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Circulodinium elongatum
From Fensome et al., 2019:
Circulodinium elongatum (He Chengquan, 1991, p.55, pl.9, fig.1) He Chengquan et al., 2009, p.270. Holotype: He Chengquan, 1991, pl.9, fig.1; Fensome et al., 2019a, fig.18E. NOW Tenua? Eisenack. Originally Canningia, subsequently Circulodinium, thirdly (and now) Tenua? Eisenack. Age: Turonian.
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Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
Outline a little conical or elongated pentagon, body nearly circular a clear conical vertex(convex) extend from the top, blunt top. Antapical slightly concave, with two unequal antapical horns, of which the smaller one only tiny display.
Cyst wall relatively thin. Surface with separated short rod-shaped processes and a small amount of particles, length varies, 1-3.5 μm, generally 2 μm.
Archeopyle developed, apical type, (tA) type. The operculum is completely separated and stored in place.
Dimensions:
The holotype length 75 μm, width 62.5 μm.
Affinities:
this new species differs from Canningia senonica in that process are shorter, separated and unequally developed antapical horns, The latter species has longer processes and distantly connected forming an incomplete mesh pattern. The new species differs from C. Colliveri in possessing obviously elongated apical cyst and not deep antapical concave.
Circulodinium elongatum (He Chengquan, 1991, p.55, pl.9, fig.1) He Chengquan et al., 2009, p.270. Holotype: He Chengquan, 1991, pl.9, fig.1; Fensome et al., 2019a, fig.18E. NOW Tenua? Eisenack. Originally Canningia, subsequently Circulodinium, thirdly (and now) Tenua? Eisenack. Age: Turonian.
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Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
Outline a little conical or elongated pentagon, body nearly circular a clear conical vertex(convex) extend from the top, blunt top. Antapical slightly concave, with two unequal antapical horns, of which the smaller one only tiny display.
Cyst wall relatively thin. Surface with separated short rod-shaped processes and a small amount of particles, length varies, 1-3.5 μm, generally 2 μm.
Archeopyle developed, apical type, (tA) type. The operculum is completely separated and stored in place.
Dimensions:
The holotype length 75 μm, width 62.5 μm.
Affinities:
this new species differs from Canningia senonica in that process are shorter, separated and unequally developed antapical horns, The latter species has longer processes and distantly connected forming an incomplete mesh pattern. The new species differs from C. Colliveri in possessing obviously elongated apical cyst and not deep antapical concave.