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Cyclonephelium distinctum var. psilatum
From Fensome et al., 2019:
Cyclonephelium distinctum var. psilatum (Yu Jingxian and Zhang Wangping, 1980, p.115, pl.6, figs.1–2) Lentin and Williams, 1985, p.86. Holotype: Yu Jingxian and Zhang Wangping, 1980, pl.6, fig.2. Originally Cyclonephelium distinctum var. psilatum, subsequently Cyclonephelium distinctum subsp. psilatum, thirdly Circulodinium distinctum subsp. psilatum. Taxonomic senior synonym (at species rank): Tenua kukebaiensis, according to Fensome et al. (2019a, p.48–49). Age: Turonian–Santonian.
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Original description Yu Jingxian and Zhang Wangping, 1980 [translation Suning Hou 2025]:
Cyclonephelium distinctum var psilatum sp nov.
Holotype: Slide W3-7(-), Plate VI, Figure 2.
Description: The cyst measures 59.8-66.7 µm in length, with the holotype being 66.7 µm, and 48.3-50.6 µm in width, with the holotype width being 50.6 µm.
The cyst is broadly elliptical in outline, tapering toward the apex. The surface is smooth. There are numerous small, solid processes of varying lengths along the equatorial region, with the longest reaching up to 6.9 µm. The tips of the processes are slightly swollen and not interconnected. The processes are less pronounced in the central part of the cyst body and near the cingulum. The archeopyle is apical, and its sutures are irregular.
Comparison: The cyst shape and process characteristics resemble C. distinctum as described by Deflandre & Cookson. However, C. distinctum features longer processes and distinctly granular cyst surfaces, whereas the new species has smaller processes, a relatively smaller cyst body, and a smooth surface.
Stratigraphy: Upper part of the Uytak-Kukbay Formation. 乌依塔克–库克拜上部
Cyclonephelium distinctum var. psilatum (Yu Jingxian and Zhang Wangping, 1980, p.115, pl.6, figs.1–2) Lentin and Williams, 1985, p.86. Holotype: Yu Jingxian and Zhang Wangping, 1980, pl.6, fig.2. Originally Cyclonephelium distinctum var. psilatum, subsequently Cyclonephelium distinctum subsp. psilatum, thirdly Circulodinium distinctum subsp. psilatum. Taxonomic senior synonym (at species rank): Tenua kukebaiensis, according to Fensome et al. (2019a, p.48–49). Age: Turonian–Santonian.
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Original description Yu Jingxian and Zhang Wangping, 1980 [translation Suning Hou 2025]:
Cyclonephelium distinctum var psilatum sp nov.
Holotype: Slide W3-7(-), Plate VI, Figure 2.
Description: The cyst measures 59.8-66.7 µm in length, with the holotype being 66.7 µm, and 48.3-50.6 µm in width, with the holotype width being 50.6 µm.
The cyst is broadly elliptical in outline, tapering toward the apex. The surface is smooth. There are numerous small, solid processes of varying lengths along the equatorial region, with the longest reaching up to 6.9 µm. The tips of the processes are slightly swollen and not interconnected. The processes are less pronounced in the central part of the cyst body and near the cingulum. The archeopyle is apical, and its sutures are irregular.
Comparison: The cyst shape and process characteristics resemble C. distinctum as described by Deflandre & Cookson. However, C. distinctum features longer processes and distinctly granular cyst surfaces, whereas the new species has smaller processes, a relatively smaller cyst body, and a smooth surface.
Stratigraphy: Upper part of the Uytak-Kukbay Formation. 乌依塔克–库克拜上部