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Cordosphaeridium operculatum
Cordosphaeridium operculatum He Chengquan, 1991
He Chengquan, 1991, included this species in Cordosphaeridium subgen. Tarimocystium.
Holotype: He Chengquan, 1991, pl.14, fig.5, text-fig.40b
Age: Middle Eocene
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: Oval body. Wall thickness 2μm, inner and outer wall are close to each other. The surfacis dense short fibrous-, incomplete fine reticular. Process intratabular, one on each plate, formed by the outer wall, with fibrous structure; Processes are short, closed or open distally; One apical process conical, about 5μm long, antapical processes low round mushroom pileus , about 4.5μm long, base 20-24μm wide, sometimes not centered. Cingulum process unknown; Pre-postcingular processes are short cylindrical or truncated conical, about 6.5μm long, but mostly crumpled state. The archeopyle is large, probably precingular, its edge is sub-angular (as holotype) or nearly circular, occasionally incised. Operculum in situ or adhered to the edge of the archeopyle.
Total length 80-85μm, width 75-84μm (measured 3); the total length of the holotype is 85μm, width 75μm, the process length 5μm, antapical process length 4.5μm, base width 20μm.
Note: Although the cingulum process of this species is unknown and the archeopyle is large, but the archeopyle shape is like a horseshoe with incision and there is only one process on the operculum, so the archeopyle is undoubtedly precingular.
Location and stratigraphy: Wuqia County Basebulak; Wulagen fm.
He Chengquan, 1991, included this species in Cordosphaeridium subgen. Tarimocystium.
Holotype: He Chengquan, 1991, pl.14, fig.5, text-fig.40b
Age: Middle Eocene
Description from He Chengquan, 1991, translated by Suning Hou, 07-01-2019
Description: Oval body. Wall thickness 2μm, inner and outer wall are close to each other. The surfacis dense short fibrous-, incomplete fine reticular. Process intratabular, one on each plate, formed by the outer wall, with fibrous structure; Processes are short, closed or open distally; One apical process conical, about 5μm long, antapical processes low round mushroom pileus , about 4.5μm long, base 20-24μm wide, sometimes not centered. Cingulum process unknown; Pre-postcingular processes are short cylindrical or truncated conical, about 6.5μm long, but mostly crumpled state. The archeopyle is large, probably precingular, its edge is sub-angular (as holotype) or nearly circular, occasionally incised. Operculum in situ or adhered to the edge of the archeopyle.
Total length 80-85μm, width 75-84μm (measured 3); the total length of the holotype is 85μm, width 75μm, the process length 5μm, antapical process length 4.5μm, base width 20μm.
Note: Although the cingulum process of this species is unknown and the archeopyle is large, but the archeopyle shape is like a horseshoe with incision and there is only one process on the operculum, so the archeopyle is undoubtedly precingular.
Location and stratigraphy: Wuqia County Basebulak; Wulagen fm.