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Scriniodinium parvimarginatum
Scriniodinium parvimarginatum (Cookson and Eisenack, 1958) Eisenack, 1967
Originally Gymnodinium, subsequently (and now) Scriniodinium.
Holotype: Cookson and Eisenack, 1958, pl.1, fig.6; Jan du Chêne et al.,1986, pl.112, fig.10-12
Locus typicus: Broome, W Australia
Stratum typicum: Late Jurassic
Original description: Cookson and Eisenack, 1958, p. 24-25: Gymnodinium parvimarginatum
Theca almost circular to broadly oval in outline, divided somewhat unequally by a straight and narrow transverse furrow into a rather shorter and occasionally slightly pointed epitheca and a longer rounded hypotheca. Inner capsule not entirely filling the thin membrane but surrounded by a narrow margin c. 5 µm wide.
As in the Australian species G. crystallinum and G. luridum, a relatively large pylome extends vertically from the transverse girdle almost to the apex of the epitheca.
Dimensions: Type: 90 x 90 µm. Range 76-100 x 76-100 µm.
Affinities:
Cookson and Eisenack, 1958, p. 25: Gymnodinium parvimarginatum
This species is distinguished by the circular outline, narrow margin (c.5 µm), the width of which, in the Australian and New Guinea species of G. crystallinum is 5-15 µm and in G. luridum 7-10 µm, and its flatter form.
Originally Gymnodinium, subsequently (and now) Scriniodinium.
Holotype: Cookson and Eisenack, 1958, pl.1, fig.6; Jan du Chêne et al.,1986, pl.112, fig.10-12
Locus typicus: Broome, W Australia
Stratum typicum: Late Jurassic
Original description: Cookson and Eisenack, 1958, p. 24-25: Gymnodinium parvimarginatum
Theca almost circular to broadly oval in outline, divided somewhat unequally by a straight and narrow transverse furrow into a rather shorter and occasionally slightly pointed epitheca and a longer rounded hypotheca. Inner capsule not entirely filling the thin membrane but surrounded by a narrow margin c. 5 µm wide.
As in the Australian species G. crystallinum and G. luridum, a relatively large pylome extends vertically from the transverse girdle almost to the apex of the epitheca.
Dimensions: Type: 90 x 90 µm. Range 76-100 x 76-100 µm.
Affinities:
Cookson and Eisenack, 1958, p. 25: Gymnodinium parvimarginatum
This species is distinguished by the circular outline, narrow margin (c.5 µm), the width of which, in the Australian and New Guinea species of G. crystallinum is 5-15 µm and in G. luridum 7-10 µm, and its flatter form.