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Caligodinium
From Williams et al., 2017:
[Caligodinium, Drugg, 1970b, p. 814-815; Emendation: Manum and Williams, 1995, p. 185.
Type species: Caligodinium amiculum, Drugg, 1970 (1970b, fig.9A)]
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Original description: [Drugg, 1970]:
Description:
Tract ellipsoidal with an apical archeopyle. The operculum consists of three plates. One plate is relatively large, more or less ellipsoidal in outline and bears a sulcal tongue. The other two plates are smaller and elongate. The tract is surrounded by a flocculent porous material.
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Modified descriptions:
Stover and Evitt, 1978, p. 23-24:
Diagnosis:
Cysts proximate, subspherical to ellipsoidal, with or without surrounding flocculent material, and without moderately to strongly elevated features; archeopyle apical and atypical, operculum composed of three paraplates.
Description:
Shape: Subspherical to ellipsoidal.
Wall relationships: Autophragm only; flocculent outer covering loosely adherent and not regarded as a constituent wall layer.
Wall features: No parasutural features. Autophragm finely punctate or smooth.
Paratabulation: Indicated by archeopyle only.
Archeopyle: Apical; operculum free or more commonly dislodged slightly, composed of one relatively large and two smaller paraplates; principal archeopyle suture irregularly angular.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Dimensions: Intermediate.
Affinities:
Caligodinium differs from Leberidocysta in having an apical archeopyle whose operculum consists of one large and two small separated pieces of unusual shapes. Apical archeopyle on Leberidocysta is the typical Type (tA), with a one-piece operculum. D. Wall (pers. comm.) favors the interpretation that the archeopyle on Caligodinium way be antapical rather than apical and comparable to the archeopyle on Tuberculodinium (or Pyrophacus), provided certain modifications are taken into account. Wiggins (1972), however, interprets the archeopyle of Caligodinium as intercalary but fails to present reasons for doing so.
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Biffi and Manum, 1988, p. 178:
Remarks:
When describing this genus and its type species, Drugg lacked evidence to suggest the paratabulation, except for the trioperculate, apical nature of the archeopyle. Wall & Dale (1971, p. 231) subsequently stressed the absence of features that could indicate the orientation in these cysts and implied an antapical archeopyle by suggesting a similarity with Pyrophacus horologium particularly on the strength of the presence of a flocculent outer covering (cf. also comment in Stover & Evitt 1978, p. 24).
Lentin & Williams (1973, p. 21), on the other hand, maintained Drugg`s interpretation of the archeopyle being apical when formally transferring Kalyptea aceras Manum & Cookson (1964) to Caligodinium, thus accepting Drugg`s original indications of a generally close resemblance between Kalyptea aceras and C. amiculum.
The cyst described as C. pychnum n. sp. could only be referred with confidence to this genus after examination of the holotype for C. amiculum. In the holotype, the operculum is not altogether easy to interpret because of the partly superimposed operculum pieces and the additional obstruction to vision caused by the flocculent covering. However, the interpretation proposed below for C. pychnum can also be applied to C. amiculum as shown by Drugg`s original illustrations reproduced here with our notation (Text-figs. 10-11). The interpretation presented here does not in our view require a formal emendation of the genus, and Stover & Evitt`s (1978, p. 23) synopsis is still adequate.
The only other species so far attributed to Caligodinium is C. aceras (Manum & Cookson) Lentin & Williams, as already mentioned above. Reexamination of the originals (Manum & Cookson 1964, Pl. VI, Figs. 10,11 and 12) could not demonstrate the trioperculate archeopyle, typical of the genus. However, the operculum shows accessory sutures and a tendency towards breaking up, indicating an intermediate condition, between a single-piece and a three-piece operculum. The attribution of this species to Caligodinium therefore appears quite acceptable.
[Caligodinium, Drugg, 1970b, p. 814-815; Emendation: Manum and Williams, 1995, p. 185.
Type species: Caligodinium amiculum, Drugg, 1970 (1970b, fig.9A)]
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Original description: [Drugg, 1970]:
Description:
Tract ellipsoidal with an apical archeopyle. The operculum consists of three plates. One plate is relatively large, more or less ellipsoidal in outline and bears a sulcal tongue. The other two plates are smaller and elongate. The tract is surrounded by a flocculent porous material.
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Modified descriptions:
Stover and Evitt, 1978, p. 23-24:
Diagnosis:
Cysts proximate, subspherical to ellipsoidal, with or without surrounding flocculent material, and without moderately to strongly elevated features; archeopyle apical and atypical, operculum composed of three paraplates.
Description:
Shape: Subspherical to ellipsoidal.
Wall relationships: Autophragm only; flocculent outer covering loosely adherent and not regarded as a constituent wall layer.
Wall features: No parasutural features. Autophragm finely punctate or smooth.
Paratabulation: Indicated by archeopyle only.
Archeopyle: Apical; operculum free or more commonly dislodged slightly, composed of one relatively large and two smaller paraplates; principal archeopyle suture irregularly angular.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Dimensions: Intermediate.
Affinities:
Caligodinium differs from Leberidocysta in having an apical archeopyle whose operculum consists of one large and two small separated pieces of unusual shapes. Apical archeopyle on Leberidocysta is the typical Type (tA), with a one-piece operculum. D. Wall (pers. comm.) favors the interpretation that the archeopyle on Caligodinium way be antapical rather than apical and comparable to the archeopyle on Tuberculodinium (or Pyrophacus), provided certain modifications are taken into account. Wiggins (1972), however, interprets the archeopyle of Caligodinium as intercalary but fails to present reasons for doing so.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Biffi and Manum, 1988, p. 178:
Remarks:
When describing this genus and its type species, Drugg lacked evidence to suggest the paratabulation, except for the trioperculate, apical nature of the archeopyle. Wall & Dale (1971, p. 231) subsequently stressed the absence of features that could indicate the orientation in these cysts and implied an antapical archeopyle by suggesting a similarity with Pyrophacus horologium particularly on the strength of the presence of a flocculent outer covering (cf. also comment in Stover & Evitt 1978, p. 24).
Lentin & Williams (1973, p. 21), on the other hand, maintained Drugg`s interpretation of the archeopyle being apical when formally transferring Kalyptea aceras Manum & Cookson (1964) to Caligodinium, thus accepting Drugg`s original indications of a generally close resemblance between Kalyptea aceras and C. amiculum.
The cyst described as C. pychnum n. sp. could only be referred with confidence to this genus after examination of the holotype for C. amiculum. In the holotype, the operculum is not altogether easy to interpret because of the partly superimposed operculum pieces and the additional obstruction to vision caused by the flocculent covering. However, the interpretation proposed below for C. pychnum can also be applied to C. amiculum as shown by Drugg`s original illustrations reproduced here with our notation (Text-figs. 10-11). The interpretation presented here does not in our view require a formal emendation of the genus, and Stover & Evitt`s (1978, p. 23) synopsis is still adequate.
The only other species so far attributed to Caligodinium is C. aceras (Manum & Cookson) Lentin & Williams, as already mentioned above. Reexamination of the originals (Manum & Cookson 1964, Pl. VI, Figs. 10,11 and 12) could not demonstrate the trioperculate archeopyle, typical of the genus. However, the operculum shows accessory sutures and a tendency towards breaking up, indicating an intermediate condition, between a single-piece and a three-piece operculum. The attribution of this species to Caligodinium therefore appears quite acceptable.