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Pyramidinium annulatum
Pyramidinium annulatum Razumk. Russ. Geol. Geophys., 66(8): 967. Jun 2025
- Name
- Pyramidinium annulatum
- Rank
- Species
- Generic Name
- [Genus] Pyramidinium
- Authors (Pub.)
- Razumkova E. S.
- Publication
- Two new genera and species of acritarchs from the Albian–Cenomanian of Southwest Western Siberia [2025/6]
- Journal
- Russian Geology and Geophysics
- Volume
- 66
- Issue
- 8
- Page number
- 967
- Year
- 2025
- Fossil Status
- cysts
- Stratigraphy
- Cenomanian
- Strat. comment
- Uvat Formation
- Location
- borehole B3, sample 690; depth 690–700 m, southwest Western Siberia, Khanty-Mansi Autonomous district, Russian Federation
- Paleoregion
- Eurasia (W Siberia)
Data for Holotypus
- Repository
- Karpinsky Russian Geological Research Institute, (VSEGEI), St.-Petersburg, Russian Federation
- Repository Number
- preparation No. K26-28/3-690; England Finder coordinates V41/2
Data for Paratypus
- Repository
- Karpinsky Russian Geological Research Institute, (VSEGEI), St.-Petersburg, Russian Federation
- Repository Number
- preparation No. 28/4-670; England Finder coordinates W44/1, 2
- Diagnosis
- A smooth vesicle in the shape of a truncated pyramid. The base (bottom wall) is square with rounded corners, the opposite surface (upper wall) is round with a thickening along the contour and pylome of unclear shape in the center; four ribs form four side walls and extend from the upper wall to the corners of the bottom wall. In plan, the vesicle has a square outline with
rounded corners and a ring in the center, inside of which there is an indistinct pylome with jagged edges. The width of the bottom wall is 18–35 μm, the length of the rib from the bottom to the upper wall is 18–22 μm.
