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Rhynchodiniopsis globata
Rhynchidiniopsis globata (Gitmez and Sarjeant, 1972) Sarjeant, 1982
Now Cribroperidinium. Originally Gonyaulacysta, subsequently Millioudodinium, thirdly Rhynchodiniopsis, fourthly (and now) Cribroperidinium.
Holotype: Gitmez and Sarjeant, 1972, pl.3, fig.1, text-fig.5A; Jan du Chêne et al., 1986, pl.29, fig.3
Paratype: Gitmez and Sarjeant, 1972
Locus typicus: Warlingham, Surrey, England
Stratum typicum: Middle-late Kimmeridgian
Original diagnosis: Gitmez and Sarjeant, 1972, p.195, 197: Gonyaulacysta globata
A proximate cyst, subsphaerical to broadly oval with a strong apical horn. The sutural crests are low, generally well defined, and reflect the tabulation 4", 1a, 6"" 6c, 6""", ?1p, 1"""". Cingulum moderately narrow, helicoid, laevorotatory, dividing the theca unequally, the epitract being longer than the hypotract. The sulcus is broad. The surface of the shell is densely granular. A precingular archaeopyle, formed by the loss of plate 3"", is developed in some instances.
Dimensions: Holotype: overall length 90 µm, breadth 68 µm, apical horn length 11 µm. Range: overall length 85-92 µm, breadth 62-75 µm, horn length11-12 µm.
Original description: Gitmez and Sarjeant, 1972, p.197: Gonyaulacysta globata
The cyst is globular, relatively thin-walled. Four apical plates combine to form the slender horn. Plate 1" is narrow and elongate, the other apical plates are approximately polygonal but with an apical prolongation. A single anterior intercalary plate is present and quite large, apical plate 4" and precingular plates 5"" and 6"" being correspondingly reduced. The four other precingular plates are large. The cingular plates are poorly defined, but appear to number six. The hypotract is dome-shaped, composed of large reflected plates, plate 4""" is the largest of all. Plate 1""" is greatly reduced; plates 5"""and 6""" are relatively small. The boundary between the plates 1p and 2""" was not confirmed. The single antapical plate, 1"""" is also large. The sulcus is narrow in its anterior portion, broadening to contact with the cingulum and thenceforward remaining of constant breadth in its posterior portion. It is relatively short and extends to the antapex. In one specimen only, a precingular archaeopyle was seen.
Now Cribroperidinium. Originally Gonyaulacysta, subsequently Millioudodinium, thirdly Rhynchodiniopsis, fourthly (and now) Cribroperidinium.
Holotype: Gitmez and Sarjeant, 1972, pl.3, fig.1, text-fig.5A; Jan du Chêne et al., 1986, pl.29, fig.3
Paratype: Gitmez and Sarjeant, 1972
Locus typicus: Warlingham, Surrey, England
Stratum typicum: Middle-late Kimmeridgian
Original diagnosis: Gitmez and Sarjeant, 1972, p.195, 197: Gonyaulacysta globata
A proximate cyst, subsphaerical to broadly oval with a strong apical horn. The sutural crests are low, generally well defined, and reflect the tabulation 4", 1a, 6"" 6c, 6""", ?1p, 1"""". Cingulum moderately narrow, helicoid, laevorotatory, dividing the theca unequally, the epitract being longer than the hypotract. The sulcus is broad. The surface of the shell is densely granular. A precingular archaeopyle, formed by the loss of plate 3"", is developed in some instances.
Dimensions: Holotype: overall length 90 µm, breadth 68 µm, apical horn length 11 µm. Range: overall length 85-92 µm, breadth 62-75 µm, horn length11-12 µm.
Original description: Gitmez and Sarjeant, 1972, p.197: Gonyaulacysta globata
The cyst is globular, relatively thin-walled. Four apical plates combine to form the slender horn. Plate 1" is narrow and elongate, the other apical plates are approximately polygonal but with an apical prolongation. A single anterior intercalary plate is present and quite large, apical plate 4" and precingular plates 5"" and 6"" being correspondingly reduced. The four other precingular plates are large. The cingular plates are poorly defined, but appear to number six. The hypotract is dome-shaped, composed of large reflected plates, plate 4""" is the largest of all. Plate 1""" is greatly reduced; plates 5"""and 6""" are relatively small. The boundary between the plates 1p and 2""" was not confirmed. The single antapical plate, 1"""" is also large. The sulcus is narrow in its anterior portion, broadening to contact with the cingulum and thenceforward remaining of constant breadth in its posterior portion. It is relatively short and extends to the antapex. In one specimen only, a precingular archaeopyle was seen.