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Trithyrodinium velatum
From Fensome et al., 2019:
Trithyrodinium? velatum (Conrad, 1941, p.8–9, pl.1, fig.A ex Sarjeant, 1967b, p.256) Riding and Fensome, 2002, p.24.
Holotype: Conrad, 1941, pl.1, fig.A.
Originally Palaeoperidinium (name not validly published), subsequently Scriniodinium?, thirdly Palaeoperidinium? (combination not validly published), fourthly (and now) Trithyrodinium?.
Questionable assignment: Riding and Fensome (2002, p.24). The name Palaeoperidinium velatum was not validly published in Conrad (1941) since the generic name Palaeoperidinium was not validly published until 1967. Williams et al. (1998, p.550) accepted Sarjeant's (1967b) indirect reference to Conrad (1941) as indication of a type (ICN Article 40.3).
Age: Maastrichtian.
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Original description: [Conrad, 1941] (translated from French):
P. velatum, n. sp. - Pl. 1, fig. A.
The shell is as wide as it is long, angular, bordered by large, concave, rough plates, adorned with small, irregular warts, which give the shell a crenellated outline. The apial and antapical regions are somewhat flattened; the former bears a wide, short, cylindrical process, truncated straight at its free end. This chimney gives P. velatum a pronounced Gonyaulax-like appearance.
The transverse groove could only be observed on its dorsal surface, as the specimen unfortunately did not lend itself to observation, through transparency, from the other surface. It is clearly defined and very deep. It is presumed that its offset, if it truly exists, can only be slight.
The tabulation could not be deciphered. We had to content ourselves with noting the rather vague delineation of a few large, median pentagonal plates located on either side of the transverse groove.
The chamber is surrounded by a refractile envelope, which extends well beyond it at both ends, along the longitudinal axis, by a barely colored, somewhat folded portion; a bizarre structure found in various microfossils.
Diameter of the chamber: 40-44 μ. Height of the apical appendage: 6.5 μ. Antero-posterior span (including the extent of the biconical envelope): approximately 100 μ.
Preparation A. VI. Loën.
Trithyrodinium? velatum (Conrad, 1941, p.8–9, pl.1, fig.A ex Sarjeant, 1967b, p.256) Riding and Fensome, 2002, p.24.
Holotype: Conrad, 1941, pl.1, fig.A.
Originally Palaeoperidinium (name not validly published), subsequently Scriniodinium?, thirdly Palaeoperidinium? (combination not validly published), fourthly (and now) Trithyrodinium?.
Questionable assignment: Riding and Fensome (2002, p.24). The name Palaeoperidinium velatum was not validly published in Conrad (1941) since the generic name Palaeoperidinium was not validly published until 1967. Williams et al. (1998, p.550) accepted Sarjeant's (1967b) indirect reference to Conrad (1941) as indication of a type (ICN Article 40.3).
Age: Maastrichtian.
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Original description: [Conrad, 1941] (translated from French):
P. velatum, n. sp. - Pl. 1, fig. A.
The shell is as wide as it is long, angular, bordered by large, concave, rough plates, adorned with small, irregular warts, which give the shell a crenellated outline. The apial and antapical regions are somewhat flattened; the former bears a wide, short, cylindrical process, truncated straight at its free end. This chimney gives P. velatum a pronounced Gonyaulax-like appearance.
The transverse groove could only be observed on its dorsal surface, as the specimen unfortunately did not lend itself to observation, through transparency, from the other surface. It is clearly defined and very deep. It is presumed that its offset, if it truly exists, can only be slight.
The tabulation could not be deciphered. We had to content ourselves with noting the rather vague delineation of a few large, median pentagonal plates located on either side of the transverse groove.
The chamber is surrounded by a refractile envelope, which extends well beyond it at both ends, along the longitudinal axis, by a barely colored, somewhat folded portion; a bizarre structure found in various microfossils.
Diameter of the chamber: 40-44 μ. Height of the apical appendage: 6.5 μ. Antero-posterior span (including the extent of the biconical envelope): approximately 100 μ.
Preparation A. VI. Loën.