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Chytroeisphaeridia minor ssp. psilata
Chytroeisphaeridia minor ssp. psilata, (Burger, 1980), Lentin and Williams, 1985
Now Kallosphaeridium? helbyi ssp. psilatum. Originally Canningia? minor var. psilata, subsequently Canningia? minor ssp. psilata, thirdly Chytroeisphaeridia minor ssp. psilata, fourthly (and now) Kallosphaeridium? helbyi ssp. psilatum.
Lentin and Williams, 1981, raised this taxon to the subspecies level.
Holotype: Burger, 1980, pl.25, fig.10
Age: Aptian-Albian
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Original description: [Burger, 1980]
Description:
Cyst spherical to egg-shaped, without apical or antapical horns.
Archaeopyle apical with a circular outline, margin notched, outlining the presence of 6 precingular paraplates.
No other traces of paratabulation are visible.
Cyst wall single-layered, psilate, 0.5-1.5 µm thick.
Dimensions:
Apical diameter (26 dehisced specimens) 32-(50)-65 µm, width (34 specimens) 26-(46)-84 µm.
Remarks:
The specimens from the Surat Basin are consistently psilate, in which respect they vary from Canningia minor itself.
Distribution:
A rare to uncommon species in marine assemblages from the Surat Basin. Norvick (1975) reported similar specimens from the Cenomanian of Bathurst Island as Chytroeisphaeridia sp. aff. C. chytroeides (Sarjeant) Downie, Evitt & Sarjeant, 1963, and ?Chytroeisphaeridia sp. A; however, the genus Chytroeisphaeridia incorporates specimens with a precingular archaeopyle (Davey, pers. comm.).
Now Kallosphaeridium? helbyi ssp. psilatum. Originally Canningia? minor var. psilata, subsequently Canningia? minor ssp. psilata, thirdly Chytroeisphaeridia minor ssp. psilata, fourthly (and now) Kallosphaeridium? helbyi ssp. psilatum.
Lentin and Williams, 1981, raised this taxon to the subspecies level.
Holotype: Burger, 1980, pl.25, fig.10
Age: Aptian-Albian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Burger, 1980]
Description:
Cyst spherical to egg-shaped, without apical or antapical horns.
Archaeopyle apical with a circular outline, margin notched, outlining the presence of 6 precingular paraplates.
No other traces of paratabulation are visible.
Cyst wall single-layered, psilate, 0.5-1.5 µm thick.
Dimensions:
Apical diameter (26 dehisced specimens) 32-(50)-65 µm, width (34 specimens) 26-(46)-84 µm.
Remarks:
The specimens from the Surat Basin are consistently psilate, in which respect they vary from Canningia minor itself.
Distribution:
A rare to uncommon species in marine assemblages from the Surat Basin. Norvick (1975) reported similar specimens from the Cenomanian of Bathurst Island as Chytroeisphaeridia sp. aff. C. chytroeides (Sarjeant) Downie, Evitt & Sarjeant, 1963, and ?Chytroeisphaeridia sp. A; however, the genus Chytroeisphaeridia incorporates specimens with a precingular archaeopyle (Davey, pers. comm.).