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Rhynchodiniopsis gochtii
Rhychidiniopsis gochtii (Pocock, 1972) Jansonius in Jan du Chêne et al., 1986
Originally Scriniodinium, subsequently Scriniodinium?, thirdly Endoscrinium, fourthly (and now) Rhynchodiniopsis. This species was reillustrated and redescribed by Jansonius, 1986; however, the proposed new combination was published in Jan du Chêne et al., 1986 several months earlier.
Holotype: Pocock, 1972, pl.22, fig.12; Jan du Chêne et al., 1986, pl.93, figs.4-8
Locus typicus: Royalite DeWinton, Westeren Canada
Stratum typicum: Late Bajocian
Original description: Pocock, 1972, p.90: Scriniodinium gochtii
Vesicle more or less isodiametric; epitheca and hypotheca hemispherical; no apical or antapical processes developed; transverse furrow well defined; helicoidal; longitudinal furrow more or less parallel-sided; tabulation 1", 6", 5""", 1""""; no archeopyle seen; suture reflected onto surface of vesicle as low ridges about 1.5 µm wide surmounted by narrow crests 5.0--7.0 µm high, supported by thickened rods spaced 2.0--5.0 µm apart; rods straight; joined at their tips; sometimes bifurcating (see diagram); vesicle two-layered; capsule thin-walled; smooth; tightly appressed to outer layer; outer layer about 1.0 µm thick; granulose; colour pale yellow; length of vesicle 90.0--93.0 µm; equatorial diameter 84.0--88.0 µm.
Supplemental description: Jansonius, 1986, p.218
(Holotype) 115 x 100 µm, vesicle broadly ovoid in outline, both apex and antapex broadly rounded, hypocyst slightly larger than epicyst. Wall roughened-- shagreenate--shallowly pitted, ca 0.5 µm thick all over. Paratabulation marked by thin sutural crests (ca 0.5 µm wide, tapering to almost nothing, 1-2.5 µm high) reinforced by radial spines which maintain the thickness of the base of the crest, and which are distally interconnected by a single trabecular strand; spines project generally 5-6 µm from cell wall, but as much as 10 µm at lateral cingular regions, and as little as 1 µm in some minor rows ("major rows" are indicated by a heavier line in Text-Figure 14). Many spines bifurcate at about 1/2-2/3 Of their length, others only show some knobs there indicating rudimentary branching. Especially in the epicyst and along the minor sutural crests, the distal strand connecting the spines may be interrupted, in which case each spine carries two curved lateral branches, giving them an anchor-shaped appearance. In between these well developed spines the crests show a number of rudimentary spinules or denticulations. The crests delineating the apical plates are up to 15 µm tall, solid,and with distal thickenings that project above the apex to form a structure resembling an apical horn; it seems probable that preapicals are present, but none can be made out. There is no evidence of a separate internal body, or differentiation of a second wall layer. The operculum of the precingular archeopyle (3") is lost.
Originally Scriniodinium, subsequently Scriniodinium?, thirdly Endoscrinium, fourthly (and now) Rhynchodiniopsis. This species was reillustrated and redescribed by Jansonius, 1986; however, the proposed new combination was published in Jan du Chêne et al., 1986 several months earlier.
Holotype: Pocock, 1972, pl.22, fig.12; Jan du Chêne et al., 1986, pl.93, figs.4-8
Locus typicus: Royalite DeWinton, Westeren Canada
Stratum typicum: Late Bajocian
Original description: Pocock, 1972, p.90: Scriniodinium gochtii
Vesicle more or less isodiametric; epitheca and hypotheca hemispherical; no apical or antapical processes developed; transverse furrow well defined; helicoidal; longitudinal furrow more or less parallel-sided; tabulation 1", 6", 5""", 1""""; no archeopyle seen; suture reflected onto surface of vesicle as low ridges about 1.5 µm wide surmounted by narrow crests 5.0--7.0 µm high, supported by thickened rods spaced 2.0--5.0 µm apart; rods straight; joined at their tips; sometimes bifurcating (see diagram); vesicle two-layered; capsule thin-walled; smooth; tightly appressed to outer layer; outer layer about 1.0 µm thick; granulose; colour pale yellow; length of vesicle 90.0--93.0 µm; equatorial diameter 84.0--88.0 µm.
Supplemental description: Jansonius, 1986, p.218
(Holotype) 115 x 100 µm, vesicle broadly ovoid in outline, both apex and antapex broadly rounded, hypocyst slightly larger than epicyst. Wall roughened-- shagreenate--shallowly pitted, ca 0.5 µm thick all over. Paratabulation marked by thin sutural crests (ca 0.5 µm wide, tapering to almost nothing, 1-2.5 µm high) reinforced by radial spines which maintain the thickness of the base of the crest, and which are distally interconnected by a single trabecular strand; spines project generally 5-6 µm from cell wall, but as much as 10 µm at lateral cingular regions, and as little as 1 µm in some minor rows ("major rows" are indicated by a heavier line in Text-Figure 14). Many spines bifurcate at about 1/2-2/3 Of their length, others only show some knobs there indicating rudimentary branching. Especially in the epicyst and along the minor sutural crests, the distal strand connecting the spines may be interrupted, in which case each spine carries two curved lateral branches, giving them an anchor-shaped appearance. In between these well developed spines the crests show a number of rudimentary spinules or denticulations. The crests delineating the apical plates are up to 15 µm tall, solid,and with distal thickenings that project above the apex to form a structure resembling an apical horn; it seems probable that preapicals are present, but none can be made out. There is no evidence of a separate internal body, or differentiation of a second wall layer. The operculum of the precingular archeopyle (3") is lost.