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Svalbardella
From Williams et al., 2017:
[Svalvardella, Manum, 1960, p. 21
Tax. jr. syn.: Palaeocystodinium, according to Lindgren (1984, p.186) — however, Wrenn and Hart (1988, p.361–362) retained Palaeocystodinium.
Type species: Svalbardella cooksoniae, Manum, 1960 (pl.1, figs.1–3; text-fig.2)]
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Original description: [Manum, 1960]:
Description:
Shell of planktonic microorganisms. Shape fusiform with somewhat swollen middle part and blunt ends. No appendages. Girdle approximately equatorial. Middle part of shell entirely filled by a thin-walled ellipsoid body.
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Modified description:
Stover and Evitt, 1978, p. 126:
Synopsis:
Cysts proximate, cornucavate or circumcavate, elongate ellipsoidal with single bluntly rounded apical and antapical horns at each pole; paratabulation indicated by archeopyle and parasutural features; archeopyle intercalary, Type I, archeopyle index <0.5.
Description:
Shape: Elongate ellipsoidal, with bluntly rounded ends.
Wall relationships: Cysts cornucavate or circumcavate; endocyst elongate ellipsoidal.
Wall features: Parasutural features consist of linear markings or low ridges, which are smooth or denticulate; parasutural features generally limited to precingular and postcingular areas. Periphragm finely reticulate or has scattered features of low relief.
Paratabulation: Indicated by archeopyle and parasutural features; formula unknown.
Archeopyle: Intercalary, Type I (2a only); height greater than width; archeopyle index <0.5; operculum normally free.
Paracingulum: Indicated by low, parallel, transverse parasutural ridges.
Parasulcus: Generally not indicated.
Size: Large.
Affinities:
Svalbardella differs from Paleocystodinium in having bluntly rounded apical and antapical horns and indications of paratabulation other than an archeopyle only.
[Svalvardella, Manum, 1960, p. 21
Tax. jr. syn.: Palaeocystodinium, according to Lindgren (1984, p.186) — however, Wrenn and Hart (1988, p.361–362) retained Palaeocystodinium.
Type species: Svalbardella cooksoniae, Manum, 1960 (pl.1, figs.1–3; text-fig.2)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Manum, 1960]:
Description:
Shell of planktonic microorganisms. Shape fusiform with somewhat swollen middle part and blunt ends. No appendages. Girdle approximately equatorial. Middle part of shell entirely filled by a thin-walled ellipsoid body.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt, 1978, p. 126:
Synopsis:
Cysts proximate, cornucavate or circumcavate, elongate ellipsoidal with single bluntly rounded apical and antapical horns at each pole; paratabulation indicated by archeopyle and parasutural features; archeopyle intercalary, Type I, archeopyle index <0.5.
Description:
Shape: Elongate ellipsoidal, with bluntly rounded ends.
Wall relationships: Cysts cornucavate or circumcavate; endocyst elongate ellipsoidal.
Wall features: Parasutural features consist of linear markings or low ridges, which are smooth or denticulate; parasutural features generally limited to precingular and postcingular areas. Periphragm finely reticulate or has scattered features of low relief.
Paratabulation: Indicated by archeopyle and parasutural features; formula unknown.
Archeopyle: Intercalary, Type I (2a only); height greater than width; archeopyle index <0.5; operculum normally free.
Paracingulum: Indicated by low, parallel, transverse parasutural ridges.
Parasulcus: Generally not indicated.
Size: Large.
Affinities:
Svalbardella differs from Paleocystodinium in having bluntly rounded apical and antapical horns and indications of paratabulation other than an archeopyle only.