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Canningia
From Williams et al., 2017:
[Canningia, Cookson and Eisenack, 1960, p. 251; Emendations: Cookson and Eisenack 1961; Dörhöfer and Davies, 1980, p. 36; Below, 1981a, p. 30; Helby, 1987, p. 321-322
tax. sr. syn. of Circulodinium Alberti, 1961, according to Millioud, 1969. Jansonius, 1986, and Helby, 1987, retained Circulodinium as a separate genus.
Type species: Canningia reticulata, Cookson and Eisenack, 1960b (pl.38, fig.1)] , emend. Below, 1981; emend. Helby, 1987
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Original description: [Cookson and Eisenack, 1960]:
Description:
Shell flattened, roughly four-sided to almost circular with a slight apical prominence and a broadly indented base. The basal projections (corresponding to antapical horns) are either equal or unequal and frequently differ slightly in shape. An equatorial girdle is either absent or faintly indicated both on the surface or by reentrant angles at the sides. The shell opens by a proximal break which results in the complete detachment of the apical region.
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Modified description:
Stover and Evitt, 1978, p. 24
Synopsis: Cysts proximate, lenticular, with slight apical prominence and two antapical lobations; autophragm variously ornamented; ornamentation uniformly distributed, consisting of spines or processes of low to moderate relief; archeopyle apical, Type tA; parasulcal notch offset.
Description:
Shape: Lenticular; apical margin may be obtusely angular and antapical margin may have two subangular lobations.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm variously ornamented (scabrate to retirugulate), ornamentation uniformly distributed and of low to moderate relief; surface without spines or processes.
Paratabulation: Indicated by archeopyle only, or by archeopyle and paracingulum.
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag with offset parasulcal notch; operculum free.
Paracingulum: Not indicated, or expressed faintly by small protrusions along the lateral margins at about midlength.
Parasulcus: Not indicated.
Size: Small to large.
Affinities:
Canningia differs from Cyclonephelium in being uniformly ornamented, whereas on Cyclonephelium the ornamentation is generally lacking or reduced in the midventral and middorsal areas. In addition, the ornamentation on Canningia tends to be less discrete and lower than on typical forms of Cyclonephelium. Canningia differs from Canninginopsis in lacking parasutural features.
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Emended descriptions:
Dörhöfer and Davies, 1980
Description:
Proximate dinoflagellate cyst with roughly five-sided to circular outline. Apex prominent, antapex broadly indented between two rounded antapical horns. Cingulum occasionally indicated by faint surface ornamentation and/or slight bulges representing postcingular horns. Surface smooth or with low but variable ornament. Archaeopyle (AI), formed along an asymmetrical zigzag suture line. Tabulation was not determined. Some species presently in Canningia do not exhibit the (AI) archaeopyle and are omitted from the genus. Their archaeopyle suture is symmetrical and the antapex founded.
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Below, 1981: (Translation: LPP)
Diagnosis:
Spheroidal to lenticular cyst of round to pentagonal shape. Apex rounded or with low apical bulge. Antapex rounded, flattened or with lobus. Cyst wall two layered. Periphragm smooth or ornamented. Endocyst towards inner cyst smooth. Between both membranes variously structured ?endopragmal filling. Surface rarely divided in paraplates of gonyaulacoid scheme, usually undivided. Paracingulum and parasulcus into cyst indented or missing. Archeopyle apical, Type "Aa". Operculum simple, attached or enlarged.
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Remark: Hedlund and Norris, 1986, did not accept the emendation by Below, 1981.
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Helby, 1987
Description:
Shape: Lenticular cyst, apicalmargin obtusely angular, antapical margin modified by two subangular, unequal lobes. Small lateral protrusions may mark paracingulum.
Wall features: Two layered, holocavate autophragm bearing processes varying in size, density and distribution, generally nontabular, less frequently penitabular or parasutural. Ectophragm usually reticulate, varying to rugoreticulate; occasionally, finely granulate or smooth.
Paratabulation: Indicated by archaeopyle and variably expressed parasutural features.
Archaeopyle: Apical, type (tA); principal archaeopyle suture zigzag with offset parasutural notch. Operculum usually free.
Paracingulum: Usually indicated by protrusion of parasutural ridges across dorsal surface, most evident at equator.
Parasulcus: Usually marked by absence or reduction in length of processes between wall layers. Where observed, parasulcus usually slightly sinuous moving from left ventral position on the epicyst to midventral position on the hypocyst.
Size: Small to large.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Canningia Cookson and Eisenack, 1960b, emend. Helby, 1987. According to Helby (1987, p.322), this species has a lenticular body, subpentagonal in outline, two-layered and with or without indications of paratabulation. The autophragm bears processes of variable size, which may be nontabular, less frequently penitabular or parasutural. The ectophragm is usually reticulate, varying to rugo-reticulate, occasionally finely granular or smooth.
