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Pluriarvalium
From Williams et al., 2017:
[Pluriarvalium, Sarjeant, 1962b, p. 260
Tax. sr. syn.: Pareodinia, according to Wiggins (1975, p.102) — however, Stover and Evitt (1978, p.119) retained Pluriarvalium.
Type species: Pluriavalium osmingtonense, Sarjeant, 1962b (pl.1, fig.5)]
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Original description: [Sarjeant, 1962]:
Description:
Dinoflagellates of globular to oval shape, with distinct transverse and longitudinal furrows, the latter extending across the epitheca on to the hypotheca, and with an apical horn.
Tabulation: up to five apical plates, one to three anterior intercalary plates, six pre-equatorial plates, six post-equatorial plates, one posterior intercalary plate, one posterior ventral plate corresponding in position to the posterior extension of the longitudinal furrow, and a single antapical plate partially or completely surrounded by a posterior circle of small plates.
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Modified description:
Stover and Evitt, 1978, p. 119:
Synopsis:
Cysts proximate, ellipsoidal, with an apical horn; paratabulation indicated by low to moderately high parasutural ridges delimiting numerous preapical and posterior intercalary paraplates in addition to precingular, paracingular, and postcingular paraplates; archeopyle intercalary, Type I or 3I.
Description:
Shape: Ellipsoidal with a slender short apical horn.
Wall Relationship: Autophragm only; surrounding amorphous cloak, which may or may not be preserved, is not considered a wall layer.
Wall Features: Parasutural ridges low to moderately high; crests smooth, enticulate, setate or fimbriate. Surface between parasutural ridges smooth or with features of low relief.
Paratabulation: Indicated by parasutural features; formula: 7pr, 6`, 5-6a, 5-6", 2-7c, 7"`, 3"", and an uncertain number of posterior intercalary and sulcal paraplates. Paratabulation not known to be expressed completely on a single specimen.
Archeopyle: Intercalary, either Type I or 3I; operculum free.
Paracingulum: Indicated by from two to seven cingular paraplates, or by transverse parallel parasutural ridges alone.
Parasulcus: Longitudinally elongate area, wider antapically than apically, confined mainly to hypocyst; may contain paraplates, exact number uncertain.
Size: Intermediate.
Affinities:
Pluriarvalium differs from Paragonyaulacysta in having numerous preapical and posterior intercalary paraplates in addition to precingular, paracingular, and postcingular ones. Pareodinia lacks indications of paratabulation other than archeopyle.
[Pluriarvalium, Sarjeant, 1962b, p. 260
Tax. sr. syn.: Pareodinia, according to Wiggins (1975, p.102) — however, Stover and Evitt (1978, p.119) retained Pluriarvalium.
Type species: Pluriavalium osmingtonense, Sarjeant, 1962b (pl.1, fig.5)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Sarjeant, 1962]:
Description:
Dinoflagellates of globular to oval shape, with distinct transverse and longitudinal furrows, the latter extending across the epitheca on to the hypotheca, and with an apical horn.
Tabulation: up to five apical plates, one to three anterior intercalary plates, six pre-equatorial plates, six post-equatorial plates, one posterior intercalary plate, one posterior ventral plate corresponding in position to the posterior extension of the longitudinal furrow, and a single antapical plate partially or completely surrounded by a posterior circle of small plates.
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Modified description:
Stover and Evitt, 1978, p. 119:
Synopsis:
Cysts proximate, ellipsoidal, with an apical horn; paratabulation indicated by low to moderately high parasutural ridges delimiting numerous preapical and posterior intercalary paraplates in addition to precingular, paracingular, and postcingular paraplates; archeopyle intercalary, Type I or 3I.
Description:
Shape: Ellipsoidal with a slender short apical horn.
Wall Relationship: Autophragm only; surrounding amorphous cloak, which may or may not be preserved, is not considered a wall layer.
Wall Features: Parasutural ridges low to moderately high; crests smooth, enticulate, setate or fimbriate. Surface between parasutural ridges smooth or with features of low relief.
Paratabulation: Indicated by parasutural features; formula: 7pr, 6`, 5-6a, 5-6", 2-7c, 7"`, 3"", and an uncertain number of posterior intercalary and sulcal paraplates. Paratabulation not known to be expressed completely on a single specimen.
Archeopyle: Intercalary, either Type I or 3I; operculum free.
Paracingulum: Indicated by from two to seven cingular paraplates, or by transverse parallel parasutural ridges alone.
Parasulcus: Longitudinally elongate area, wider antapically than apically, confined mainly to hypocyst; may contain paraplates, exact number uncertain.
Size: Intermediate.
Affinities:
Pluriarvalium differs from Paragonyaulacysta in having numerous preapical and posterior intercalary paraplates in addition to precingular, paracingular, and postcingular ones. Pareodinia lacks indications of paratabulation other than archeopyle.