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Stomodinium
From Williams et al., 2017:
[Stomodinium, He Cheng-quan, 1984a, p. 770, 774
Type species: Stomodinium crassum, He Cheng-quan, 1984a (pl.1, fig.12)]
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Original description: [He Cheng-quan, 1984a]:
Diagnosis:
Cysts proximochorate, acavate. Body subspherical to elliptical in outline, lacking apical and antapical horns. Wall usually very thick surface with granulation, rugae, tuberculation and a short slender sutural spine. Paratabulation probably gonyaulacacean- paraplates incompletely indicated by sutural features. Cingulum more or less indicated by the alignment of ornamentation or spines in equatorial area.
Archaeopyle precingular, Type P (3" only). Operculum free but often adherent in situ.
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Chen et al., p. 30:
Remarks:
The alignment of surface features is not evident on the illustrated specimens, thus the basis for the parasutural features depicted by He Cheng-quan, 1984, is not clear. Without explicit indications of paratabulation, retention of Stomodinium as a genus distinct from Xenicodinium appears to be unjustified. Trichodinium Eisenack and Cookson, 1960 emend. Clarke and Verdier, 1967 differs from Stomodinium in the nature of the ornamentation and in possessing an apical horn.
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GSC: (GSC provisional translation: courtesy R. Fensome):
Cysts proximochorate, acavate. Body subspherical to ellipsoidal. No apical or antapical horns. Walls normally very thick; surface has low-relief ornamentation such as granules, rugae and verrucae, as well as sutural features - short fine processes (spines) distributed along the suture. Paratabulation may very likely be gonyaulacacean. Cingulum displayed to a greater or lesser degree by equatorial decoration or distribution of processes. Archaeopyle precingular, type P.
Discussion:
This genus is characterized by its lack of apical and antapical horns, its thick walls, the distribution of short processes along the sutural zone, the presence of a cingulum, and its precingular archaeopyle (type P). It bears no resemblance to any of the more than 70 genera with precingular archaeopyles presently known to us.
[Stomodinium, He Cheng-quan, 1984a, p. 770, 774
Type species: Stomodinium crassum, He Cheng-quan, 1984a (pl.1, fig.12)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Cheng-quan, 1984a]:
Diagnosis:
Cysts proximochorate, acavate. Body subspherical to elliptical in outline, lacking apical and antapical horns. Wall usually very thick surface with granulation, rugae, tuberculation and a short slender sutural spine. Paratabulation probably gonyaulacacean- paraplates incompletely indicated by sutural features. Cingulum more or less indicated by the alignment of ornamentation or spines in equatorial area.
Archaeopyle precingular, Type P (3" only). Operculum free but often adherent in situ.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Chen et al., p. 30:
Remarks:
The alignment of surface features is not evident on the illustrated specimens, thus the basis for the parasutural features depicted by He Cheng-quan, 1984, is not clear. Without explicit indications of paratabulation, retention of Stomodinium as a genus distinct from Xenicodinium appears to be unjustified. Trichodinium Eisenack and Cookson, 1960 emend. Clarke and Verdier, 1967 differs from Stomodinium in the nature of the ornamentation and in possessing an apical horn.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
GSC: (GSC provisional translation: courtesy R. Fensome):
Cysts proximochorate, acavate. Body subspherical to ellipsoidal. No apical or antapical horns. Walls normally very thick; surface has low-relief ornamentation such as granules, rugae and verrucae, as well as sutural features - short fine processes (spines) distributed along the suture. Paratabulation may very likely be gonyaulacacean. Cingulum displayed to a greater or lesser degree by equatorial decoration or distribution of processes. Archaeopyle precingular, type P.
Discussion:
This genus is characterized by its lack of apical and antapical horns, its thick walls, the distribution of short processes along the sutural zone, the presence of a cingulum, and its precingular archaeopyle (type P). It bears no resemblance to any of the more than 70 genera with precingular archaeopyles presently known to us.