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Pterodinium
From Williams et al., 2017:
[Pterodinium, Eisenack, 1958a, p. 395; Emendations: Yun Hyesu, 1981, p. 12; Sarjeant, 1985a, p. 70–72 — however, see Jan du Chêne et al. (1986a, p.273).
Type species: Pterodinium aliferum, Eisenack, 1958a (pl.24, fig.6; text-fig.6)] ; emend. Sarjeant, 1985
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Original description: [Eisenack, 1958]: (Translation: Stover and Evitt, 1978, p. 182):
Diagnosis:
Shell oval (also globular?), with a tabulation in which a system similar to a transverse and longitudinal furrow is distinctly developed. Borders of fields formed by broad, winged edges.
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Modified description:
Stover and Evitt, 1978, p. 182-183:
Synopsis:
Cysts proximochorate; body subspherical with relatively high parasutural septa; paratabulation probably gonyaulacacean, but number and exact shapes of most paraplates unknown.
Description:
Shape: Body subspherical.
Wall relationships: Probably autophragm only.
Wall features: Parasutural septa relatively high, or fairly uniform in height, and with nearly smooth or serrate edges. Autophragm between septa evidently smooth.
Paratabulation: Not known completely, probably gonyaulacacean; dorsal paraplates appear to conform in number and shape to standard gonyaulacacean pattern; details of other paraplates unknown.
Archaeopyle: Perecingular, Type P (3`` only); operculum free.
Paracingulum: Indicated on dorsal surface by three subrectangular paraplates; on ventral surface by transverse, parallel, parasutural septa.
Parasulcus: Indicated by two subparallel longitudinal septa; epicystal part shorter than hypocystal part.
Size: Intermediate.
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Emended descriptions:
Yun, 1981: (Translation: Sarjeant, 1985, p. 71)
Diagnosis:
A pterochorate cyst, oval to circular in outline, subdivided into paraplates by by high crests(1/4 of the central body breadth), with a precingular archaeopyle. The boundary crests appr. constant in height on a single specimen and may be distally denticulate. In gonal positions, where, where two or three crest intersect, no processes are formed, so that these places are equally high or even lower than the sutural positions. Paracingulum and parsulcus may be subdivided. The genus Pterodinium exhibits no apical or antapical horn. The pattern of tabulation reads: 3-4`, 6``, 0-1a, 6c, 1p, 5```, 1````.
Affinities:
Pterodinium differs from Gonyaulacysta in the absence of an apical horn and the presence of the high septa. Pterodinium differs from Leptodinium also in the delicate, parasutural septa, which generally attain a height of over 1/4 of the central body diameter. Furthermore, Pterodinium has very thin, equally high septa, whereas Leptodinium has low, simple, thick edges, ridges, rarely partially high edges, or rows of distally connected spines, which may be higher gonally.
Pterodinium cornutum, with an apical horn and irregularly high sutural edges, and Pterodinium magnoserratum, with an apical horn, are transferred to Gonyaulacysta.
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Sarjeant, 1985:
Diagnosis:
Proximochorate, murochorate dinoflagellate cysts, acavate. An apical horn of small to moderate height may be present or absent; antapical and lateral horns are lacking. Ambitus rounded to subpolygonal; epitract and hypotract of equal or similar size and shape. Height of crests defining principal paraplates relatively constant on any single specimen, but variable within or between species, in the range 20-30% of the central body breadth. Cingulum and sulcus may be subdivided by lower crests or ridges; the sulcus may be undivided.
Paratabulation: 0-?2pr, 4`, 0-1a, 6``, 6-?7c, 5-6```, 1-2p, 0-1pv, 1````, 0-6 or ?7s. Paraplate 4` is roughly quadrate, having a long contact with a roughly quadrate 6``. The crest between 4` and 6`` intersects the right lateral crets bounding 1` in a position almost level with or just anterior to, the junction of the latter paraplate with the sulcus. Gonal spines of small to moderate height present or absent: if present, less high than (and often concealed by) the crests. Surface of periphragm smooth, granular, nodose, punctate or reticulate.
Archaeopyle single-plated precingular (type P), formed by the loss of paraplate 3``; operculum reduced.
