Back
Cribroperidinium globosum
Cribroperidinium? globosum (Brideaux, 1971) Helenes, 1984
Originally Gonyaulacysta, subsequently Millioudodinium?, thirdly (and now) Cribroperidinium?.
At the time of the transfer, Helenes, 1984, considered this to be a provisionally assigned species of Cribroperidinium.
Holotype: Brideaux, 1971, pl.23, figs.37-38, fext-fig.7g-h; Jan du Chêne et al., 1986, pl.28, figs.10-11
Locus typicus: Alberta, Canada
Stratum typicum: Middle-Late Albian
Original description (Holotype): Brideaux, 1971, p.81: Gonyaualcysta globosa
Length, 115 Ám; width 90 Ám; apical horn length 18 Ám. Main cyst nearly globular with short apical horn; antapex rounded. Epitract including apical horn longer than hypotract. Cingulum slightly helicoid, sinistral, the dorsal course somewhat zig-zag. Sulcus widest antapically, slightly sinuous, narrowing and extending onto the epitract, terminated apically by plate 1" and antapically by plate 1"""". Low ledges outline tabulation, ledges somewhat knobby. Tabulation scheme determined as: 4", 6", 0c, 6""", 1p. 1"""". Several plates show intertabular mimicry of plate boundaries. Holotype specimen intact, showing no archeopyle.
Description: Brideaux, 1971, p.81: Gonyaualcysta globosa
Dinoflagellate cyst; globular to rounded-pentagonal outline. Cingulum, with faintly zig-zag outline, slightly helicoid, and sinistral; sulcus extending partially onto the epitract and meeting plate 1", widening slightly antapically to meet plate 1"""". Epitract, not including horn, and hypotract nearly equal in length. Distinct apical horn, variable in length and shape, often incompletely preserved. Reflected tabulation of 4", ?1 a, 6", 6""", 1p, 1"""" demarcated by low, narrow sutures; occasional specimens have secondary ridges which are intratabular in position and parallel the plate boundaries. Ridges outlining the girdle are somewhat higher and more robust. Archeopyle precingular; operculum formed of plate 3", roughly trapezoidal in shape.
Dimensions: Length on 27 measured specimens, 74-115 Ám; width on 26 measured specimens, 64-92 Ám; apical horn length on 25 measured specimens, 10-31 Ám.
Affinities:
Brideaux, 1971, p.81: Gonyaualcysta globosa
Gonyaulacysta globosa is distinguished from other species of this genus by the combination of its shape and tabulation pattern. Gonyaulacysta palla Sarjeant, 1966, p.113; pl.13, figs.3-4; text-fig. 21, is similar in shape and has an apical horn somewhat like some specimens of G. globosa but differs in plating, possessing 7""" plates and 6 cingular plates as well as in other details.
Originally Gonyaulacysta, subsequently Millioudodinium?, thirdly (and now) Cribroperidinium?.
At the time of the transfer, Helenes, 1984, considered this to be a provisionally assigned species of Cribroperidinium.
Holotype: Brideaux, 1971, pl.23, figs.37-38, fext-fig.7g-h; Jan du Chêne et al., 1986, pl.28, figs.10-11
Locus typicus: Alberta, Canada
Stratum typicum: Middle-Late Albian
Original description (Holotype): Brideaux, 1971, p.81: Gonyaualcysta globosa
Length, 115 Ám; width 90 Ám; apical horn length 18 Ám. Main cyst nearly globular with short apical horn; antapex rounded. Epitract including apical horn longer than hypotract. Cingulum slightly helicoid, sinistral, the dorsal course somewhat zig-zag. Sulcus widest antapically, slightly sinuous, narrowing and extending onto the epitract, terminated apically by plate 1" and antapically by plate 1"""". Low ledges outline tabulation, ledges somewhat knobby. Tabulation scheme determined as: 4", 6", 0c, 6""", 1p. 1"""". Several plates show intertabular mimicry of plate boundaries. Holotype specimen intact, showing no archeopyle.
Description: Brideaux, 1971, p.81: Gonyaualcysta globosa
Dinoflagellate cyst; globular to rounded-pentagonal outline. Cingulum, with faintly zig-zag outline, slightly helicoid, and sinistral; sulcus extending partially onto the epitract and meeting plate 1", widening slightly antapically to meet plate 1"""". Epitract, not including horn, and hypotract nearly equal in length. Distinct apical horn, variable in length and shape, often incompletely preserved. Reflected tabulation of 4", ?1 a, 6", 6""", 1p, 1"""" demarcated by low, narrow sutures; occasional specimens have secondary ridges which are intratabular in position and parallel the plate boundaries. Ridges outlining the girdle are somewhat higher and more robust. Archeopyle precingular; operculum formed of plate 3", roughly trapezoidal in shape.
Dimensions: Length on 27 measured specimens, 74-115 Ám; width on 26 measured specimens, 64-92 Ám; apical horn length on 25 measured specimens, 10-31 Ám.
Affinities:
Brideaux, 1971, p.81: Gonyaualcysta globosa
Gonyaulacysta globosa is distinguished from other species of this genus by the combination of its shape and tabulation pattern. Gonyaulacysta palla Sarjeant, 1966, p.113; pl.13, figs.3-4; text-fig. 21, is similar in shape and has an apical horn somewhat like some specimens of G. globosa but differs in plating, possessing 7""" plates and 6 cingular plates as well as in other details.