulation;
epitheca rounded; apex frequently marked by a short, wide horn up to 6.5 µm long with a basal diameter of about 10.0 µm; horn solid; penetrated by an apical pore;
simple precingular archeopyle developed which may be closed with a shield-shaped operculum; helicoidal equatorial girdle present; frequently well developed; hypotheca smoothly rounded (pl.2, fig.1) or asymmetrically blunted at the antapex (pl.2, fig.2); antapical horns not developed; punctate yellow-green bodies present, fused to the inside of the vesicle wall; folds characteristically developed parallel to the sides of the grain which may give the grain the appearance of enclosing a spherical cyst;
colourless to pale yellow;
Dimensions:
size range 60.0 (68.1) 81.0 x 45.0 (53.7) 57.0 Ám.
Affinities:
A very variable species although the size range is reasonably narrow. In appearance the grains vary from typical "peridinoid" form with faint, but distinctly visible, plating to rounded ovoid granulose cysts.The archeopyle is present on all specimens although when the operculum is preserved it is not always obvious. All grains carry punctate yellow-green bodies.
Now Endoscrinium?. Originally Chytroeisphaeridia, subsequently Chytroeisphaeridia?, thirdly Gonyaulacysta, fourthly (and now) Endoscrinium?.
Lentin and Williams, 1977, questionably retained this species in Chytroeisphaeridia.
Holotype: Pocock, 1972, pl.23, fig.15; Jansonius, 1986, pl.3, figs.15-17; text-fig.8; Jan du Chêne et al., 1986, pl.39, figs.5-7
Locus typicus: Tidewater Eastend Crown, W Canada
Stratum typicum: Late Bajocian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Pocock, 1972, p.100]:
Description:
Vesicle ovoid; sometimes differentiated into two portions, an epitheca with a, more or less pointed, solid apex and a hypotheca with a somewhat blunted antapex (Figs. 1-2);
wall about 0.5 µm thick; transparent; ornamented with scattered, low, rounded granules spaced 1.0-3.0 µm apart; vesicle plated; plating too faint to determine tabulation;
epitheca rounded; apex frequently marked by a short, wide horn up to 6.5 µm long with a basal diameter of about 10.0 µm; horn solid; penetrated by an apical pore;
simple precingular archeopyle developed which may be closed with a shield-shaped operculum; helicoidal equatorial girdle present; frequently well developed; hypotheca smoothly rounded (pl.2, fig.1) or asymmetrically blunted at the antapex (pl.2, fig.2); antapical horns not developed; punctate yellow-green bodies present, fused to the inside of the vesicle wall; folds characteristically developed parallel to the sides of the grain which may give the grain the appearance of enclosing a spherical cyst;
colourless to pale yellow;
Dimensions:
size range 60.0 (68.1) 81.0 x 45.0 (53.7) 57.0 Ám.
Affinities:
A very variable species although the size range is reasonably narrow. In appearance the grains vary from typical "peridinoid" form with faint, but distinctly visible, plating to rounded ovoid granulose cysts.The archeopyle is present on all specimens although when the operculum is preserved it is not always obvious. All grains carry punctate yellow-green bodies.