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Diconodinium distinctum
From Fensome et al., 2019:
Diconodinium distinctum Jain and Millepied, 1975, p.154–155, pl.6, figs.98–99. Holotype: Jain and Millepied, 1975, pl.6, fig.98.
Age: Campanian–Maastrichtian.
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Original description: [Jain and Millepied, 1975]:
Diconodinium distinctum sp. nov. (PI. 6, Figs. 98-99)
Holotype - PI. 6, Fig. 98; Slide No. 8459-5.
Type locality - Bore hole no. CM-I; depth 1055.30 metres; Senegal Basin, W. Africa.
Horizon - Campanian-Maestrichtian.
Diagnosis - Shell fusiform without capsule; girdle circular, distinct, dividing unequally into larger epitract than hypotract. Clear lines run from apex to antapex forming distinct logitudinal aperture on one side, broader near girdle. Shell membrane thickly ornamented with bifid, short spines, arranged in longitudinal lines giving an indication of tabulation. Apex and antapex pointed.
Measurements
Shell length: holotype: 78 μm, range: 70-90 μm
Shell width: holotype: 33 μm, range: 30-60 μm
Spine length: holotype: 1.5 μm, range: 1.5-3 μm
Comparison-Diconodinium distinctum sp. nov. compares closest with D. dispersum (Cookson & Eisenack) Eisenack & Cookson (1960), D. multispinum (Defandre & Cookson) Eisenack & Cookson (1960), D. pelliferum (Cookson & Eisenack) Eisenack & Cookson (1960) in having spinose shell surface. But differs in its distinct longitudinal aperture running from pole to pole and slight indication of tabulation. The aperture is comparable to archaeopyle of dinoflagellates though uniquc in its situation. It is formed from plate detachment. The indication of tabulation, cingulum and longitudinal archaeopyle suggests its inclusion in dinoflagellate and confirm the view of CoOKSON AND EIsENACK (1960, p. 490).
Diconodinium distinctum Jain and Millepied, 1975, p.154–155, pl.6, figs.98–99. Holotype: Jain and Millepied, 1975, pl.6, fig.98.
Age: Campanian–Maastrichtian.
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Original description: [Jain and Millepied, 1975]:
Diconodinium distinctum sp. nov. (PI. 6, Figs. 98-99)
Holotype - PI. 6, Fig. 98; Slide No. 8459-5.
Type locality - Bore hole no. CM-I; depth 1055.30 metres; Senegal Basin, W. Africa.
Horizon - Campanian-Maestrichtian.
Diagnosis - Shell fusiform without capsule; girdle circular, distinct, dividing unequally into larger epitract than hypotract. Clear lines run from apex to antapex forming distinct logitudinal aperture on one side, broader near girdle. Shell membrane thickly ornamented with bifid, short spines, arranged in longitudinal lines giving an indication of tabulation. Apex and antapex pointed.
Measurements
Shell length: holotype: 78 μm, range: 70-90 μm
Shell width: holotype: 33 μm, range: 30-60 μm
Spine length: holotype: 1.5 μm, range: 1.5-3 μm
Comparison-Diconodinium distinctum sp. nov. compares closest with D. dispersum (Cookson & Eisenack) Eisenack & Cookson (1960), D. multispinum (Defandre & Cookson) Eisenack & Cookson (1960), D. pelliferum (Cookson & Eisenack) Eisenack & Cookson (1960) in having spinose shell surface. But differs in its distinct longitudinal aperture running from pole to pole and slight indication of tabulation. The aperture is comparable to archaeopyle of dinoflagellates though uniquc in its situation. It is formed from plate detachment. The indication of tabulation, cingulum and longitudinal archaeopyle suggests its inclusion in dinoflagellate and confirm the view of CoOKSON AND EIsENACK (1960, p. 490).