Back
Pervosphaeridium multispinum
From Fensome et al., 2019:
Pervosphaeridium multispinum Slimani, 1994, p.81–82, pl.12, figs.10–14. Holotype: Slimani, 1994, pl.12, figs.10–12. Age: late Campanian–Danian.
---------------------------------------------------------------------------------------------------
Original description (Slimani, 1994):
Pervosphaeridium multispinum sp. nov. (PI.12, Fig.10-14)
Name derivation: Latin: multus, numerous; spina, thorn; reference to the numerous processes.
Horizon: Halembaye slab 40, preparation 2, EF coord. R36/4.
Parasite: Halembaye slab 57, preparation 1, EF coord. Z56.
Type locality: Halembaye slab 40.
Type horizon: Upper Maastrichtian (Vijlen Member).
Diagnosis: Small chorate to proximochorate cyst; the central body is spheroidal, subspheroidal to ovoidal. It is fibrous and bears numerous simple non-tabular processes which are quite wide, hollow and more or less fibrous in their proximal part and which thin distally where they are generally solid. They terminate distally in a capitate to buccinate end. An apical process, often bifurcated, is more or less distinct. The archaeopyle is precingulate of type 2P, the operculum consists of two free pieces which are sometimes recovered inside the cyst.
Dimensions: Holotype: Maximum central body diameter: 30 µm, total diameter: 50 µm. Variations: Maximum central body diameter: 28-40 µm, total diameter: 40-60 µm. Number of specimens measured: 32.
Material: > 400 specimens.
Description: The wall is 1 to 1.5 µm thick. It is formed by a smooth endophragm and a fibrous periphragm that are joined between the processes. The processes are uniform, between 1/5 and 1/3 of the diameter of the central body and regularly distributed; their distal end is generally solid which is abruptly flared into a small flattened swelling at the top. Proximally, these processes are more fibrous and only occasionally merge. The length of the processes in this species is uniform in the same specimen but varies intraspecifically. The periphragm is more fibrous in some individuals than in others. The apical process is a little wider but of the same length as the normal processes and often bifurcates into two small processes of the same type as the other processes; it surmounts a small apical bump more or less pronounced and of size of about 2 µm in the holotype.
Comparisons: Pervosphaeridium multispinum sp. nov. is reminiscent of Kiokansium polypes (COOKSON and EISENACK . 1962b) BELOW ( 1982c) by the shape of the distal end of the processes but it differs by its fibrous and constantly hollow processes proximally and by the presence of a fibrous periphragm. It closely resembles the specimens from the Maastrichtian of Hemmoor (Germany) figured under the name Lingulodinium machaerophorum (DEFLANDRE and COOKSON , 1955) WALL ( 1967), by MARHEINECKE ( 1992: pl. 10, fig. 1 -3 ), but these specimens present an archaeopyle combining the apical and precingular paraplates according to the latter author. Kiokansium sp. figured by KIKSCII (1991: pl. 21, fig. 1) could be close to the species studied, but the nature of the processes and the presence or absence of a fibrous periphragm are unknown. Pervosphaeridium pseudhystrichodinium (DEFLANDRE, 1937b) YUN (1981) has a larger size and possesses simple or occasionally bifurcated processes that terminate distally in a truncated or forked tip. The specimen from the upper Maastrichtian of NE Belgium, named Potysphaeridium sp. cf. P. sp. in FOUCHER and TAUGOURDEA U (1975), by SCHUMACKER-LAMBRY in STREEL et al. (1977: fig. 25, pl. 3, fig. 21) presents the same morphological characteristics as our species, its archaeology is unfortunately not clearly visible.
Locality: Beutenaken: samples 2 to 18, Halembaye: samples 12 to 87; upper Campanian - Maastrichtian upper. (B. mucronata zone - B. junior zone). Turnhout: -978 to -722.40 m, upper Campanian. - Danien.
Pervosphaeridium multispinum Slimani, 1994, p.81–82, pl.12, figs.10–14. Holotype: Slimani, 1994, pl.12, figs.10–12. Age: late Campanian–Danian.
---------------------------------------------------------------------------------------------------
Original description (Slimani, 1994):
Pervosphaeridium multispinum sp. nov. (PI.12, Fig.10-14)
Name derivation: Latin: multus, numerous; spina, thorn; reference to the numerous processes.
Horizon: Halembaye slab 40, preparation 2, EF coord. R36/4.
Parasite: Halembaye slab 57, preparation 1, EF coord. Z56.
Type locality: Halembaye slab 40.
Type horizon: Upper Maastrichtian (Vijlen Member).
Diagnosis: Small chorate to proximochorate cyst; the central body is spheroidal, subspheroidal to ovoidal. It is fibrous and bears numerous simple non-tabular processes which are quite wide, hollow and more or less fibrous in their proximal part and which thin distally where they are generally solid. They terminate distally in a capitate to buccinate end. An apical process, often bifurcated, is more or less distinct. The archaeopyle is precingulate of type 2P, the operculum consists of two free pieces which are sometimes recovered inside the cyst.
Dimensions: Holotype: Maximum central body diameter: 30 µm, total diameter: 50 µm. Variations: Maximum central body diameter: 28-40 µm, total diameter: 40-60 µm. Number of specimens measured: 32.
Material: > 400 specimens.
Description: The wall is 1 to 1.5 µm thick. It is formed by a smooth endophragm and a fibrous periphragm that are joined between the processes. The processes are uniform, between 1/5 and 1/3 of the diameter of the central body and regularly distributed; their distal end is generally solid which is abruptly flared into a small flattened swelling at the top. Proximally, these processes are more fibrous and only occasionally merge. The length of the processes in this species is uniform in the same specimen but varies intraspecifically. The periphragm is more fibrous in some individuals than in others. The apical process is a little wider but of the same length as the normal processes and often bifurcates into two small processes of the same type as the other processes; it surmounts a small apical bump more or less pronounced and of size of about 2 µm in the holotype.
Comparisons: Pervosphaeridium multispinum sp. nov. is reminiscent of Kiokansium polypes (COOKSON and EISENACK . 1962b) BELOW ( 1982c) by the shape of the distal end of the processes but it differs by its fibrous and constantly hollow processes proximally and by the presence of a fibrous periphragm. It closely resembles the specimens from the Maastrichtian of Hemmoor (Germany) figured under the name Lingulodinium machaerophorum (DEFLANDRE and COOKSON , 1955) WALL ( 1967), by MARHEINECKE ( 1992: pl. 10, fig. 1 -3 ), but these specimens present an archaeopyle combining the apical and precingular paraplates according to the latter author. Kiokansium sp. figured by KIKSCII (1991: pl. 21, fig. 1) could be close to the species studied, but the nature of the processes and the presence or absence of a fibrous periphragm are unknown. Pervosphaeridium pseudhystrichodinium (DEFLANDRE, 1937b) YUN (1981) has a larger size and possesses simple or occasionally bifurcated processes that terminate distally in a truncated or forked tip. The specimen from the upper Maastrichtian of NE Belgium, named Potysphaeridium sp. cf. P. sp. in FOUCHER and TAUGOURDEA U (1975), by SCHUMACKER-LAMBRY in STREEL et al. (1977: fig. 25, pl. 3, fig. 21) presents the same morphological characteristics as our species, its archaeology is unfortunately not clearly visible.
Locality: Beutenaken: samples 2 to 18, Halembaye: samples 12 to 87; upper Campanian - Maastrichtian upper. (B. mucronata zone - B. junior zone). Turnhout: -978 to -722.40 m, upper Campanian. - Danien.