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Gonyaulacysta systremmata
Gonyaulacysta systremmata Gitmez and Sarjeant, 1972
Originally Gonyaulacysta, subsequently Cribroperidinium, thirdly Millioudodinium, fourthly Cribroperidinium?, fifthly Acanthaulax.
Taxonomic senior synonym: Gonyaulacysta (as and now Cribroperidinium) globata, according to Poulsen (1996, p.72).
Holotype: Gitmezand Sarjeant, 1972, pl.5, figs.7-8; Jan du Chene et al., 1986, pl.29, figs.4-7
Paratype: Gitmez and Sarjeant, 1972
Locus typicus: Boulonnais, France
Stratum typicum: Early Kimmeridgian
Original diagnosis: Gitmez and Sarjeant, 1972, p.204-205
Thick-walled shell, almost spherical, with a moderately long apical horn. Tabulation 4", 1a, 6"", 6-7c, 7""", 1p, 1pv, 1"""". The plate boundaries are demarcated by delicate crests of variable height. The cingulum is helicoid, laevorotatory; the sulcus is short and broadens posteriorly. The surface is densely granular. A precingular archeopyle, formed by loss of plate 3", is generally developed.
Dimensions: Holotype: overall length 68 Ám, breath 62 Ám, horn length 8 Ám, height of the crests 4-5 Ám. Range of the observed specimens: overall length 66-78 Ám, breadth 60-65 Ám, horn length 7-16 Ám; measured spccimens 5 in number.
Original description: Gitmez and Sarjeant, 1972, p.205
The helicoid, laevorotatory cingulum divides the cyst unequally. The epitract is somewhat longer than the hypotract; both are more or less domeshaped. The number of the cingular plates is hesitantly mentioned, because the character of the small plate beside 6c is doubtful; it may be either a small cingular plate or a short sulcal plate.
The apical plates make up the apex, plate 1" occupying the anterior prolongation of the sulcus. Plates 2" and 3" are small, plate 4" is almost as large as plate 1". The single, small anterior intercalary plate is placed between the plates 4" and 6"". The precingular plates are generally large, plate 6" being of reduced size because of the presence of intercalary plate 1a.
The postcingular plates are of variable size and shape: plate 1""" is very small; plate 2""" is also reduced and does not have a boundary with the antapical plate. Plates 3""", 4""", 5""" and 6""" are relatively large; plate 7""" is in contrast reduced, having nearly the same size as plate 2""". The quite broad intercalary plate, 1pv separates the sulcus from the single antapical plate 1"""".
Originally Gonyaulacysta, subsequently Cribroperidinium, thirdly Millioudodinium, fourthly Cribroperidinium?, fifthly Acanthaulax.
Taxonomic senior synonym: Gonyaulacysta (as and now Cribroperidinium) globata, according to Poulsen (1996, p.72).
Holotype: Gitmezand Sarjeant, 1972, pl.5, figs.7-8; Jan du Chene et al., 1986, pl.29, figs.4-7
Paratype: Gitmez and Sarjeant, 1972
Locus typicus: Boulonnais, France
Stratum typicum: Early Kimmeridgian
Original diagnosis: Gitmez and Sarjeant, 1972, p.204-205
Thick-walled shell, almost spherical, with a moderately long apical horn. Tabulation 4", 1a, 6"", 6-7c, 7""", 1p, 1pv, 1"""". The plate boundaries are demarcated by delicate crests of variable height. The cingulum is helicoid, laevorotatory; the sulcus is short and broadens posteriorly. The surface is densely granular. A precingular archeopyle, formed by loss of plate 3", is generally developed.
Dimensions: Holotype: overall length 68 Ám, breath 62 Ám, horn length 8 Ám, height of the crests 4-5 Ám. Range of the observed specimens: overall length 66-78 Ám, breadth 60-65 Ám, horn length 7-16 Ám; measured spccimens 5 in number.
Original description: Gitmez and Sarjeant, 1972, p.205
The helicoid, laevorotatory cingulum divides the cyst unequally. The epitract is somewhat longer than the hypotract; both are more or less domeshaped. The number of the cingular plates is hesitantly mentioned, because the character of the small plate beside 6c is doubtful; it may be either a small cingular plate or a short sulcal plate.
The apical plates make up the apex, plate 1" occupying the anterior prolongation of the sulcus. Plates 2" and 3" are small, plate 4" is almost as large as plate 1". The single, small anterior intercalary plate is placed between the plates 4" and 6"". The precingular plates are generally large, plate 6" being of reduced size because of the presence of intercalary plate 1a.
The postcingular plates are of variable size and shape: plate 1""" is very small; plate 2""" is also reduced and does not have a boundary with the antapical plate. Plates 3""", 4""", 5""" and 6""" are relatively large; plate 7""" is in contrast reduced, having nearly the same size as plate 2""". The quite broad intercalary plate, 1pv separates the sulcus from the single antapical plate 1"""".