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Sindridinium torulosum
From Fensome et al., 2019:
Sindridinium torulosum (Davey and Verdier, 1973, p.180,183, pl.1, figs.2,5,8) Nøhr-Hansen et al., 2017, p.384.
Holotype: Davey and Verdier, 1973, pl.1, fig.2.
Originally Canningia, subsequently Batiacasphaera, thirdly Ovoidinium, fourthly (and now) Sindridinium?. Questionable assignment: Nøhr-Hansen et al., 2017, p.384.
Age: late Albian–early Cenomanian.
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Original description: [Davey and Verdier 1973, p. 180]:
Diagnosis:
The cyst is dorso-ventrally flattened, subcircular to ovoidal in outline and without apical or antapical structures. The wall is thin, smooth to lightly granular, and bears a number of low tubercles of circular outline.
They are irregularly aligned along the plate margins and are especially noticeable along the borders of the cingulum; intratabular tubercles are also present. The cingulum, which divides the cyst into an epitract and hypotract of equal size, and sulcus are usually devoid of ornamentation.
An apical archaeopyle is present with the operculum often remaining in place. The former is only slightly angular and precingular sutural breakages are rarely present.
Description:
Since the cyst wall is relatively thin (approximately 1 ll) and the cyst originally of subspherical shape, some distortion is always present. This distortion most usually takes the form of one or two longitudinal folds (pl. 1, fig. 5). The tubercles are low ( under than 1µm in height ) and dislike, being circular in outline and approximately 1µm in diameter. Tubercle alignment in the pre- and postcingular areas is always very noticeable and presumably follows the reflected plate boundaries. However, these boundaries, except in the case of the cingulum, are never completely outlined and this, together with the presence of intratabular tubercles, makes the cyst tabulation difficult to decipher.
Dimensions:
Holotype Paratype Range
Cyst length: 59 µm 52 (56) 61 µm
Cyst length (with archaeopyle): 41 µm 41-58 µm
Cyst width: 51 µm 45 µm 45 (51) 65 µm
Remarks:
C. torulosa sp. nov. is an easily recognisable species and immediately distinguishable from all previous described forms.
Sindridinium torulosum (Davey and Verdier, 1973, p.180,183, pl.1, figs.2,5,8) Nøhr-Hansen et al., 2017, p.384.
Holotype: Davey and Verdier, 1973, pl.1, fig.2.
Originally Canningia, subsequently Batiacasphaera, thirdly Ovoidinium, fourthly (and now) Sindridinium?. Questionable assignment: Nøhr-Hansen et al., 2017, p.384.
Age: late Albian–early Cenomanian.
---------------------------------------------------------------------------------------------------
Original description: [Davey and Verdier 1973, p. 180]:
Diagnosis:
The cyst is dorso-ventrally flattened, subcircular to ovoidal in outline and without apical or antapical structures. The wall is thin, smooth to lightly granular, and bears a number of low tubercles of circular outline.
They are irregularly aligned along the plate margins and are especially noticeable along the borders of the cingulum; intratabular tubercles are also present. The cingulum, which divides the cyst into an epitract and hypotract of equal size, and sulcus are usually devoid of ornamentation.
An apical archaeopyle is present with the operculum often remaining in place. The former is only slightly angular and precingular sutural breakages are rarely present.
Description:
Since the cyst wall is relatively thin (approximately 1 ll) and the cyst originally of subspherical shape, some distortion is always present. This distortion most usually takes the form of one or two longitudinal folds (pl. 1, fig. 5). The tubercles are low ( under than 1µm in height ) and dislike, being circular in outline and approximately 1µm in diameter. Tubercle alignment in the pre- and postcingular areas is always very noticeable and presumably follows the reflected plate boundaries. However, these boundaries, except in the case of the cingulum, are never completely outlined and this, together with the presence of intratabular tubercles, makes the cyst tabulation difficult to decipher.
Dimensions:
Holotype Paratype Range
Cyst length: 59 µm 52 (56) 61 µm
Cyst length (with archaeopyle): 41 µm 41-58 µm
Cyst width: 51 µm 45 µm 45 (51) 65 µm
Remarks:
C. torulosa sp. nov. is an easily recognisable species and immediately distinguishable from all previous described forms.