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Druggidium
From Fensome et al., 2019:
Druggidium, Habib, 1973, p.49,51.
Emendation: Harding, 1986b, p.18–19.
Taxonomic senior synonym: Raphidodinium, according to Below (1987b, p.57) -- however, Lentin and Williams (1989, p.121) retained
Druggidium.
Type: Habib, 1973, pl.1, fig.3; text-fig.3, as Druggidium apicopaucicum.
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Original description: [Habib, 1973]:
Description:
Small proximate dinoflagellate cysts with oval to elliptical outline in dorsoventral view and cucumiform to oval to elliptical in lateral and oblique views; average width/length ratio (W.L.R.) varies from 0.65 to 0.81. Epitract semicircular to subtriangular in outline and small; hypotract long and asymmetrically subrounded or subangular at antapex; average cingulum index (C.l.) ranges from 21 to 27 (for measurement of cingulum index, see Evitt et al. [1967]). Discrete apical and antapical horns are lacking. Cingulum laevorotary to helicoid, but not displaced more than one cingulum width. Cyst tabulation well expressed or obscured and incomplete; it is formed as smooth-straight, sinuous, or distinctly crenulated ridges or septa that may be smooth, radially striate, perforate, or expressed partly as discrete verrucae; plate formula 3` or 4` 0a, 6", 6c, 6```, 1p, 1````. Sulcus variable; commonly spatulate and with sulcal (s`) and anterior sulcal. (as) platelets extending to epitract. Archeopyle complex precingular; formed by loss of cyst plates 2" and 3". Operculum constructed of two opercular pieces that are adherent at the cingulum in the majority of examples (2P). Tract surface smooth to scabrate, microgranulate, alveolate, or with raised microreticulate membrane supported by short, distally recurving baculae. Maximum diameter of known examples not greater than 44 microns.
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Modified description:
Stover and Evitt, 1978, p. 152-153:
Synopsis:
Cysts proximochorate, subspherical to elongate ellipsoidal; epicyst typically shorter than hypocyst; paratabulation gonyaulacacean, indicated by parasutural ridges; archeopyle precingular, Type 2Pa (2" + 3").
Description:
Shape: Subspherical to elongate ellipsoidal, generally the latter; epicyst much shorter than hypocyst.
Wall relationships: Generally autophragm only; autophragm and ectophragm present on one species.
Wall features: Parasutural ridges straight or crenulate and smooth, striate, or perforate. Autophragm smooth, scabrate, microreticulate, alveolate or baculate; ectophragm microreticulate.
Paratabulation: Indicated by parasutural features; gonyaulacacean, formula: 3`-4`, 6", 6c, 6```, 1p, 1````, 0-3s.
Archeopyle: Precingular, Type 2Pa; opercular pieces (paraplates 2" + 3") generally attached antapically.
Paracingulum: Indicated by six paraplates, rectangular and square in outline; paracingulum nearer the apical than the antapical end.
Parasulcus: Outline variable, commonly spatulate; mainly on the hypocyst, but narrow shorter portion extends onto the epicyst; constituent paraplates may be discernible.
Size: Small.
Affinities:
Druggidium differs from Microdinium in having a precingular rather than an apical archeopyle. It differs from Impagidinium in having the paracingulum nearer the apical than the antapical end, in having a Type 2P rather than a simple Type P archeopyle, and in being generally more elongate.
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Partially emended diagnosis Harding, 1986b:
The genus is emended to incorporate the paratabulation formula as revised by Habib (Habib & Drugg, 1983) for D. apicopaucinum and observed by the present author on D. jubatum and D. augustum sp. nov. The formula is -pr, 4', 4a, 7'', 7c, 6''', 1p, 1'''', 2s (in kofoidian notation: for Taylor-Evitt comparisons see text-Figs. 1-3). The emendation also stresses the variable nature of the archeopyle structure within the genus. The following archaeopyle types have so far beenb observed within the genus:
(i) Type P
(ii) Type 2P - compound biplacoid operculum; both pieces adherent adcingularly
(iii) Type 2P - compound biplacoid operculum; 3"[4i] adapically adherent, 4''[4u] free.
