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Rigaudella filamentosa
Rigaudella filamentosa (Cookson and Eisenack, 1958) Below, 1982
Originally Cannosphaeropsis, subsequently Adnatosphaeridium, thirdly (and now) Rigaudella.
Tax. sr. synonym of Cannosphaeropsis (ultimately Rigaudella) perforata Alberti, 1961, according to Stancliffe and Sarjeant, 1990.
Holotype: Cookson and Eisenack, 1958, pl.7, fig.9
Locus typicus: Dingo Siltstone, Carnavon Basin, W Australia
Stratum typicum: Middle-Late Jurassic
Translation Below, 1982: LPP
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP Rigaudella filamentosa (Cookson and Eisenack, 1958) Below, 1982b. Rigaudella filamentosa has a varying number of thin, solid processes which branch distally, sometimes in a fan-shaped manner, to form by their coalescence an open or sometimes dense enveloping network. The processes are more uniform in size than in Rigaudella aemula and never possess the hollow extremities of the latter. Below (1982), in his restudy of the species, noted trabeculae which do not always form complete rings and variability in process morphology as illustrated by the two paratypes. The division of the processes can start anywhere along their length and the resulting complexity of fenestration is variable. Below believed R. filamentosa to be a taxonomic senior synonym of R. perforata. Holotype overall size is 124 µm, size of body 48 µm.
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Original description: Cookson and Eisenack, 1958, p.47
Shell approximately spherical, provided with a varying number of thin, solid processes which branch distally, sometimes in a fan-shaped manner, to form by their coalescence an open or sometimes dense enveloping network.
Dimensions: holotype - overall diameter 124 µm, shell 48 µm.
Supplemental description: Below, 1982, p.149
Remark: The species is characterized by its very delicate processes. The basal branch of the process widens in the distal third into a large, broad funnel. The wall of the funnel is very coarsely fenestrate, so that the distal margin of the funnel is supported just by thin strings. The paratype depicted by Cookson and Eisenack 1958 (pl.7, fig.8) shows a clearly different expression of the processes. They are thin and not branched until the very distal end, where they split almost directly into the trabeculae, which interconnect the processes. This specimen rarely shows the distally funnel-shaped development of the processes.
Affinities:
Cookson and Eisenack 1958, p.47: Cannosphaeropsis filamentosa.
C. filamentosa is distinct from C. aemula in that the processes supporting the enveloping network are more uniform in size and never possess the hollow extremities of that species.
Originally Cannosphaeropsis, subsequently Adnatosphaeridium, thirdly (and now) Rigaudella.
Tax. sr. synonym of Cannosphaeropsis (ultimately Rigaudella) perforata Alberti, 1961, according to Stancliffe and Sarjeant, 1990.
Holotype: Cookson and Eisenack, 1958, pl.7, fig.9
Locus typicus: Dingo Siltstone, Carnavon Basin, W Australia
Stratum typicum: Middle-Late Jurassic
Translation Below, 1982: LPP
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP Rigaudella filamentosa (Cookson and Eisenack, 1958) Below, 1982b. Rigaudella filamentosa has a varying number of thin, solid processes which branch distally, sometimes in a fan-shaped manner, to form by their coalescence an open or sometimes dense enveloping network. The processes are more uniform in size than in Rigaudella aemula and never possess the hollow extremities of the latter. Below (1982), in his restudy of the species, noted trabeculae which do not always form complete rings and variability in process morphology as illustrated by the two paratypes. The division of the processes can start anywhere along their length and the resulting complexity of fenestration is variable. Below believed R. filamentosa to be a taxonomic senior synonym of R. perforata. Holotype overall size is 124 µm, size of body 48 µm.
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Original description: Cookson and Eisenack, 1958, p.47
Shell approximately spherical, provided with a varying number of thin, solid processes which branch distally, sometimes in a fan-shaped manner, to form by their coalescence an open or sometimes dense enveloping network.
Dimensions: holotype - overall diameter 124 µm, shell 48 µm.
Supplemental description: Below, 1982, p.149
Remark: The species is characterized by its very delicate processes. The basal branch of the process widens in the distal third into a large, broad funnel. The wall of the funnel is very coarsely fenestrate, so that the distal margin of the funnel is supported just by thin strings. The paratype depicted by Cookson and Eisenack 1958 (pl.7, fig.8) shows a clearly different expression of the processes. They are thin and not branched until the very distal end, where they split almost directly into the trabeculae, which interconnect the processes. This specimen rarely shows the distally funnel-shaped development of the processes.
Affinities:
Cookson and Eisenack 1958, p.47: Cannosphaeropsis filamentosa.
C. filamentosa is distinct from C. aemula in that the processes supporting the enveloping network are more uniform in size and never possess the hollow extremities of that species.