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Cyclonephelium operculatum
From Fensome et al., 2019:
Cyclonephelium operculatum Yu Jingxian, 1982, p.252–253, pl.7, figs.20–22. Holotype: Yu Jingxian, 1982, pl.7, fig.21; Fensome et al., 2019a, fig.16A.
Questionable assignment: Fauconnier and Londeix in Fauconnier and Masure (2004, p.147) as a problematic species.
Age: Late Jurassic–Early Cretaceous.
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Description: Cysts circular or elliptical in outline, dorsoventrally compressed. Periphragm thin, about 0.5 µm thick. A ring of perforations along cyst periphery. Perforations circular or elliptical, 4 - 6 µm in diameter. Inner body subcircular. Surface granulate or finely reticulate. Apical archaeopyle.
Size: Cysts 44 - 50 µm long and 36 - 46 µm wide.
Comparison: The new species has some similarity to C. membraniphorum Cookson & Eisenack 1962 in the ring of perforations along the periphery of the cyst but is distinguished from it by the fact that it has small individuals, its perforations are circular or elliptical. and the inner body has granulate or reticulate ornamentation.
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Comments Fensome et al., 2019a:
Fauconnier & Londeix in Fauconnier & Masure (2004) considered this a problematic species. We agree, and hence concur that its assignment to Cyclonephelium is questionable. We recommend that use of this name be restricted to the type material.
Stratigraphical occurrence. Yu Jingxian (1982) described this species from the Upper Jurassic‒Lower Cretaceous of China.
Cyclonephelium operculatum Yu Jingxian, 1982, p.252–253, pl.7, figs.20–22. Holotype: Yu Jingxian, 1982, pl.7, fig.21; Fensome et al., 2019a, fig.16A.
Questionable assignment: Fauconnier and Londeix in Fauconnier and Masure (2004, p.147) as a problematic species.
Age: Late Jurassic–Early Cretaceous.
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Description: Cysts circular or elliptical in outline, dorsoventrally compressed. Periphragm thin, about 0.5 µm thick. A ring of perforations along cyst periphery. Perforations circular or elliptical, 4 - 6 µm in diameter. Inner body subcircular. Surface granulate or finely reticulate. Apical archaeopyle.
Size: Cysts 44 - 50 µm long and 36 - 46 µm wide.
Comparison: The new species has some similarity to C. membraniphorum Cookson & Eisenack 1962 in the ring of perforations along the periphery of the cyst but is distinguished from it by the fact that it has small individuals, its perforations are circular or elliptical. and the inner body has granulate or reticulate ornamentation.
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Comments Fensome et al., 2019a:
Fauconnier & Londeix in Fauconnier & Masure (2004) considered this a problematic species. We agree, and hence concur that its assignment to Cyclonephelium is questionable. We recommend that use of this name be restricted to the type material.
Stratigraphical occurrence. Yu Jingxian (1982) described this species from the Upper Jurassic‒Lower Cretaceous of China.