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Smolenskiella
From Williams et al., 2017:
[Smolenskiella, Vozzhennikova, 1967, p. 181–182; Emendation: Lentin and Vozzhennikova, 1990, p. 64.
Type species: Smolenskiella crassitheka, Vozzhennikova, 1967 (pl.105, fig.4; pl.106, fig.4)]; emend. Lentin and Vozzhennikova, 1990
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Original description: [Vozzhennikova, 1967]:
Description:
Theca oval-polygonal, divided into unequal parts. Epitheca larger than hypotheca, hemispherical, rounded at the apex or with a short apical process. Hypotheca rounded trapeziform, its small base corresponds to the antapex. Theca tabulate. Plate formula - on epitheca: 4a + 3cp + 6np, on the hypotheca: 5zd + (?2cp) + la. Transverse furrow annulate or slightly spiral. Longitudinal furrow extends from the first apical plate to antapex. Internal body ovoid, ellipsoidal, thin-walled with a smooth surface. Pylome is formed in the place of the second intercalary plate.
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Stover and Evitt, 1978, p. 123:
Comment:
It is impossible to determine from the photomicrographs (Vozzhennikova, 1967, pl. 106, fig. 1-4) whether the paratabulation is interpreted from consistently positioned parasutural ridges or from random folding of the periphragm. In either case, the reported occurrence of six rather than seven precingular paraplates is unusual. This, plus the fact that paraplate 6" is described as small and barely discernible, is not compatible with other peridiniacean genera. Another inconsistency is the identification of paraplate 3" (rather than 4``) directly posterior to paraplate 2a. In all probability Vozzhennikova misinterpreted part of the paratabulation, and a more likely formula for Smolenskiella is 4`, 3a, 7``, X-6c, 5```, ?1p, 1````.
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Emended description:
Lentin and Vozzhennikova, 1990:
Fossil dinoflagellate cysts roundly peridinioid, without distinct dorso-ventral flattening; epicyst slightly dome-shaped with a short, blunt apical horn; hypocyst broadly rectangular, without horns; endocyst oval, with or without small apical horn; circumcavate. Periphragm thin, smooth to finely granulose; endophragm smooth to finely granulose, thicker than periphragm.
Paratabulation indicated by distinct parasutural ridges on periphragm; peridinioid, formula 4`, 3a, 7``, 4-5c, 5```, 2````, ortho-hexa style.
Peri- and endoarcheopyle standard hexa (iso-deltaform) formed by the loss of the 2a paraplate in both wall layers.
Paracingulum is shallow, distinctly bordered by parasutural ridges, may or may not be divided by rectangular paraplates.
Parasulcus is shallow, bordered by distinct parasutural ridges.
Affinities:
The description of the genus Smolenskiella hag been emended to include the correct paratabulation formula and provide details of the archeopyle. There is a superficial resemblance between Smolenskiella and the genus Sirmiodinium Alberti, 1961. However, the distinctly peridinioid paratabulation of Smolenskiella precludes comparison between the two genera.
[Smolenskiella, Vozzhennikova, 1967, p. 181–182; Emendation: Lentin and Vozzhennikova, 1990, p. 64.
Type species: Smolenskiella crassitheka, Vozzhennikova, 1967 (pl.105, fig.4; pl.106, fig.4)]; emend. Lentin and Vozzhennikova, 1990
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Vozzhennikova, 1967]:
Description:
Theca oval-polygonal, divided into unequal parts. Epitheca larger than hypotheca, hemispherical, rounded at the apex or with a short apical process. Hypotheca rounded trapeziform, its small base corresponds to the antapex. Theca tabulate. Plate formula - on epitheca: 4a + 3cp + 6np, on the hypotheca: 5zd + (?2cp) + la. Transverse furrow annulate or slightly spiral. Longitudinal furrow extends from the first apical plate to antapex. Internal body ovoid, ellipsoidal, thin-walled with a smooth surface. Pylome is formed in the place of the second intercalary plate.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Stover and Evitt, 1978, p. 123:
Comment:
It is impossible to determine from the photomicrographs (Vozzhennikova, 1967, pl. 106, fig. 1-4) whether the paratabulation is interpreted from consistently positioned parasutural ridges or from random folding of the periphragm. In either case, the reported occurrence of six rather than seven precingular paraplates is unusual. This, plus the fact that paraplate 6" is described as small and barely discernible, is not compatible with other peridiniacean genera. Another inconsistency is the identification of paraplate 3" (rather than 4``) directly posterior to paraplate 2a. In all probability Vozzhennikova misinterpreted part of the paratabulation, and a more likely formula for Smolenskiella is 4`, 3a, 7``, X-6c, 5```, ?1p, 1````.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Lentin and Vozzhennikova, 1990:
Fossil dinoflagellate cysts roundly peridinioid, without distinct dorso-ventral flattening; epicyst slightly dome-shaped with a short, blunt apical horn; hypocyst broadly rectangular, without horns; endocyst oval, with or without small apical horn; circumcavate. Periphragm thin, smooth to finely granulose; endophragm smooth to finely granulose, thicker than periphragm.
Paratabulation indicated by distinct parasutural ridges on periphragm; peridinioid, formula 4`, 3a, 7``, 4-5c, 5```, 2````, ortho-hexa style.
Peri- and endoarcheopyle standard hexa (iso-deltaform) formed by the loss of the 2a paraplate in both wall layers.
Paracingulum is shallow, distinctly bordered by parasutural ridges, may or may not be divided by rectangular paraplates.
Parasulcus is shallow, bordered by distinct parasutural ridges.
Affinities:
The description of the genus Smolenskiella hag been emended to include the correct paratabulation formula and provide details of the archeopyle. There is a superficial resemblance between Smolenskiella and the genus Sirmiodinium Alberti, 1961. However, the distinctly peridinioid paratabulation of Smolenskiella precludes comparison between the two genera.