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Cribroperidinium erymnoseptum
Cribroperidinium erymnoseptum Bailey, 1993
Holotype: Bailey, 1993, pl.2, figs.1-2
Locus typicus: BP Norwegian Well 2/1-8 at 3937.40m (core, Farsund Formation), North Sea
Stratum typicum: Kimmeridgian
Original diagnosis: Bailey, 1993, p.220
A species of Cribroperidinium with a subspherical to ovoidal body, surmounted by a small apical horn. Sexiform Gonyaulacoid paratabulation is expressed by variably developed parasutural features of generally low relief. These comprise an assortment of irregular arched/ trabeculate crests, spines, and columns, which may be capitate, echinate and bifurcate distally. Similar features are developed as growth lines on intratabular areas. Archaeopyle precingular, type P (3"). Size range. 50 Ám-80 Ám overall length (holotype 78 Ám x 57 Ám.
Remarks. The hypocyst and epicyst are of more or less equal proportions, separated by a slightly laevorotary paracingulum. The short apical horn is solid and may be simple, spinose or capitate. The parasutural ornament is variably developed, from rows of spines or columns, aligned along paraplate boundaries to complex fence-like crests, comprising arched and trabeculate elements. The crests are generally 2-4 Ám in height, but can be over 5 Ám on the hypocysts of some strongly ornamented specimens.
Affinities:
Bailey, 1993, p.220: Cribroperidiniurm eryrmnoserpum differs from other species of the genus by the characteristic parasutural features and smooth autophragm. Some of the more ornamented forms are similar to Exiguisphaera phragma Duxbury 1980, but do not have 2P archaeopyles and have coarser, more robust parasutural ornament.
Holotype: Bailey, 1993, pl.2, figs.1-2
Locus typicus: BP Norwegian Well 2/1-8 at 3937.40m (core, Farsund Formation), North Sea
Stratum typicum: Kimmeridgian
Original diagnosis: Bailey, 1993, p.220
A species of Cribroperidinium with a subspherical to ovoidal body, surmounted by a small apical horn. Sexiform Gonyaulacoid paratabulation is expressed by variably developed parasutural features of generally low relief. These comprise an assortment of irregular arched/ trabeculate crests, spines, and columns, which may be capitate, echinate and bifurcate distally. Similar features are developed as growth lines on intratabular areas. Archaeopyle precingular, type P (3"). Size range. 50 Ám-80 Ám overall length (holotype 78 Ám x 57 Ám.
Remarks. The hypocyst and epicyst are of more or less equal proportions, separated by a slightly laevorotary paracingulum. The short apical horn is solid and may be simple, spinose or capitate. The parasutural ornament is variably developed, from rows of spines or columns, aligned along paraplate boundaries to complex fence-like crests, comprising arched and trabeculate elements. The crests are generally 2-4 Ám in height, but can be over 5 Ám on the hypocysts of some strongly ornamented specimens.
Affinities:
Bailey, 1993, p.220: Cribroperidiniurm eryrmnoserpum differs from other species of the genus by the characteristic parasutural features and smooth autophragm. Some of the more ornamented forms are similar to Exiguisphaera phragma Duxbury 1980, but do not have 2P archaeopyles and have coarser, more robust parasutural ornament.