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Cleistosphaeridium flexuosum
Cleistosphaeridium flexuosum, Davey et al., 1966; emend. Sarkar and Singh, 1988
NOW Downiesphaeridium. Originally Cleistosphaeridium?, subsequently Polysphaeridium?, thirdly Cleistosphaeridium, fourthly (and now) Downiesphaeridium.
Davey et al., 1966, questionably included this species in Cleistosphaeridium. Sarkar and Singh, 1988, included the species in Cleistosphaeridium without question.
Holotype: Davey et al., 1966, pl.2, fig.5; Fauconnier and Masure, 2004, pl.23, fig.8.
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Cenomanian
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Original description: [Davey et al., 1966, p.169]:
Diagnosis:
Central body subsphaerical to elongate, bearing numerous, broadly acuminate, processes. All processes of approximately same length, slightly fibrous and always flexuous.
Description:
The most distinctive feature of ?C. flexuosum is the flexuous nature of the broad fibrous processes. The nature of the surface of the central body is difficult to determine and the presence of an archaeopyle has not been recorded.
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Emended description:
Sarkar and Singh, 1988, p. 39:
Diagnosis:
Central body subspherical to elongate. Body wall made up of autophragm only which is granulose in ornamentation. Numerous nontabular processes are present all over the body surface. The processes are hollow, unbranched and distally closed with a acuminate end. All processes are of almost same sizes and shape fibrous and flexuosus in nature.
The archaeopyle is apical in position.
Paratabulation is not very clear due to the clustering of processes.
Dimensions:
Observed range: Size of the central body 35 x 30 µm to 65 x 40 µm; length of the processes 8 µm to 20 µm.
Affinities:
The nature of the processes easily differentiate ?C. flexuosum from all other previously described species.
NOW Downiesphaeridium. Originally Cleistosphaeridium?, subsequently Polysphaeridium?, thirdly Cleistosphaeridium, fourthly (and now) Downiesphaeridium.
Davey et al., 1966, questionably included this species in Cleistosphaeridium. Sarkar and Singh, 1988, included the species in Cleistosphaeridium without question.
Holotype: Davey et al., 1966, pl.2, fig.5; Fauconnier and Masure, 2004, pl.23, fig.8.
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Cenomanian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey et al., 1966, p.169]:
Diagnosis:
Central body subsphaerical to elongate, bearing numerous, broadly acuminate, processes. All processes of approximately same length, slightly fibrous and always flexuous.
Description:
The most distinctive feature of ?C. flexuosum is the flexuous nature of the broad fibrous processes. The nature of the surface of the central body is difficult to determine and the presence of an archaeopyle has not been recorded.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Sarkar and Singh, 1988, p. 39:
Diagnosis:
Central body subspherical to elongate. Body wall made up of autophragm only which is granulose in ornamentation. Numerous nontabular processes are present all over the body surface. The processes are hollow, unbranched and distally closed with a acuminate end. All processes are of almost same sizes and shape fibrous and flexuosus in nature.
The archaeopyle is apical in position.
Paratabulation is not very clear due to the clustering of processes.
Dimensions:
Observed range: Size of the central body 35 x 30 µm to 65 x 40 µm; length of the processes 8 µm to 20 µm.
Affinities:
The nature of the processes easily differentiate ?C. flexuosum from all other previously described species.