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Gonyaulacysta canadensis
Gonyaualcysta canadensis Pocock, 1972
Originally Gonyaulacysta, subsequently Hystrichogonyaulax, thirdly Rhynchodiniopsis.
Taxonomic senior synonym: Gonyaulax (as Gonyaulacysta now Rhynchodiniopsis) cladophora, according to Fisher and Riley (1980, p.320) and Kunz (1990, p.23).
Jansonius, 1986, retained the species - as Rhynchodiniopsis canadensis (Pocock, 1972) Jansonius, 1986 - but Kunz, 1990, agreed with Fisher and Riley, 1980).
Holotype: Pocock, 1972, pl.24, fig.1; Jan du Chêne et al., 1986, pl.97, figs.1-4
Locus typicus: Imperial Tidewater Carlyle, Western Canada
Stratum typicum: Oxfordian-Kimmeridgian
Original description: Pocock, 1972, p.89
Vesicle more or less isodiametric; epitheca and hypotheca hemispherical; epitheca tapers towards the apex, being terminated by a short apical horn about 10.0 Ám long and 12.0 Ám wide (see diagram); hypotheca smoothly rounded; no antapical processes; transverse furrow helicoidal; strongly developed, longitudinal furrow less well marked; parallel-sided; tabulation 4", 6", 6""", 1""""; archeopyle precingular with a simple free operculum, comprises plate 3", not always developed; sutures reflected onto surface of vesicle as low raised ridges up to 1.0 µm wide; rows of thin, pinnate spines 2.5 (4.0) 7.7 µm long and up to 1.0 µm wide, spaced 2.0 (4.1) 8.8 µm apart line the crests of the ridges; vesicle two-layered; capsule very thin, smooth; outer layer 1.0-1.5 µm thick; scabrate; colour pale yellow; length of vesicle 99.0 (104.5) 110.0 µm; width of vesicle 77.0 (91.4) 106.0 µm.
Originally Gonyaulacysta, subsequently Hystrichogonyaulax, thirdly Rhynchodiniopsis.
Taxonomic senior synonym: Gonyaulax (as Gonyaulacysta now Rhynchodiniopsis) cladophora, according to Fisher and Riley (1980, p.320) and Kunz (1990, p.23).
Jansonius, 1986, retained the species - as Rhynchodiniopsis canadensis (Pocock, 1972) Jansonius, 1986 - but Kunz, 1990, agreed with Fisher and Riley, 1980).
Holotype: Pocock, 1972, pl.24, fig.1; Jan du Chêne et al., 1986, pl.97, figs.1-4
Locus typicus: Imperial Tidewater Carlyle, Western Canada
Stratum typicum: Oxfordian-Kimmeridgian
Original description: Pocock, 1972, p.89
Vesicle more or less isodiametric; epitheca and hypotheca hemispherical; epitheca tapers towards the apex, being terminated by a short apical horn about 10.0 Ám long and 12.0 Ám wide (see diagram); hypotheca smoothly rounded; no antapical processes; transverse furrow helicoidal; strongly developed, longitudinal furrow less well marked; parallel-sided; tabulation 4", 6", 6""", 1""""; archeopyle precingular with a simple free operculum, comprises plate 3", not always developed; sutures reflected onto surface of vesicle as low raised ridges up to 1.0 µm wide; rows of thin, pinnate spines 2.5 (4.0) 7.7 µm long and up to 1.0 µm wide, spaced 2.0 (4.1) 8.8 µm apart line the crests of the ridges; vesicle two-layered; capsule very thin, smooth; outer layer 1.0-1.5 µm thick; scabrate; colour pale yellow; length of vesicle 99.0 (104.5) 110.0 µm; width of vesicle 77.0 (91.4) 106.0 µm.