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Rhombodinium kunlunense
Rhombodinium ?kunlunense He Chengquan, 1991, p.98–99. pl.37, figs.3–6. Holotype: He Chengquan, 1991, pl.37, fig.6. Questionable assignment: Williams et al. (2015, p.311). Age: late Turonian–middle Eocene.
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: The cyst is dorsal-ventral flattened, outline pentagonal, horizontal elongation, width slightly larger than the length, upper and lower cyst are nearly equal. Epicyst triangular, sides slightly convex, with an apical horn, the apex is conical or papillary, 7.5μm long. Hypocyst is nearly trapezoidal, sides concave, bottom straight or slightly concave, with two nearly equal antapical horns, papillary, 8-12μm long, far apart from each other (32.5-50μm). 2 lateral horns are strong, tapering distally, 6-12μm long, end concave or smooth. The cingulum is at the equator position, more clearly on both sides of the corner. The outer wall surface is fine granular or smooth. The inner body contour is circular pentagonal, and occasionally circular rhombus, obviously extending into both lateral horns, the surface is dense granular or rough; It is separated from the outer wall by a narrow outer cavity, the cavity width is 2-3.5μm laterally. The archeopyle is intercalary, outline round square, length and width are nearly equal or length smaller than the width. The operculum is completely separated and preserved in situ. Cyst length 100-112 μm, width 102.5-117μm, inner body length 72-87 5μm, width 75-97.5μm (measured 4), holotype length 112μm, width 117μm, the inner body length 87.5μm, width 97.5μm, apical horn length of 7.5μm, antapical horn length 12ρm, lateral horn length 8.5 -12μm.
Comparison: The new species is similar to Rhombodinium wuqiaense in appearance, but the outer surface of the former is nearly smooth, apical, antapical horns are underdeveloped, often papillary, inner body circle pentagonal rather than nearly circular.
Location and stratigraphy: Wuqia County Basebulak, Urukqiati and Shache County Qu Ruimu; Wulagen fm.
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: The cyst is dorsal-ventral flattened, outline pentagonal, horizontal elongation, width slightly larger than the length, upper and lower cyst are nearly equal. Epicyst triangular, sides slightly convex, with an apical horn, the apex is conical or papillary, 7.5μm long. Hypocyst is nearly trapezoidal, sides concave, bottom straight or slightly concave, with two nearly equal antapical horns, papillary, 8-12μm long, far apart from each other (32.5-50μm). 2 lateral horns are strong, tapering distally, 6-12μm long, end concave or smooth. The cingulum is at the equator position, more clearly on both sides of the corner. The outer wall surface is fine granular or smooth. The inner body contour is circular pentagonal, and occasionally circular rhombus, obviously extending into both lateral horns, the surface is dense granular or rough; It is separated from the outer wall by a narrow outer cavity, the cavity width is 2-3.5μm laterally. The archeopyle is intercalary, outline round square, length and width are nearly equal or length smaller than the width. The operculum is completely separated and preserved in situ. Cyst length 100-112 μm, width 102.5-117μm, inner body length 72-87 5μm, width 75-97.5μm (measured 4), holotype length 112μm, width 117μm, the inner body length 87.5μm, width 97.5μm, apical horn length of 7.5μm, antapical horn length 12ρm, lateral horn length 8.5 -12μm.
Comparison: The new species is similar to Rhombodinium wuqiaense in appearance, but the outer surface of the former is nearly smooth, apical, antapical horns are underdeveloped, often papillary, inner body circle pentagonal rather than nearly circular.
Location and stratigraphy: Wuqia County Basebulak, Urukqiati and Shache County Qu Ruimu; Wulagen fm.