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Circulodinium colliveri
Circulodinium colliveri, (Cookson and Eisenack, 1960), Helby, 1987
Originally Canningia, subsequently (and now) Circulodinium, thirdly Canninginopsis. Fauconnier and Londeix in Fauconnier and Masure (2004, p.113) retained this species in Circulodinium.
Holotype: Cookson and Eisenack, 1960, pl.38, fig.4
Locus typicus: Jarlemai Siltstone, Western Australia
Stratum typicum: Aptian
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Original description as Canningia colliveri: [Cookson and Eisenack, 1960, p. 251]:
Description:
Shell with straight or rounded sides; apical projection not prominent, basal indentation clearly marked; a "girdle" is usually present slightly above the equator. Shell-membrane densely and irregular reticulate, the reticulum low, small-meshed and thick-walled.
Dimensions:
holotype - 107 µm long, 100 µm broad. Paratype 106 µm long, 90 µm broad.
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Supplemental description:
Mehrota and Sarjeant, 1987, p. 154:
Description:
Proximate cyst, cingulotabulate and lenticular, having a broad apical archaeopyle with a strongly zigzag margin. Antapex bilobate; the left lobe may bear a small horn (pl. 8, fig. 4).
Autophragm ornamented with granules that are isodiametric (less than 1 µm in diameter) and arranged in a regular manner. In addition the ornamentation sometimes also includes a few low spines (< 1 µm), distributed sparsely on the autoblast (pl. 8, fig. 4).
Cingulum suggested by flexures occupying the region of maximum cyst width.
Sulcus not developed, though notch is developed.
Originally Canningia, subsequently (and now) Circulodinium, thirdly Canninginopsis. Fauconnier and Londeix in Fauconnier and Masure (2004, p.113) retained this species in Circulodinium.
Holotype: Cookson and Eisenack, 1960, pl.38, fig.4
Locus typicus: Jarlemai Siltstone, Western Australia
Stratum typicum: Aptian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Canningia colliveri: [Cookson and Eisenack, 1960, p. 251]:
Description:
Shell with straight or rounded sides; apical projection not prominent, basal indentation clearly marked; a "girdle" is usually present slightly above the equator. Shell-membrane densely and irregular reticulate, the reticulum low, small-meshed and thick-walled.
Dimensions:
holotype - 107 µm long, 100 µm broad. Paratype 106 µm long, 90 µm broad.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supplemental description:
Mehrota and Sarjeant, 1987, p. 154:
Description:
Proximate cyst, cingulotabulate and lenticular, having a broad apical archaeopyle with a strongly zigzag margin. Antapex bilobate; the left lobe may bear a small horn (pl. 8, fig. 4).
Autophragm ornamented with granules that are isodiametric (less than 1 µm in diameter) and arranged in a regular manner. In addition the ornamentation sometimes also includes a few low spines (< 1 µm), distributed sparsely on the autoblast (pl. 8, fig. 4).
Cingulum suggested by flexures occupying the region of maximum cyst width.
Sulcus not developed, though notch is developed.