[Pterodinium, Eisenack, 1958a, p. 395; Emendations: Yun Hyesu, 1981, p. 12; Sarjeant, 1985a, p. 70–72 — however, see Jan du Chêne et al. (1986a, p.273).
Type species: Pterodinium aliferum, Eisenack, 1958a (pl.24, fig.6; text-fig.6)] ; emend. Sarjeant, 1985
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eisenack, 1958]: (Translation: Stover and Evitt, 1978, p. 182):
Diagnosis:
Shell oval (also globular?), with a tabulation in which a system similar to a transverse and longitudinal furrow is distinctly developed. Borders of fields formed by broad, winged edges.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt, 1978, p. 182-183:
Synopsis:
Cysts proximochorate; body subspherical with relatively high parasutural septa; paratabulation probably gonyaulacacean, but number and exact shapes of most paraplates unknown.
Description:
Shape: Body subspherical.
Wall relationships: Probably autophragm only.
Wall features: Parasutural septa relatively high, or fairly uniform in height, and with nearly smooth or serrate edges. Autophragm between septa evidently smooth.
Paratabulation: Not known completely, probably gonyaulacacean; dorsal paraplates appear to conform in number and shape to standard gonyaulacacean pattern; details of other paraplates unknown.
Archaeopyle: Perecingular, Type P (3`` only); operculum free.
Paracingulum: Indicated on dorsal surface by three subrectangular paraplates; on ventral surface by transverse, parallel, parasutural septa.
Parasulcus: Indicated by two subparallel longitudinal septa; epicystal part shorter than hypocystal part.
Size: Intermediate.
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Emended descriptions:
Yun, 1981: (Translation: Sarjeant, 1985, p. 71)
Diagnosis:
A pterochorate cyst, oval to circular in outline, subdivided into paraplates by by high crests(1/4 of the central body breadth), with a precingular archaeopyle. The boundary crests appr. constant in height on a single specimen and may be distally denticulate. In gonal positions, where, where two or three crest intersect, no processes are formed, so that these places are equally high or even lower than the sutural positions. Paracingulum and parsulcus may be subdivided. The genus Pterodinium exhibits no apical or antapical horn. The pattern of tabulation reads: 3-4`, 6``, 0-1a, 6c, 1p, 5```, 1````.
Affinities:
Pterodinium differs from Gonyaulacysta in the absence of an apical horn and the presence of the high septa. Pterodinium differs from Leptodinium also in the delicate, parasutural septa, which generally attain a height of over 1/4 of the central body diameter. Furthermore, Pterodinium has very thin, equally high septa, whereas Leptodinium has low, simple, thick edges, ridges, rarely partially high edges, or rows of distally connected spines, which may be higher gonally.
Pterodinium cornutum, with an apical horn and irregularly high sutural edges, and Pterodinium magnoserratum, with an apical horn, are transferred to Gonyaulacysta.
-----------------------------------------------
Sarjeant, 1985:
Diagnosis:
Proximochorate, murochorate dinoflagellate cysts, acavate. An apical horn of small to moderate height may be present or absent; antapical and lateral horns are lacking. Ambitus rounded to subpolygonal; epitract and hypotract of equal or similar size and shape. Height of crests defining principal paraplates relatively constant on any single specimen, but variable within or between species, in the range 20-30% of the central body breadth. Cingulum and sulcus may be subdivided by lower crests or ridges; the sulcus may be undivided.
Paratabulation: 0-?2pr, 4`, 0-1a, 6``, 6-?7c, 5-6```, 1-2p, 0-1pv, 1````, 0-6 or ?7s. Paraplate 4` is roughly quadrate, having a long contact with a roughly quadrate 6``. The crest between 4` and 6`` intersects the right lateral crets bounding 1` in a position almost level with or just anterior to, the junction of the latter paraplate with the sulcus. Gonal spines of small to moderate height present or absent: if present, less high than (and often concealed by) the crests. Surface of periphragm smooth, granular, nodose, punctate or reticulate.
Archaeopyle single-plated precingular (type P), formed by the loss of paraplate 3``; operculum reduced.