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Gonyaulacysta extensa
Gonyaulacysta extensa Clarke and Verdier, 1967
Tax. jr. synonym of Psaligonyaulax deflandrei Sarjeant, 1966, according to Clarke et al., 1968.
Holotype: Clarke and Verdier, 1967, pl.4, figs.8-9
Locus typicus: Isle of Wight, England
Stratum typicum: Cenomanian
Original diagnosis: Clarke and Verdier, 1967, p.30
A species of Gonyaulacysta showing an antapical extension of the outer membrane to form a cavity between the inner body and the outer wall at the antapex.
Original description: Clarke and Verdier, 1967, p.30
Tabulation with 6 precingular plates and an archaeopyle formed by the loss of plate 3"; cingular plates present. Girdle strongly displaced more than two girdle widths. Ledges vary in height and are generally denticulate. Plates may possess verrucae whose nurmber and distribution is variable. An apical horn is present on which septa are visible and often a "lid" is observed at the extremity. An inner body is present which is only in contact with the outer wall around the girdle area.
Measurements:HolotypeRange
Overall length82 Ám60-84 Ám
Overall breadth50 Ám36-60 Ám
Length inner body46 Ám33-46 Ám
Breadth inner body44 Ám36-60 Ám
Width of girdle4 Ám3- 8 Ám
Height of ledges3 Ám1- 4 Ám
Height of apical horn10 Ám4-11 Ám
Affinities:
Clarke and Verdier, 1967, p.31: G. extensa differs from G. cassidata in the presence of a cavity situated antapically and formed by an extension of the outer wall. Therefore the inner body and the outer wall are not in contact in the antapical region. Such a feature is absent in G. cassidata where the inner body and outer wall are in contact at the antapex and where the antapical plate is bordered by a high denticulate ledge.
Tax. jr. synonym of Psaligonyaulax deflandrei Sarjeant, 1966, according to Clarke et al., 1968.
Holotype: Clarke and Verdier, 1967, pl.4, figs.8-9
Locus typicus: Isle of Wight, England
Stratum typicum: Cenomanian
Original diagnosis: Clarke and Verdier, 1967, p.30
A species of Gonyaulacysta showing an antapical extension of the outer membrane to form a cavity between the inner body and the outer wall at the antapex.
Original description: Clarke and Verdier, 1967, p.30
Tabulation with 6 precingular plates and an archaeopyle formed by the loss of plate 3"; cingular plates present. Girdle strongly displaced more than two girdle widths. Ledges vary in height and are generally denticulate. Plates may possess verrucae whose nurmber and distribution is variable. An apical horn is present on which septa are visible and often a "lid" is observed at the extremity. An inner body is present which is only in contact with the outer wall around the girdle area.
Measurements:HolotypeRange
Overall length82 Ám60-84 Ám
Overall breadth50 Ám36-60 Ám
Length inner body46 Ám33-46 Ám
Breadth inner body44 Ám36-60 Ám
Width of girdle4 Ám3- 8 Ám
Height of ledges3 Ám1- 4 Ám
Height of apical horn10 Ám4-11 Ám
Affinities:
Clarke and Verdier, 1967, p.31: G. extensa differs from G. cassidata in the presence of a cavity situated antapically and formed by an extension of the outer wall. Therefore the inner body and the outer wall are not in contact in the antapical region. Such a feature is absent in G. cassidata where the inner body and outer wall are in contact at the antapex and where the antapical plate is bordered by a high denticulate ledge.