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Apteodinium tenuicinctum
Apteodinium tenuicinctum, He Chengquan, 1991
Holotype: He Chengquan, 1991, pl.5, fig.33; text-fig.17.
Location and stratigraphy: Wuqian County Basebulak; Wulagen fm and Basebulak fm member two and three.
Age: Middle-Late Eocene
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Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The cyst is oval, length larger than width, without apical antapical horns, the two poles wide circle, the size and shape of the upper and lower cysts are similar. Thin wall, single layer, fine granular surface with large wrinkles. Cingulum equatorial position, spiral, narrow, width 4 μm, its edges are marked by fine ridges. Lack of sulcus.
Archeopyle precingular, P-type, formed by the third precingular plate movement. Operculum fell off.
Dimensions:
Cyst length of -65 μm, width 46-52 μm (measured 2); Holotype length 65 μm, width 52μm.
Affinities/Comparison:
This species differs from Apteodinium granorugosum, A. sparsum, in a narrower cyst, weak cingulum and its edge ridge not extending out of the outline.
Holotype: He Chengquan, 1991, pl.5, fig.33; text-fig.17.
Location and stratigraphy: Wuqian County Basebulak; Wulagen fm and Basebulak fm member two and three.
Age: Middle-Late Eocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The cyst is oval, length larger than width, without apical antapical horns, the two poles wide circle, the size and shape of the upper and lower cysts are similar. Thin wall, single layer, fine granular surface with large wrinkles. Cingulum equatorial position, spiral, narrow, width 4 μm, its edges are marked by fine ridges. Lack of sulcus.
Archeopyle precingular, P-type, formed by the third precingular plate movement. Operculum fell off.
Dimensions:
Cyst length of -65 μm, width 46-52 μm (measured 2); Holotype length 65 μm, width 52μm.
Affinities/Comparison:
This species differs from Apteodinium granorugosum, A. sparsum, in a narrower cyst, weak cingulum and its edge ridge not extending out of the outline.