(iv) Type 2P - compound biplacoid operculum; both pieces free
(v) Type (AI)a2Pa
(vi) Type (AI)2Pa
remarks: evidence upon SEM observations of this genus reveal the presence of distinct anterior intercalaries associated with seven precingular paraplates. Thus, the genus should be places in the Microdinium complex of Gp-cysts rather than the Phanerodinium complex(Evitt, 1985, p. 215. The transferals of Phanerodinium f ourmarierii Lejeune-Carpentier and P. laeve Lejeune-Carpentier to Druggidium (Lejeune-Carpentier & Sarjeant, 1983) are questionable. P. laeve is a species based on one very poorly known specimen. The diagnostic apical and ventral areas are not visible in the flint matrix and the specimen displays no archaeopyle. The paratabulation formula indicates no anterior intercalaries, a feature now known to characterise the genus. It is recommended that P. laeve is retained in Phanerodinium and the species name suppressed, being used to refer only to the holotype.
The characters displayed by Phanerodinium fourmarierii do not unequivocally argue for a transferral to Druggidium. The arrangement of the apical paraplates on the paratype is clearly dissimilar to that now known for the latter genus as it possesses only one anterior intercalary paraplate and a much reduced second precingular. The ventral paratabulation of this species is also poorly known, a posterior intercalary paraplate was "presumed but could not be confirmed" (Lejeune-Carpentier & Sarjeant, 1983, p. 3). Thus P. fourmarierii should be retained in Phanerodinium until more details of its paratabulation are known. In addition to the above differences, it is of importance to note that all of the positively identified species of Druggidium are restricted to the pre-Aptian Early Cretaceous whereas P. fourmarierii and P. laeve were described from the Senonian. The present state of knowledge indicates that this genus is of excellent stratigraphic value, the individual species being of restricted range and of moderate abundance.
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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.
Druggidium Habib, 1973, emend. Harding, 1986b. According to Harding (1986), this genus can have the following archeopyle types: type P, type 2P, compound biplacoid operculum, both pieces adherent cingularly, type 2P, compound biplacoid operculum: 3" adapically adherent, 4" free, type 2P compound, biplacoid operculum, both pieces free, type (AI)a2Pa, type (AI)2Pa Plate formula is pr, 4`, 4a, 7", 7c, 6"\ , 1p, 1", 2s.
Druggidium, Habib, 1973, p.49,51.
Emendation: Harding, 1986b, p.18–19.
Taxonomic senior synonym: Raphidodinium, according to Below (1987b, p.57) -- however, Lentin and Williams (1989, p.121) retained
Druggidium.
Type: Habib, 1973, pl.1, fig.3; text-fig.3, as Druggidium apicopaucicum.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Habib, 1973]:
Description:
Small proximate dinoflagellate cysts with oval to elliptical outline in dorsoventral view and cucumiform to oval to elliptical in lateral and oblique views; average width/length ratio (W.L.R.) varies from 0.65 to 0.81. Epitract semicircular to subtriangular in outline and small; hypotract long and asymmetrically subrounded or subangular at antapex; average cingulum index (C.l.) ranges from 21 to 27 (for measurement of cingulum index, see Evitt et al. [1967]). Discrete apical and antapical horns are lacking. Cingulum laevorotary to helicoid, but not displaced more than one cingulum width. Cyst tabulation well expressed or obscured and incomplete; it is formed as smooth-straight, sinuous, or distinctly crenulated ridges or septa that may be smooth, radially striate, perforate, or expressed partly as discrete verrucae; plate formula 3` or 4` 0a, 6", 6c, 6```, 1p, 1````. Sulcus variable; commonly spatulate and with sulcal (s`) and anterior sulcal. (as) platelets extending to epitract. Archeopyle complex precingular; formed by loss of cyst plates 2" and 3". Operculum constructed of two opercular pieces that are adherent at the cingulum in the majority of examples (2P). Tract surface smooth to scabrate, microgranulate, alveolate, or with raised microreticulate membrane supported by short, distally recurving baculae. Maximum diameter of known examples not greater than 44 microns.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt, 1978, p. 152-153:
Synopsis:
Cysts proximochorate, subspherical to elongate ellipsoidal; epicyst typically shorter than hypocyst; paratabulation gonyaulacacean, indicated by parasutural ridges; archeopyle precingular, Type 2Pa (2" + 3").
