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Rhombodinium draco ssp. quadratum
Rhombodinium draco ssp. quadratum He Chengquan, 1991
Holotype: He Chengquan, 1991, pl.38, fig.1
Age: Late Eocene
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: The cyst is dorsal-ventral flattened, outline square or kite-shaped, laterally elongated, usually width larger than length or nearly equal, near the top, extending apex angle, conical, length 10-20μm, tip slightly sharp. 2 lateral horns protrudes strongly on the sides, length 12.5-28μm, distally slightly thin, the end is open or incision-shaped. Two antapical horns are confluent, one is conical, length 9-25μm, the end is pointed, the other horn is convex like or stair-like, almost completely degenerated. Cingulum is very clear on both lateral horns, on the dorsal ventral side it is marked by the two cross-wrinkles or lines between 2 lateral horns. Outer wall surfaces are grainy or smooth, but there are often visible particles on the surface of lateral horns and (or) apical horn. The inner contour is circle square or a circle rhombus, width larger than length or nearly equal, usually convex to the lateral horns, divided into two equal halves by the cingulum, the wall surface is fine granular, the edge is generally significant granular, In particular, the particles near the horns are developed, and connected to each other forming granular wrinkles; In some individual specimens, there are some precipitation materials on the inner body horn surface , especially accumulating at the lateral horns palce to papillary-shaped-low-conical. The archeopyle is intercalary, round trapezoid-square. The operculum is completely detached, usually in situ preserved or adhered to the edge of the archeopyle. Cyst length 110-152μm, width 118-158μm, body length 75-102. 5 μm, width 82.5-102.5μm (measured 10); Holotype length 152μm, width 158μm, inner body length 102.5μm, width 102.5μm, apical horn length 20μm, lateral horn length 25-28μm, big antapical horn length 27 .5μm.
Location and stratigraphy: Wuqia County Basebulak; Basebulak fm member second and third.
Holotype: He Chengquan, 1991, pl.38, fig.1
Age: Late Eocene
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: The cyst is dorsal-ventral flattened, outline square or kite-shaped, laterally elongated, usually width larger than length or nearly equal, near the top, extending apex angle, conical, length 10-20μm, tip slightly sharp. 2 lateral horns protrudes strongly on the sides, length 12.5-28μm, distally slightly thin, the end is open or incision-shaped. Two antapical horns are confluent, one is conical, length 9-25μm, the end is pointed, the other horn is convex like or stair-like, almost completely degenerated. Cingulum is very clear on both lateral horns, on the dorsal ventral side it is marked by the two cross-wrinkles or lines between 2 lateral horns. Outer wall surfaces are grainy or smooth, but there are often visible particles on the surface of lateral horns and (or) apical horn. The inner contour is circle square or a circle rhombus, width larger than length or nearly equal, usually convex to the lateral horns, divided into two equal halves by the cingulum, the wall surface is fine granular, the edge is generally significant granular, In particular, the particles near the horns are developed, and connected to each other forming granular wrinkles; In some individual specimens, there are some precipitation materials on the inner body horn surface , especially accumulating at the lateral horns palce to papillary-shaped-low-conical. The archeopyle is intercalary, round trapezoid-square. The operculum is completely detached, usually in situ preserved or adhered to the edge of the archeopyle. Cyst length 110-152μm, width 118-158μm, body length 75-102. 5 μm, width 82.5-102.5μm (measured 10); Holotype length 152μm, width 158μm, inner body length 102.5μm, width 102.5μm, apical horn length 20μm, lateral horn length 25-28μm, big antapical horn length 27 .5μm.
Location and stratigraphy: Wuqia County Basebulak; Basebulak fm member second and third.