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Glaphyrocysta vicina
Glaphyrocysta? vicina (Eaton, 1976) Stover and Evitt, 1978
Originally Cyclonephelium, subsequently (and now) Glaphyrocysta?. At the time of the transfer, Stover and Evitt, 1978, considered this to be a provisionally accepted species of Glaphyrocysta.
Holotype: Eaton, 1976, pl.8, fig.4; text-fig.13; Bujak et al., 1980, pl.9, figs.9,12; Fauconnier and Masure, 2004, pl.34, figs.11–14.
Locus typicus: Whitecliff Bay, Isle of Wight, England
Stratum typicum: Early-Late Eocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Glaphyrocysta? vicina (Eaton, 1976) Stover and Evitt, 1978. According to Eaton (1976), this species has finely granular periphragm which is separated from, but remains close to the endophragm over the peripheral zone of the cyst body. The separated periphragm is wrinkled and folded. Fenestrations may be developed adjacent to or sometimes away from the line of separation. The presence of the marginal pericoel distinguishes this species from others of the genus Glaphyrocysta. There is some similarity to Membranophoridium aspinatum but in G.vicina the separated periphragm usually lies closer to the endophragm. Size: loisthocyst length 45 x 50 to 68 x 77 µm. Height of pericoel up to 18 µm.
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Original diagnosis: Eaton, 1976, p. 261: Cyclonephelium vicinum
Cyst body dorsoventrally flattened with a circular or subcircular outline. The finely granular periphragm is separated from, but remains close to, the endophragm over the peripheral zone of the cyst body. The separated periphragm is wrinkled and folded. Fenestrations may be developed adjacent to, or sometimes away from, the line of separation. Archaeopyle apical, tetratabular.
Dimensions: Holotype: cyst body (without operculum) 54x67 µm; height of pericoel up to 14 µm. Observed range: cyst body (without operculum) 45x50 µm to 68x77 µm; height of pericoel up to 18 µm. (n = 18).
Affinities:
Eaton, 1976, p. 261: Cyclonephelium vicinum
The development of several fenestrations in the separated periphragm adjacent to the line of separation may give the appearance of a row of distally united membranous processes. The presence of a marginal pericoel distinguishes C. vicinum from all described species of Cyclonephelium. In overall form the specimens here described are similar to those recorded from the Middle Oligocene of north Germany by Gocht (1969) as Chiropteridium aspinatum (Gerlach) Brosius 1963, but in C. vicinum the separated periphragm usually lies closer to the endophragm. The assignment of Gocht's specimens to Chiropteridium seems questionable, and it is possible that C. vicinum may be an evolutionary predecessor of the forms described by Gocht. This problem cannot be resolved until forms of intermediate age have been studied.
Originally Cyclonephelium, subsequently (and now) Glaphyrocysta?. At the time of the transfer, Stover and Evitt, 1978, considered this to be a provisionally accepted species of Glaphyrocysta.
Holotype: Eaton, 1976, pl.8, fig.4; text-fig.13; Bujak et al., 1980, pl.9, figs.9,12; Fauconnier and Masure, 2004, pl.34, figs.11–14.
Locus typicus: Whitecliff Bay, Isle of Wight, England
Stratum typicum: Early-Late Eocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Glaphyrocysta? vicina (Eaton, 1976) Stover and Evitt, 1978. According to Eaton (1976), this species has finely granular periphragm which is separated from, but remains close to the endophragm over the peripheral zone of the cyst body. The separated periphragm is wrinkled and folded. Fenestrations may be developed adjacent to or sometimes away from the line of separation. The presence of the marginal pericoel distinguishes this species from others of the genus Glaphyrocysta. There is some similarity to Membranophoridium aspinatum but in G.vicina the separated periphragm usually lies closer to the endophragm. Size: loisthocyst length 45 x 50 to 68 x 77 µm. Height of pericoel up to 18 µm.
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Original diagnosis: Eaton, 1976, p. 261: Cyclonephelium vicinum
Cyst body dorsoventrally flattened with a circular or subcircular outline. The finely granular periphragm is separated from, but remains close to, the endophragm over the peripheral zone of the cyst body. The separated periphragm is wrinkled and folded. Fenestrations may be developed adjacent to, or sometimes away from, the line of separation. Archaeopyle apical, tetratabular.
Dimensions: Holotype: cyst body (without operculum) 54x67 µm; height of pericoel up to 14 µm. Observed range: cyst body (without operculum) 45x50 µm to 68x77 µm; height of pericoel up to 18 µm. (n = 18).
Affinities:
Eaton, 1976, p. 261: Cyclonephelium vicinum
The development of several fenestrations in the separated periphragm adjacent to the line of separation may give the appearance of a row of distally united membranous processes. The presence of a marginal pericoel distinguishes C. vicinum from all described species of Cyclonephelium. In overall form the specimens here described are similar to those recorded from the Middle Oligocene of north Germany by Gocht (1969) as Chiropteridium aspinatum (Gerlach) Brosius 1963, but in C. vicinum the separated periphragm usually lies closer to the endophragm. The assignment of Gocht's specimens to Chiropteridium seems questionable, and it is possible that C. vicinum may be an evolutionary predecessor of the forms described by Gocht. This problem cannot be resolved until forms of intermediate age have been studied.