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Millioudodinium saetigerum
Millioudodinium saetigerum McIntyre and Brideaux, 1980
Now Cribroperidinium?. Originally Millioudodinium, subsequently (and now) Cribroperidinium?.
Holotype: McIntyre and Brideaux, 1980, pl.3, figs.2-3,7; Jan du Chêne et al., 1986, pl.24, figs.4-6
Locus typicus: Martin Creek, District of Mackenzie, Canada
Stratum typicum: Valanginian
Original diagnosis: McIntyre and Brideaux, 1980, p. 15
Phragma: Periphragm - About 1 Ám thick, punctate, bearing small, scattered intratabular apiculate sculpture elements and densely spaced parasutural apiculae about 0.5-1.0 Ám high. Endophragm - About 1.0 Ám thick, surface presurnably smooth or scabrate.
Paratabulation: Pericyst - Parasutural apiculae denote a paratabulation of 4", 6", 6c, 5"""-?6""", ?1p, 1"""". Endocyst - Paratabulation not observed. Pericingulum - Helicoid, displaced one pericingular width (5-7 Ám), slightly indented; six cingular paraplates denoted by parasutural apiculae. Perisulcus - Present; denoted by a shallow S-shaped depression, narrow anteriorly, broadening posteriorly on the hypopericyst, and widest at the posterior end.
Archeopyle: Precingular, Type P(3"). Operculum free, simple, longer than broad, rounded-polygonal.
Variation: Periphragm of an amorphous consistency, apparently degraded, obscuring details of paratabulation particularly at the apex and antapex.
Dimensions: Pericyst length, 70-87 Ám, width 51-70 Ám.
Affinities:
McIntyre and Brideaux, 1980, p. 15: Millioudodinium episomum (Sarjeant) Stover and Evitt, 1978 has thin parasutural spinelets connected distally by trabecula; Gonyaulacysta microceras Eisenack, 1958 has low, narrow crests, in places bearing small spines; Apteodinium nuciforme (Deflandre) Stover and Evitt, 1978 is very coarsely granular and thick walled; and Millioudodinium pallum (Sarjeant) Stover and Evitt, 1978 has paratabulatlon denoted by very short spines arising from low ridges.
Now Cribroperidinium?. Originally Millioudodinium, subsequently (and now) Cribroperidinium?.
Holotype: McIntyre and Brideaux, 1980, pl.3, figs.2-3,7; Jan du Chêne et al., 1986, pl.24, figs.4-6
Locus typicus: Martin Creek, District of Mackenzie, Canada
Stratum typicum: Valanginian
Original diagnosis: McIntyre and Brideaux, 1980, p. 15
Phragma: Periphragm - About 1 Ám thick, punctate, bearing small, scattered intratabular apiculate sculpture elements and densely spaced parasutural apiculae about 0.5-1.0 Ám high. Endophragm - About 1.0 Ám thick, surface presurnably smooth or scabrate.
Paratabulation: Pericyst - Parasutural apiculae denote a paratabulation of 4", 6", 6c, 5"""-?6""", ?1p, 1"""". Endocyst - Paratabulation not observed. Pericingulum - Helicoid, displaced one pericingular width (5-7 Ám), slightly indented; six cingular paraplates denoted by parasutural apiculae. Perisulcus - Present; denoted by a shallow S-shaped depression, narrow anteriorly, broadening posteriorly on the hypopericyst, and widest at the posterior end.
Archeopyle: Precingular, Type P(3"). Operculum free, simple, longer than broad, rounded-polygonal.
Variation: Periphragm of an amorphous consistency, apparently degraded, obscuring details of paratabulation particularly at the apex and antapex.
Dimensions: Pericyst length, 70-87 Ám, width 51-70 Ám.
Affinities:
McIntyre and Brideaux, 1980, p. 15: Millioudodinium episomum (Sarjeant) Stover and Evitt, 1978 has thin parasutural spinelets connected distally by trabecula; Gonyaulacysta microceras Eisenack, 1958 has low, narrow crests, in places bearing small spines; Apteodinium nuciforme (Deflandre) Stover and Evitt, 1978 is very coarsely granular and thick walled; and Millioudodinium pallum (Sarjeant) Stover and Evitt, 1978 has paratabulatlon denoted by very short spines arising from low ridges.