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Hystrichosphaera pachydermum
Hystrichosphaera pachydermum, Vieira, M. et al., 2018, p. 189
Holotype: Vieira, M. et al., 2018, Plate 4, figure 7
Type locality: southern part of the Ormen Lange field (Norway) over the Danian-aged reservoir
Local stratigraphical range: Danian (Early Paleocene)
Original description: Vieira, M. et al., 2018:
Diagnosis:
Proximochorate to skolochorate cyst with spherical to subspherical, smooth to finely granular central body, wall composed of two layers, endophragm extremely thick (up to 5.5 µm), periphragm thin, smooth and slightly granulate.
Processes: The latter bears thin, well-developed and very long intratabular processes. These processes are tubiform, open distally with serrate
circular margins. Length and width of processes are extremely variable (up to 51 µm in length) and also vary in number between 24 and 28. Their length is usually slightly greater than the diameter of the central body. In several samples, some of the processes are either broken or detached from the cysts.
Archaeopyle: Apical, usually present, with the operculum free.
Dimensions:
Holotype: Cyst body length 72 µm, width 59 µm (operculum attached); length 142 µm–width 144 µm (with processes), length of processes 53 µm.
20 specimens measured: Cyst diameter 52 (65) 72 µm, cyst with processes 135 (145) 158 µm, length of processes up to 44 (48) 55 µm,
breadth of processes 2 (3.5) 5 µm
Remarks:
Hystrichosphaeridium pachydermum sp. nov. was recorded in high numbers from 2997.37 m (core) to 3001.82 m (core).
Affinities/Comparison:
This species often possesses a thick and robust central body together with unusually long processes, which are characteristic of this species. These diagnostic features are used to differentiate this species from others within the genus.
Holotype: Vieira, M. et al., 2018, Plate 4, figure 7
Type locality: southern part of the Ormen Lange field (Norway) over the Danian-aged reservoir
Local stratigraphical range: Danian (Early Paleocene)
Original description: Vieira, M. et al., 2018:
Diagnosis:
Proximochorate to skolochorate cyst with spherical to subspherical, smooth to finely granular central body, wall composed of two layers, endophragm extremely thick (up to 5.5 µm), periphragm thin, smooth and slightly granulate.
Processes: The latter bears thin, well-developed and very long intratabular processes. These processes are tubiform, open distally with serrate
circular margins. Length and width of processes are extremely variable (up to 51 µm in length) and also vary in number between 24 and 28. Their length is usually slightly greater than the diameter of the central body. In several samples, some of the processes are either broken or detached from the cysts.
Archaeopyle: Apical, usually present, with the operculum free.
Dimensions:
Holotype: Cyst body length 72 µm, width 59 µm (operculum attached); length 142 µm–width 144 µm (with processes), length of processes 53 µm.
20 specimens measured: Cyst diameter 52 (65) 72 µm, cyst with processes 135 (145) 158 µm, length of processes up to 44 (48) 55 µm,
breadth of processes 2 (3.5) 5 µm
Remarks:
Hystrichosphaeridium pachydermum sp. nov. was recorded in high numbers from 2997.37 m (core) to 3001.82 m (core).
Affinities/Comparison:
This species often possesses a thick and robust central body together with unusually long processes, which are characteristic of this species. These diagnostic features are used to differentiate this species from others within the genus.