Description:
Shape: Subspherical to elongate ellipsoidal, generally the latter; epicyst much shorter than hypocyst.
Wall relationships: Generally autophragm only; autophragm and ectophragm present on one species.
Wall features: Parasutural ridges straight or crenulate and smooth, striate, or perforate. Autophragm smooth, scabrate, microreticulate, alveolate or baculate; ectophragm microreticulate.
Paratabulation: Indicated by parasutural features; gonyaulacacean, formula: 3`-4`, 6", 6c, 6```, 1p, 1````, 0-3s.
Archeopyle: Precingular, Type 2Pa; opercular pieces (paraplates 2" + 3") generally attached antapically.
Paracingulum: Indicated by six paraplates, rectangular and square in outline; paracingulum nearer the apical than the antapical end.
Parasulcus: Outline variable, commonly spatulate; mainly on the hypocyst, but narrow shorter portion extends onto the epicyst; constituent paraplates may be discernible.
Size: Small.
Affinities:
Druggidium differs from Microdinium in having a precingular rather than an apical archeopyle. It differs from Impagidinium in having the paracingulum nearer the apical than the antapical end, in having a Type 2P rather than a simple Type P archeopyle, and in being generally more elongate.
-------------------------------------------------
Partially emended diagnosis Harding, 1986b:
The genus is emended to incorporate the paratabulation formula as revised by Habib (Habib & Drugg, 1983) for D. apicopaucinum and observed by the present author on D. jubatum and D. augustum sp. nov. The formula is -pr, 4', 4a, 7'', 7c, 6''', 1p, 1'''', 2s (in kofoidian notation: for Taylor-Evitt comparisons see text-Figs. 1-3). The emendation also stresses the variable nature of the archeopyle structure within the genus. The following archaeopyle types have so far beenb observed within the genus:
(i) Type P
(ii) Type 2P - compound biplacoid operculum; both pieces adherent adcingularly
(iii) Type 2P - compound biplacoid operculum; 3"[4i] adapically adherent, 4''[4u] free.
(iv) Type 2P - compound biplacoid operculum; both pieces free
(v) Type (AI)a2Pa
(vi) Type (AI)2Pa
remarks: evidence upon SEM observations of this genus reveal the presence of distinct anterior intercalaries associated with seven precingular paraplates. Thus, the genus should be places in the Microdinium complex of Gp-cysts rather than the Phanerodinium complex(Evitt, 1985, p. 215. The transferals of Phanerodinium f ourmarierii Lejeune-Carpentier and P. laeve Lejeune-Carpentier to Druggidium (Lejeune-Carpentier & Sarjeant, 1983) are questionable. P. laeve is a species based on one very poorly known specimen. The diagnostic apical and ventral areas are not visible in the flint matrix and the specimen displays no archaeopyle. The paratabulation formula indicates no anterior intercalaries, a feature now known to characterise the genus. It is recommended that P. laeve is retained in Phanerodinium and the species name suppressed, being used to refer only to the holotype.
The characters displayed by Phanerodinium fourmarierii do not unequivocally argue for a transferral to Druggidium. The arrangement of the apical paraplates on the paratype is clearly dissimilar to that now known for the latter genus as it possesses only one anterior intercalary paraplate and a much reduced second precingular. The ventral paratabulation of this species is also poorly known, a posterior intercalary paraplate was "presumed but could not be confirmed" (Lejeune-Carpentier & Sarjeant, 1983, p. 3). Thus P. fourmarierii should be retained in Phanerodinium until more details of its paratabulation are known. In addition to the above differences, it is of importance to note that all of the positively identified species of Druggidium are restricted to the pre-Aptian Early Cretaceous whereas P. fourmarierii and P. laeve were described from the Senonian. The present state of knowledge indicates that this genus is of excellent stratigraphic value, the individual species being of restricted range and of moderate abundance.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Druggidium Habib, 1973, emend. Harding, 1986b. According to Harding (1986), this genus can have the following archeopyle types: type P, type 2P, compound biplacoid operculum, both pieces adherent cingularly, type 2P, compound biplacoid operculum: 3" adapically adherent, 4" free, type 2P compound, biplacoid operculum, both pieces free, type (AI)a2Pa, type (AI)2Pa Plate formula is pr, 4`, 4a, 7", 7c, 6"\ , 1p, 1", 2s.