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Charlesdowniea rhomboidalis
Charlesdowniea rhomboidalis, (He Chengquan, 1991), Lentin and Williams, 1993
Originally Kisselevia, subsequently Charlesdowniea, thirdly (and now) Michouxdinium?
Holotype: He Chengquan, 1991, pl.35, figs.11-12
Location and stratigraphy: Wuqia County Basebulak, Wulagen fm.
Age: Middle Eocene
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Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The outline is round diamond or nearly square, length and width are nearly equal. Upper cyst triangular, margin nearly straight or slightly convex, with or without a slightly pointed apical horn. The hypocyst is almost equal to the epicyst, semi-circular, slightly convex side, antapex smooth, lack of antapical horns. Two sides of the cyst waist are smooth, no lateral horns.
The cingulum is fuzzy, located in the equatorial zone, concave on the side, about 7.5 μm wide.
No sulcus displayed.
Cyst wall has two layers, nearly equal thickness, the outer wall surface with a number of linear processes; processes are smooth, straight or curved, 5-12 μm long. The ends are connected by not continuous enough linear trabecula, showing obvious fence on the cyst contour; The process distribution is likely to be intraplate, the local display of the fuzzy area, but the detailed tabulation can not be determined; the outer surface between the processes is smooth or with small particles. The inner body and the outer wall contours are the same, wall thickness is about 1 μm, smooth surface; It and the outer wall are close to each other or separated by a narrow external cavate.
The archeopyle is intercalary style, the outline is trapezoid. The operculum has been separated and preserved in place.
Dimensions:
Cyst length 83-96 μm, width 75-96 μm, the inner body length 74-85 μm, width 68-87 μm (measured 3), the holotype total length is 96 μm, width 96 μm, The inner body is 85 μm long, 87 μm wide.
Affinities:
The new species is different from Kisselovia ornata subsp. Reticulata (Vozzhennikova) in that the cyst is round rhombus, lacking antapical horns and lateral horns.
Originally Kisselevia, subsequently Charlesdowniea, thirdly (and now) Michouxdinium?
Holotype: He Chengquan, 1991, pl.35, figs.11-12
Location and stratigraphy: Wuqia County Basebulak, Wulagen fm.
Age: Middle Eocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The outline is round diamond or nearly square, length and width are nearly equal. Upper cyst triangular, margin nearly straight or slightly convex, with or without a slightly pointed apical horn. The hypocyst is almost equal to the epicyst, semi-circular, slightly convex side, antapex smooth, lack of antapical horns. Two sides of the cyst waist are smooth, no lateral horns.
The cingulum is fuzzy, located in the equatorial zone, concave on the side, about 7.5 μm wide.
No sulcus displayed.
Cyst wall has two layers, nearly equal thickness, the outer wall surface with a number of linear processes; processes are smooth, straight or curved, 5-12 μm long. The ends are connected by not continuous enough linear trabecula, showing obvious fence on the cyst contour; The process distribution is likely to be intraplate, the local display of the fuzzy area, but the detailed tabulation can not be determined; the outer surface between the processes is smooth or with small particles. The inner body and the outer wall contours are the same, wall thickness is about 1 μm, smooth surface; It and the outer wall are close to each other or separated by a narrow external cavate.
The archeopyle is intercalary style, the outline is trapezoid. The operculum has been separated and preserved in place.
Dimensions:
Cyst length 83-96 μm, width 75-96 μm, the inner body length 74-85 μm, width 68-87 μm (measured 3), the holotype total length is 96 μm, width 96 μm, The inner body is 85 μm long, 87 μm wide.
Affinities:
The new species is different from Kisselovia ornata subsp. Reticulata (Vozzhennikova) in that the cyst is round rhombus, lacking antapical horns and lateral horns.