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Apteodinium conicum
Apteodinium conicum, He Chengquan, 1991
Holotype: He Chengquan, 1991, pl.4, fig.6
Location and stratigraphy: Wuqia County Basebulak and Urukqiati, the middle member of the Kukebai fm; Simuhana, Upper member of the Kukebai fm.
Age: Cenomanian-Turonian
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Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The cyst is flat, the outline is more or less dome conical or gourd-shaped. The apex has a short apical horn, the dome is conical or papillary shape, 3-5μm long; Except the horn surface is usually smooth, there is no distinct boundaries between it and the granular body, it is transitional between each other, the base of the horn does not seem to be connected to the body. The antapex is round, lack of antapical horns.
Cingulum signs are weak, often difficult to see, and sometimes there is a knife-like horizontal wrinkle in the equatorial area or two parallel linear grooves.
No sulcus sign.
Thin cyst wall, the surface with clear particles, the blade-shaped wrinkle develops on the body. No obvious archeopyle. There might be a yellow-green core.
Dimensions:
The cyst length 45-57.5μm, width 36-47μm (measured 8); The holotype length 52.2μm, width 47μm, apical horn length 3 μm.
Affinities/Comparison:
This new species differs from Apteodinium granulatum in low apical horn, not sharp, body nearly conical etc; This new species is similar to A. reticdatum in appearance, but the latter’s surface is reticular; The body outline of A. maculatum is nearly round and different from the new species; In addition, the specimens of A. maculatum recorded in the mid-Albian, Horton river in Canada (Brideaux & Mcintyre, I975, p. 20, pl. 5, figs. I, 2) are very similar to the current new species, but larger in size and with a granular rod-reticular ornamentation on the surface. Finally, it is worth mentioning that if the current specimen does not have a dorsal-ventral view, then it is not easy to see the apical horn, and its outline is easily confused with the acritarch Granodiscus.
Holotype: He Chengquan, 1991, pl.4, fig.6
Location and stratigraphy: Wuqia County Basebulak and Urukqiati, the middle member of the Kukebai fm; Simuhana, Upper member of the Kukebai fm.
Age: Cenomanian-Turonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The cyst is flat, the outline is more or less dome conical or gourd-shaped. The apex has a short apical horn, the dome is conical or papillary shape, 3-5μm long; Except the horn surface is usually smooth, there is no distinct boundaries between it and the granular body, it is transitional between each other, the base of the horn does not seem to be connected to the body. The antapex is round, lack of antapical horns.
Cingulum signs are weak, often difficult to see, and sometimes there is a knife-like horizontal wrinkle in the equatorial area or two parallel linear grooves.
No sulcus sign.
Thin cyst wall, the surface with clear particles, the blade-shaped wrinkle develops on the body. No obvious archeopyle. There might be a yellow-green core.
Dimensions:
The cyst length 45-57.5μm, width 36-47μm (measured 8); The holotype length 52.2μm, width 47μm, apical horn length 3 μm.
Affinities/Comparison:
This new species differs from Apteodinium granulatum in low apical horn, not sharp, body nearly conical etc; This new species is similar to A. reticdatum in appearance, but the latter’s surface is reticular; The body outline of A. maculatum is nearly round and different from the new species; In addition, the specimens of A. maculatum recorded in the mid-Albian, Horton river in Canada (Brideaux & Mcintyre, I975, p. 20, pl. 5, figs. I, 2) are very similar to the current new species, but larger in size and with a granular rod-reticular ornamentation on the surface. Finally, it is worth mentioning that if the current specimen does not have a dorsal-ventral view, then it is not easy to see the apical horn, and its outline is easily confused with the acritarch Granodiscus.