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Susadinium inflatum
Susadinium inflatum (Bjµrke, 1980) Lentin and Williams, 1985
Originally Facetodinium, subsequently Susadinium.
Taxonomic senior synonym: Susadinium scrofoides, according to Below (1987a, p.120) and Stover and Williams (1987, p.97).
Holotype: Bjµrke, 1980, pl.3, fig.1-6
Locus typicus: Knorringfjellet, Spitsbergen
Stratum typicum: Toarcian
Original description: Bjµrke, 1980, p. 69-70: Facetodinium inflatum
Diagnosis: dinoflagellate cysts of the genus Facetodinium with an elongated, basically pentagonal outline in dorso-ventral view, modified by prominent intratabular inflations in the pre- and post-cingular paraplate series and on the second antapical paraplate. Cyst dorso-ventrally flattened. Autophragm ornamented with blunt processes less than 1 µm high, somewhat coarser ornamentation on inflations. Epicyst and hypocyst separated by a shallow to deeply constricted paracingulum. Parasulcus not demarcated. Archaeopyle formed by single mid-dorsal intercalary paraplate with haxagonal outline (geniculate).
Size: 25-50 µm long, 20-33 µm wide in dorso-ventral view, 17-31 µm wide in lateral view.
Description: Small dinoflagellate cyst with an elongated outline dominated by prominent rounded to plateau-like inflations developed on paraplates of the pre- and postcingular series and on the second antapical paraplate. Reduced inflations are present on the first antapical paraplate and on paraplates 2" and 5". The paratabulation pattern has been interpreted from the number and position of inflations. Observations of parasutures in dorsal area clearly support this interpretation. Middorsal intercalary paraplate with hexagonal outline forms the geniculate archaeopyle. Archaeopyle commonly detached. Parasutures separating the paraplates of the apical series have not been observed. Cyst dorso-ventrally flattened. Ornamentation of evenly distributed blunt processes less than 1 µm present, somewhat coarser ornamentation on inflations. Paracingulum marked by a shallow to deep equatorial constriction, in most specimens characteristically deep. Parasulcus not indicated.
Affinities:
Bjµrke, 1980, p. 71: Facetodinium inflatum
Facetodinium inflatum shows an overall similarity with Susadinium scrofoides Dörhöfer and Davies 1980, described from the Savik Formation of Arctic Canada. However, the reflected tabulation as interpreted from the number and distribution of inflations and the mode of archaeopyle formation differ from that observed in F. inflatum.
Originally Facetodinium, subsequently Susadinium.
Taxonomic senior synonym: Susadinium scrofoides, according to Below (1987a, p.120) and Stover and Williams (1987, p.97).
Holotype: Bjµrke, 1980, pl.3, fig.1-6
Locus typicus: Knorringfjellet, Spitsbergen
Stratum typicum: Toarcian
Original description: Bjµrke, 1980, p. 69-70: Facetodinium inflatum
Diagnosis: dinoflagellate cysts of the genus Facetodinium with an elongated, basically pentagonal outline in dorso-ventral view, modified by prominent intratabular inflations in the pre- and post-cingular paraplate series and on the second antapical paraplate. Cyst dorso-ventrally flattened. Autophragm ornamented with blunt processes less than 1 µm high, somewhat coarser ornamentation on inflations. Epicyst and hypocyst separated by a shallow to deeply constricted paracingulum. Parasulcus not demarcated. Archaeopyle formed by single mid-dorsal intercalary paraplate with haxagonal outline (geniculate).
Size: 25-50 µm long, 20-33 µm wide in dorso-ventral view, 17-31 µm wide in lateral view.
Description: Small dinoflagellate cyst with an elongated outline dominated by prominent rounded to plateau-like inflations developed on paraplates of the pre- and postcingular series and on the second antapical paraplate. Reduced inflations are present on the first antapical paraplate and on paraplates 2" and 5". The paratabulation pattern has been interpreted from the number and position of inflations. Observations of parasutures in dorsal area clearly support this interpretation. Middorsal intercalary paraplate with hexagonal outline forms the geniculate archaeopyle. Archaeopyle commonly detached. Parasutures separating the paraplates of the apical series have not been observed. Cyst dorso-ventrally flattened. Ornamentation of evenly distributed blunt processes less than 1 µm present, somewhat coarser ornamentation on inflations. Paracingulum marked by a shallow to deep equatorial constriction, in most specimens characteristically deep. Parasulcus not indicated.
Affinities:
Bjµrke, 1980, p. 71: Facetodinium inflatum
Facetodinium inflatum shows an overall similarity with Susadinium scrofoides Dörhöfer and Davies 1980, described from the Savik Formation of Arctic Canada. However, the reflected tabulation as interpreted from the number and distribution of inflations and the mode of archaeopyle formation differ from that observed in F. inflatum.