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Phanerodinium distinctum
Phanerodinium distinctum (Davey, 1969) Below, 1987
Now Microdinium. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams (1989, p.244) retained this species in Microdinium.Questionable
Tax. sr. synonym of Microdinium? (as Phanerodinium) variospinum Davey, 1969, according to Below, 1987.
Questionable tax. sr. synonym of Microdinium glabrum Cookson and Eisenack, 1974, according to Below, 1987;
Questionable tax. sr. synonym of Microdinium (as Phanerodinium) opacum Brideaux, 1971, according to Below, 1987. Lentin and Williams, 1989 retained this species in Microdinium Cookson and Eisenack, 1960.
Holotype: Davey, 1969, p.2, figs.9-10; text-fig. 13D-E
Locus typicus: Fetchum Mill, England
Stratum typicum: Early Cenomanian
Original diagnosis: Davey, 1969, p. 133: Microdinium distinctum
Shell subspherical, thick-walled, smooth. Sutural crests well developed bearing short, broad, flat-topped spines. Reflected tabulation I, oa, 6", 6""", 1p, 1""""; plates 1" and 6" very reduced and cingular plates absent. Cingulum broad, weakly laevo-rotatory.
Original description: Davey, 1969, p. 133-134: Microdinium distinctum
The shell wall is relatively thick, c. 1µm, and develops pronounced ridges at the plate boundaries. The sutural spines are closely set, very broad and flat distally.
The precingular plates are generally smaller than the postcingular plates. Plates 1" and 6" are small and appear as slight projections in the ventral area. This is widest posteriorly and is open anteriorly. The apical plate is six-sided and is lost in archaeopyle formation. The archaeopyle possesses slits extending posteriorly between the precingular plates.
Now Microdinium. Originally (and now) Microdinium, subsequently Phanerodinium. Lentin and Williams (1989, p.244) retained this species in Microdinium.Questionable
Tax. sr. synonym of Microdinium? (as Phanerodinium) variospinum Davey, 1969, according to Below, 1987.
Questionable tax. sr. synonym of Microdinium glabrum Cookson and Eisenack, 1974, according to Below, 1987;
Questionable tax. sr. synonym of Microdinium (as Phanerodinium) opacum Brideaux, 1971, according to Below, 1987. Lentin and Williams, 1989 retained this species in Microdinium Cookson and Eisenack, 1960.
Holotype: Davey, 1969, p.2, figs.9-10; text-fig. 13D-E
Locus typicus: Fetchum Mill, England
Stratum typicum: Early Cenomanian
Original diagnosis: Davey, 1969, p. 133: Microdinium distinctum
Shell subspherical, thick-walled, smooth. Sutural crests well developed bearing short, broad, flat-topped spines. Reflected tabulation I, oa, 6", 6""", 1p, 1""""; plates 1" and 6" very reduced and cingular plates absent. Cingulum broad, weakly laevo-rotatory.
Original description: Davey, 1969, p. 133-134: Microdinium distinctum
The shell wall is relatively thick, c. 1µm, and develops pronounced ridges at the plate boundaries. The sutural spines are closely set, very broad and flat distally.
The precingular plates are generally smaller than the postcingular plates. Plates 1" and 6" are small and appear as slight projections in the ventral area. This is widest posteriorly and is open anteriorly. The apical plate is six-sided and is lost in archaeopyle formation. The archaeopyle possesses slits extending posteriorly between the precingular plates.