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Cordosphaeridium
From Fensome et al., 2019:
Cordosphaeridium, Eisenack, 1963b, p.261.
Emendations: Morgenroth, 1968, p.548; Davey, 1969c, p.35; Sarjeant, 1981, p.100–101; He Chengquan, 1991, p.157–158,213.
Taxonomic junior synonym: Tityrosphaeridium, according to Lentin and Williams (1985, p.70; 1989, p.370) and Edwards (2001, p.G19).
Type: Klumpp, 1953, pl.18, figs.1–2, as Hystrichosphaeridium inodes.
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Original description: [Eisenack, 1963]: (Translation: Stover and Evitt, 1978, p. 146):
Diagnosis:
Hystrichospheres with spherical to (generally weakly) ellipsoidal shells, which are covered with approximately homogenous and rather regularly distributed radial appendages, which appear cord-like i.e., are formed of numerous thin, closely set fibres. A hollow space is, in general, not discernible; however, in some cases it can be present in relict fashion. Commonly the shell consists of two layers, of which the outer has a fibrous structure and (in all probability) the converging fibres constitute the processes. At the tips the fibres diverge in paintbrush-like fashion, however, they may also unite together in a net-like fashion.
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Emended description:
Davey, 1969:
Diagnosis:
Chorate, subspherical dinoflagellate cysts possessing a two-layered wall. The periphragm is fibrous and variably pitted, and gives rise to well developed intratabular fibrous processes. Polar processes not distinctive. Archaeopyle precingular, type P.
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Sarjeant, 1981:
Diagnosis:
Cyst spheroidal to broadly ovoidal, skolochorate. Phragma two-layered, with processes typically or constantly formed from the periphragm only.
Processes intratabular, solid or hollow, essentially cylindrical in shape yet of very variable form: they may be branched and expanded distally, but they are not linked distally by trabeculae or an enclosing membrane, partial or complete. The process walls are fibrous, the fibres with or without root-like proximal extensions. Parasutural or penitabular features are inconspicuous or lacking. Paratabulation gonyaulacacean, with the formula 3-4`, 6``, Oc, 5-6```, 0-1p, 1````, ?Os. The antapical process may be somewhat larger and more conspicuous than the others. Archaeopyle precingular, type P (3`` only); operculum free or loosely attached.
rejected by Lentin and Williams, 1985, p. 70, because it excludes the presence of cingular processes. This contention apparently resulted from Sarjeant`s misinterpretation of the holotype of the type species.
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Modified description:
Stover and Evitt 1978, p. 146-147:
Synopsis:
Cysts skolochorate, body subspherical, bearing 22 to about 30 fibrous, solid or hollow, mostly intratabular, processes; paratabulation gonyaulacacean, indicated by processes; archeopyle precingular, Type P.
Description:
Shape: Body subspherical.
Wall relationships: Endophragm and periphragm appressed between processes; wall layers rarely clearly differentiated.
Wall features: No parasutural features. Intratabular processes loosely fibrous, solid or hollow, and commonly branched and expanded distally;
periphragm between the processes faintly to coarsely ornamented, commonly fibrous.
Paratabulation: Indicated by intratabular processes; gonyaulacacean, process formula: 3-4`, 6``, 6c, 5-6```, 0-1p, 1````, 0-3s+?s. Processes in excess of the number required for one process per paraplate may be present. Additionally, some forms may have than less the number necessary for one process per paraplate owing to closely spaced processes having a common base; such processes could be interpreted as representing two paraplates.
Archeopyle: Precingular, Type P (3`` only); operculum free.
Paracingulum: Position indicated by six intratabular processes.
Parasulcus: Not clearly indicated; position suggested by few to several small slender processes.
Size: Intermediate to large.
Affinities:
Cordosphaeridium differs from Kleithriasphaeridium in having fibrous rather than smooth or faintly striate processes. Other genera with fibrous processes and precingular archeopyle include Amphorosphaeridium, Fibrocysta, Kenleyia, and Turbiosphaera. Amphorosphaeridium has mainly nontabular processes with only occasionally intratabular processes; Fibrocysta has a more elongate body than Cordosphaeridium and generally a larger number of paracingular processes; Kenleyia normally has fewer processes than Cordosphaeridium and they may be gonal rather than intratabular; Turbiosphaera is more elongate, its processes are typically wide and flat, and the paracingulum is represented by a shelf-like projection.
