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Amphorosphaeridium
From Williams et al., 2017:
[Amphorosphaeridium, Davey, 1969c, p. 30
Tax. jr. syn. of Lanternosphaeridium Morgenroth, 1966, according to Norvick in Norvick and Burger, 1976. Stover and Evitt, 1978, retained Amphorossphaeridium as a separate genus.
Type species: Amphorosphaeridium fenestratum, Davey, 1969c (pl.3, figs.1–2)]
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Original description: [Davey, 1969]:
Description:
Subspherical to ovoidal chorate dinoflagellate cysts possessing a two-layered wall. The periphragm layer is fibrous and variably pitted. Intratabular processes well developed. They are fibrous and typically hollow. Apical and usually antapical processes distinctive. Archaeopyle precingular (type P).
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Modified description:
Stover and Evitt, 1978, p. 140:
Synopsis:
Cysts skolochorate, acavate; body subspherical with fibrous, hollow processes; processes nontabular, or combination of nontabular and infrequent intratabular; apical and usually antapical processes distinctive; paratabulation expressed clearly by archeopyle only; archeopyle precingular, Type P.
Description:
Shape: Body subspherical.
Wall Relationships: Endophragm and periphragm appressed between processes.
Wall Features: No parasutural features. Processes nontabular, or combination of nontabular and infrequent intratabular; tubular, fibrous, simple or branched, and generally open distally; apical and usually antapical processes distinctive. Periphragm fibrous and variably pitted.
Paratabulation: Generally indicated by archeopyle only; indicated additionally by occasional intratabular processes.
Archeopyle: Precingular, Type P (3" only); operculum free.
Paracingulum: Generally not indicated; position may be suggested by faint alignment of processes.
Parasulcus: Not indicated.
Size: Large.
Affinities:
Amphorosphaeridium differs from Fibrocysta in having a spherical instead of an ellipsoidal body and in lacking a short to long protrusion at one or both poles. It differs from Cordosphaeridium in having more numerous, mainly nontabular processes and distinctive polar processes. It differs from Exochosphaeridium in having hollow and more complex processes, which on Exochosphaeridium are apparently solid and less branched distally. Morphology of the type species does not support the synonymy with Lanternosphaeridium claimed by Norvick (in Norvick & Burger 1976).
[Amphorosphaeridium, Davey, 1969c, p. 30
Tax. jr. syn. of Lanternosphaeridium Morgenroth, 1966, according to Norvick in Norvick and Burger, 1976. Stover and Evitt, 1978, retained Amphorossphaeridium as a separate genus.
Type species: Amphorosphaeridium fenestratum, Davey, 1969c (pl.3, figs.1–2)]
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Original description: [Davey, 1969]:
Description:
Subspherical to ovoidal chorate dinoflagellate cysts possessing a two-layered wall. The periphragm layer is fibrous and variably pitted. Intratabular processes well developed. They are fibrous and typically hollow. Apical and usually antapical processes distinctive. Archaeopyle precingular (type P).
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Modified description:
Stover and Evitt, 1978, p. 140:
Synopsis:
Cysts skolochorate, acavate; body subspherical with fibrous, hollow processes; processes nontabular, or combination of nontabular and infrequent intratabular; apical and usually antapical processes distinctive; paratabulation expressed clearly by archeopyle only; archeopyle precingular, Type P.
Description:
Shape: Body subspherical.
Wall Relationships: Endophragm and periphragm appressed between processes.
Wall Features: No parasutural features. Processes nontabular, or combination of nontabular and infrequent intratabular; tubular, fibrous, simple or branched, and generally open distally; apical and usually antapical processes distinctive. Periphragm fibrous and variably pitted.
Paratabulation: Generally indicated by archeopyle only; indicated additionally by occasional intratabular processes.
Archeopyle: Precingular, Type P (3" only); operculum free.
Paracingulum: Generally not indicated; position may be suggested by faint alignment of processes.
Parasulcus: Not indicated.
Size: Large.
Affinities:
Amphorosphaeridium differs from Fibrocysta in having a spherical instead of an ellipsoidal body and in lacking a short to long protrusion at one or both poles. It differs from Cordosphaeridium in having more numerous, mainly nontabular processes and distinctive polar processes. It differs from Exochosphaeridium in having hollow and more complex processes, which on Exochosphaeridium are apparently solid and less branched distally. Morphology of the type species does not support the synonymy with Lanternosphaeridium claimed by Norvick (in Norvick & Burger 1976).