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Gonyaulacysta perforobtusa
Gonyaulacysta perforobtusa Duxbury 1977
NOW Wrevittia?. Originally Gonyaulacysta, subsequently Gonyaulacysta?, thirdly Wrevittia?. Questionable assignment: Sarjeant (1982b, p.28) - however, Jan du Chêne et al. (1986a, p.131) included the species in Gonyaulacysta without question.
Holotype: Duxbury 1977, pl. 1, fig. 1, text-fig.13; Jan du Chene et al., 1986, pl.44, figs.1-2
Locus typicus: Speeton Clay, Speeton, England
Stratum typicum: 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 Ám across.
Observed Dimensions: Holotype 57x51 Ám. Overall 59(54)46x51(46)39 Ám.
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.
NOW Wrevittia?. Originally Gonyaulacysta, subsequently Gonyaulacysta?, thirdly Wrevittia?. Questionable assignment: Sarjeant (1982b, p.28) - however, Jan du Chêne et al. (1986a, p.131) included the species in Gonyaulacysta without question.
Holotype: Duxbury 1977, pl. 1, fig. 1, text-fig.13; Jan du Chene et al., 1986, pl.44, figs.1-2
Locus typicus: Speeton Clay, Speeton, England
Stratum typicum: 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 Ám across.
Observed Dimensions: Holotype 57x51 Ám. Overall 59(54)46x51(46)39 Ám.
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.