Cordosphaeridium, Eisenack, 1963b, p.261.
Emendations: Morgenroth, 1968, p.548; Davey, 1969c, p.35; Sarjeant, 1981, p.100–101; He Chengquan, 1991, p.157–158,213.
Taxonomic junior synonym: Tityrosphaeridium, according to Lentin and Williams (1985, p.70; 1989, p.370) and Edwards (2001, p.G19).
Type: Klumpp, 1953, pl.18, figs.1–2, as Hystrichosphaeridium inodes.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eisenack, 1963]: (Translation: Stover and Evitt, 1978, p. 146):
Diagnosis:
Hystrichospheres with spherical to (generally weakly) ellipsoidal shells, which are covered with approximately homogenous and rather regularly distributed radial appendages, which appear cord-like i.e., are formed of numerous thin, closely set fibres. A hollow space is, in general, not discernible; however, in some cases it can be present in relict fashion. Commonly the shell consists of two layers, of which the outer has a fibrous structure and (in all probability) the converging fibres constitute the processes. At the tips the fibres diverge in paintbrush-like fashion, however, they may also unite together in a net-like fashion.
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Emended description:
Davey, 1969:
Diagnosis:
Chorate, subspherical dinoflagellate cysts possessing a two-layered wall. The periphragm is fibrous and variably pitted, and gives rise to well developed intratabular fibrous processes. Polar processes not distinctive. Archaeopyle precingular, type P.
---------------------------------
Sarjeant, 1981:
Diagnosis:
Cyst spheroidal to broadly ovoidal, skolochorate. Phragma two-layered, with processes typically or constantly formed from the periphragm only.
Processes intratabular, solid or hollow, essentially cylindrical in shape yet of very variable form: they may be branched and expanded distally, but they are not linked distally by trabeculae or an enclosing membrane, partial or complete. The process walls are fibrous, the fibres with or without root-like proximal extensions. Parasutural or penitabular features are inconspicuous or lacking. Paratabulation gonyaulacacean, with the formula 3-4`, 6``, Oc, 5-6```, 0-1p, 1````, ?Os. The antapical process may be somewhat larger and more conspicuous than the others. Archaeopyle precingular, type P (3`` only); operculum free or loosely attached.
rejected by Lentin and Williams, 1985, p. 70, because it excludes the presence of cingular processes. This contention apparently resulted from Sarjeant`s misinterpretation of the holotype of the type species.
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Modified description:
Stover and Evitt 1978, p. 146-147:
Synopsis:
Cysts skolochorate, body subspherical, bearing 22 to about 30 fibrous, solid or hollow, mostly intratabular, processes; paratabulation gonyaulacacean, indicated by processes; archeopyle precingular, Type P.
Description:
Shape: Body subspherical.
Wall relationships: Endophragm and periphragm appressed between processes; wall layers rarely clearly differentiated.
Wall features: No parasutural features. Intratabular processes loosely fibrous, solid or hollow, and commonly branched and expanded distally;
periphragm between the processes faintly to coarsely ornamented, commonly fibrous.
Paratabulation: Indicated by intratabular processes; gonyaulacacean, process formula: 3-4`, 6``, 6c, 5-6```, 0-1p, 1````, 0-3s+?s. Processes in excess of the number required for one process per paraplate may be present. Additionally, some forms may have than less the number necessary for one process per paraplate owing to closely spaced processes having a common base; such processes could be interpreted as representing two paraplates.
Archeopyle: Precingular, Type P (3`` only); operculum free.
Paracingulum: Position indicated by six intratabular processes.
Parasulcus: Not clearly indicated; position suggested by few to several small slender processes.
Size: Intermediate to large.
Affinities:
Cordosphaeridium differs from Kleithriasphaeridium in having fibrous rather than smooth or faintly striate processes. Other genera with fibrous processes and precingular archeopyle include Amphorosphaeridium, Fibrocysta, Kenleyia, and Turbiosphaera. Amphorosphaeridium has mainly nontabular processes with only occasionally intratabular processes; Fibrocysta has a more elongate body than Cordosphaeridium and generally a larger number of paracingular processes; Kenleyia normally has fewer processes than Cordosphaeridium and they may be gonal rather than intratabular; Turbiosphaera is more elongate, its processes are typically wide and flat, and the paracingulum is represented by a shelf-like projection.