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Wrevittia perforobtusa
Wrevittia ?perforobtusa (Duxbury, 1977, p.39, pl.1, fig.1; text-fig.13) Helenes and Lucas-Clark, 1997, p.192.
Holotype: Duxbury, 1977, pl.1, fig.1; text-fig.13; Jan du Chêne et al., 1986a, pl.44, figs.1–2.
Originally Gonyaulacysta, subsequently Gonyaulacysta?, thirdly (and now) Wrevittia?.
Questionable assignment: Helenes and Lucas-Clark (1997, p.192).
Age: Hauterivian.
Original diagnosis: Duxbury, 1977, p. 39
Periphragm smooth to finely granular, produced into a short blunt apical horn. Tabulation 4", 6", ?6""", 1p, 1"""", outlined by very distinctive sutural crests. These are fairly high, proximally entire and distally produced into evenly spaced denticles which are parallel-sided and flat-ended. Typically, just below the line of denticulations, there is a single row of perforations, each being about 1 µm across.
Observed Dimensions: Holotype 57x51 µm. Overall 59(54)46x51(46)39 µm.
Affinities:
Duxdury, 1977, p. 39
In having perforations running along the crests, Gonyaulacysta perforobtusa resembles Gonyaulacysta ordocava. However, in most other respects, the two species are very different.
Holotype: Duxbury, 1977, pl.1, fig.1; text-fig.13; Jan du Chêne et al., 1986a, pl.44, figs.1–2.
Originally Gonyaulacysta, subsequently Gonyaulacysta?, thirdly (and now) Wrevittia?.
Questionable assignment: Helenes and Lucas-Clark (1997, p.192).
Age: Hauterivian.
Original diagnosis: Duxbury, 1977, p. 39
Periphragm smooth to finely granular, produced into a short blunt apical horn. Tabulation 4", 6", ?6""", 1p, 1"""", outlined by very distinctive sutural crests. These are fairly high, proximally entire and distally produced into evenly spaced denticles which are parallel-sided and flat-ended. Typically, just below the line of denticulations, there is a single row of perforations, each being about 1 µm across.
Observed Dimensions: Holotype 57x51 µm. Overall 59(54)46x51(46)39 µm.
Affinities:
Duxdury, 1977, p. 39
In having perforations running along the crests, Gonyaulacysta perforobtusa resembles Gonyaulacysta ordocava. However, in most other respects, the two species are very different.