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Rosswangia
From Williams et al., 2017:
[Rosswangia, Wille and Gocht, 1985, p. 123, 125, 127, 129
Tax. jr. syn.: Dinaurelia, according to Below (1987b, p.29) — however, Stover and Williams (1987, p.79) and Lentin and Williams (1989, p.110) retained Dinaurelia.
Type species: Rosswangia simplex, Wille and Gocht, 1985 (pl.5, figs.7a–b)]
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Original description: [Wille and Gocht, 1985]: (Translation: Stover and Williams, 1987, p. 119):
Description:
Cysts solitary, nearly spherical. Single-layer wall scabrate. Without girdle and sulcus. Parasutures sometimes indicated on the operculum. Archeopyle: tAtIa (following Evitt, 1967). Operculum single, with six angular lobes. When the archaeopyle is open, there are seven separated paracingular flaps along the archeaopyle margin: 1`` and 7``, narrow, planate; 4`` relatively narrow, symmetrically camerate; 2``, 3``, 5``, 6`` asymmetrically camerate.
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Modified description:
Stover and Williams 1987, p. 197-198:
Synopsis:
Cysts proximate, subspherical; autophragm finely ornamented; paratabulation indicated on epicyst only, formula: 4`, 4a, 7``; archeopyle combined apical and intercalary, type [tAtI]@.
Description:
Shape: Subspherical.
Wall relationships: Autophragm only.
Wall features: No prominent parasutural features; surface ornamented with features of low relief.
Archeopyle: Combined apical and intercalary, type [tAtI]@; operculum has six, marginal and apically camerate paraplates and a narrow isthmus. Paratabulation: Expressed on epicyst only, indicated by outlines of operculum and anterior portions of precingular paraplates; formula: 4`, 4a, 7``. Paraplates 1`` and 7`` planate; other precingular paraplates camerate.
Paracingulum: Typically not indicated.
Parasulcus: Not indicated.
Size: Small, diameter about 25-40 µm.
Affinities:
Comparison of selected features of Rosswangia, Mancodinium Morgenroth 1970, Maturodinium Morgenroth 1970 and Dapcodinium Evitt 1961.
Rosswangia: Paratabulation on epicyst only. Archeopyle: [4A4I]@. Operculum: Adnate, a single opercular piece.
Mancodinium: Paratabulation on epicyst only. Archeopyle: [4A4I]. Operculum: Free, a single opercular piece.
Maturodinium: Paratabulation on epicyst only. Archeopyle: [4A]@+?4I]. Operculum: 5 opercular pieces; ?4 intercalaries free, 4 apicals form a single adnate opercular piece.
Apcodinium: Paratabulation on epicyst and hypocyst. Archeopyle: Type uncertain; presumably mainly apical. Operculum: Details noy known, probably adnate.
Rosswangia differs from Kallosphaeridium De Coninck 1969 emended Jan du Chêne et al. 1985, which also has an adnate operculum, in having more intercalary paraplates. Wille and Gocht (1985) regarded Rosswangia as the solitary counterpart of the chain-forming genus Dinaurelia Wille and Gocht 1985.
[Rosswangia, Wille and Gocht, 1985, p. 123, 125, 127, 129
Tax. jr. syn.: Dinaurelia, according to Below (1987b, p.29) — however, Stover and Williams (1987, p.79) and Lentin and Williams (1989, p.110) retained Dinaurelia.
Type species: Rosswangia simplex, Wille and Gocht, 1985 (pl.5, figs.7a–b)]
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Original description: [Wille and Gocht, 1985]: (Translation: Stover and Williams, 1987, p. 119):
Description:
Cysts solitary, nearly spherical. Single-layer wall scabrate. Without girdle and sulcus. Parasutures sometimes indicated on the operculum. Archeopyle: tAtIa (following Evitt, 1967). Operculum single, with six angular lobes. When the archaeopyle is open, there are seven separated paracingular flaps along the archeaopyle margin: 1`` and 7``, narrow, planate; 4`` relatively narrow, symmetrically camerate; 2``, 3``, 5``, 6`` asymmetrically camerate.
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Modified description:
Stover and Williams 1987, p. 197-198:
Synopsis:
Cysts proximate, subspherical; autophragm finely ornamented; paratabulation indicated on epicyst only, formula: 4`, 4a, 7``; archeopyle combined apical and intercalary, type [tAtI]@.
Description:
Shape: Subspherical.
Wall relationships: Autophragm only.
Wall features: No prominent parasutural features; surface ornamented with features of low relief.
Archeopyle: Combined apical and intercalary, type [tAtI]@; operculum has six, marginal and apically camerate paraplates and a narrow isthmus. Paratabulation: Expressed on epicyst only, indicated by outlines of operculum and anterior portions of precingular paraplates; formula: 4`, 4a, 7``. Paraplates 1`` and 7`` planate; other precingular paraplates camerate.
Paracingulum: Typically not indicated.
Parasulcus: Not indicated.
Size: Small, diameter about 25-40 µm.
Affinities:
Comparison of selected features of Rosswangia, Mancodinium Morgenroth 1970, Maturodinium Morgenroth 1970 and Dapcodinium Evitt 1961.
Rosswangia: Paratabulation on epicyst only. Archeopyle: [4A4I]@. Operculum: Adnate, a single opercular piece.
Mancodinium: Paratabulation on epicyst only. Archeopyle: [4A4I]. Operculum: Free, a single opercular piece.
Maturodinium: Paratabulation on epicyst only. Archeopyle: [4A]@+?4I]. Operculum: 5 opercular pieces; ?4 intercalaries free, 4 apicals form a single adnate opercular piece.
Apcodinium: Paratabulation on epicyst and hypocyst. Archeopyle: Type uncertain; presumably mainly apical. Operculum: Details noy known, probably adnate.
Rosswangia differs from Kallosphaeridium De Coninck 1969 emended Jan du Chêne et al. 1985, which also has an adnate operculum, in having more intercalary paraplates. Wille and Gocht (1985) regarded Rosswangia as the solitary counterpart of the chain-forming genus Dinaurelia Wille and Gocht 1985.