[Canningia, Cookson and Eisenack, 1960, p. 251; Emendations: Cookson and Eisenack 1961; Dörhöfer and Davies, 1980, p. 36; Below, 1981a, p. 30; Helby, 1987, p. 321-322
tax. sr. syn. of Circulodinium Alberti, 1961, according to Millioud, 1969. Jansonius, 1986, and Helby, 1987, retained Circulodinium as a separate genus.
Type species: Canningia reticulata, Cookson and Eisenack, 1960b (pl.38, fig.1)] , emend. Below, 1981; emend. Helby, 1987
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Original description: [Cookson and Eisenack, 1960]:
Description:
Shell flattened, roughly four-sided to almost circular with a slight apical prominence and a broadly indented base. The basal projections (corresponding to antapical horns) are either equal or unequal and frequently differ slightly in shape. An equatorial girdle is either absent or faintly indicated both on the surface or by reentrant angles at the sides. The shell opens by a proximal break which results in the complete detachment of the apical region.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt, 1978, p. 24
Synopsis: Cysts proximate, lenticular, with slight apical prominence and two antapical lobations; autophragm variously ornamented; ornamentation uniformly distributed, consisting of spines or processes of low to moderate relief; archeopyle apical, Type tA; parasulcal notch offset.
Description:
Shape: Lenticular; apical margin may be obtusely angular and antapical margin may have two subangular lobations.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm variously ornamented (scabrate to retirugulate), ornamentation uniformly distributed and of low to moderate relief; surface without spines or processes.
Paratabulation: Indicated by archeopyle only, or by archeopyle and paracingulum.
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag with offset parasulcal notch; operculum free.
Paracingulum: Not indicated, or expressed faintly by small protrusions along the lateral margins at about midlength.
Parasulcus: Not indicated.
Size: Small to large.
Affinities:
Canningia differs from Cyclonephelium in being uniformly ornamented, whereas on Cyclonephelium the ornamentation is generally lacking or reduced in the midventral and middorsal areas. In addition, the ornamentation on Canningia tends to be less discrete and lower than on typical forms of Cyclonephelium. Canningia differs from Canninginopsis in lacking parasutural features.
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Emended descriptions:
Dörhöfer and Davies, 1980
Description:
Proximate dinoflagellate cyst with roughly five-sided to circular outline. Apex prominent, antapex broadly indented between two rounded antapical horns. Cingulum occasionally indicated by faint surface ornamentation and/or slight bulges representing postcingular horns. Surface smooth or with low but variable ornament. Archaeopyle (AI), formed along an asymmetrical zigzag suture line. Tabulation was not determined. Some species presently in Canningia do not exhibit the (AI) archaeopyle and are omitted from the genus. Their archaeopyle suture is symmetrical and the antapex founded.
----------------------------------------
Below, 1981: (Translation: LPP)
Diagnosis:
Spheroidal to lenticular cyst of round to pentagonal shape. Apex rounded or with low apical bulge. Antapex rounded, flattened or with lobus. Cyst wall two layered. Periphragm smooth or ornamented. Endocyst towards inner cyst smooth. Between both membranes variously structured ?endopragmal filling. Surface rarely divided in paraplates of gonyaulacoid scheme, usually undivided. Paracingulum and parasulcus into cyst indented or missing. Archeopyle apical, Type "Aa". Operculum simple, attached or enlarged.
------------
Remark: Hedlund and Norris, 1986, did not accept the emendation by Below, 1981.
----------------------------------------
Helby, 1987
Description:
Shape: Lenticular cyst, apicalmargin obtusely angular, antapical margin modified by two subangular, unequal lobes. Small lateral protrusions may mark paracingulum.
Wall features: Two layered, holocavate autophragm bearing processes varying in size, density and distribution, generally nontabular, less frequently penitabular or parasutural. Ectophragm usually reticulate, varying to rugoreticulate; occasionally, finely granulate or smooth.
Paratabulation: Indicated by archaeopyle and variably expressed parasutural features.
Archaeopyle: Apical, type (tA); principal archaeopyle suture zigzag with offset parasutural notch. Operculum usually free.
Paracingulum: Usually indicated by protrusion of parasutural ridges across dorsal surface, most evident at equator.
Parasulcus: Usually marked by absence or reduction in length of processes between wall layers. Where observed, parasulcus usually slightly sinuous moving from left ventral position on the epicyst to midventral position on the hypocyst.
Size: Small to large.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Canningia Cookson and Eisenack, 1960b, emend. Helby, 1987. According to Helby (1987, p.322), this species has a lenticular body, subpentagonal in outline, two-layered and with or without indications of paratabulation. The autophragm bears processes of variable size, which may be nontabular, less frequently penitabular or parasutural. The ectophragm is usually reticulate, varying to rugo-reticulate, occasionally finely granular or smooth.