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Dissiliodinium sp. a of feist-burkhardt 1990
Dissiliodinium sp. A of Feist-Burkhardt 1990
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Genus: Dissiliodinium Drugg, 1978; emend. Bailey and Partington, 1991
tax. sr. synonym of Gongylodinium Fenton et al., 1980, according to Prauss, 1989.
possible tax. sr. synonym of Gongylodinium Fenton e al., 1980, according to Feist-Burkhardt, 1990
Type species: Dissiliodinium globulum Drugg, 1978
Original diagnosis: Drugg 1978, p.67
Cyst spherical to subspherical with a gonyaulacid epicystal paratabulation. Archaeopyle formed by loss of most of the precingular paraplates. Apical paraplates remain attached to the hypocyst via the parasulcal tongue and probably paraplate 6"" as well.
Stover and Williams 1987, p.85
Synopsis: Cysts proximate, subspherical; autophragm ornamented with features of low relief; archeopyle precingular, type 4P-5P, opercular pieces normally free; apical paraplates and probably paraplate 6" remain attached to hypocyst which lacks indications of paratabulation.
Modified description:
Shape: Subspherical.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm variously ornamented with features of low relief.
Archeopyle: Precingular, compound, type 4P-5P, formed by the loss of paraplates 1"-5" or 2"-5"; opercular pieces normally free.
Paratabulation: Indicated on epicyst only and clearly evident only when precingular paraplates are separated completely or dislodged; paraplates of apical series not differentiated and attached to hypocyst, probably together with paraplate 6", by parasulcal tongue.
Paracingulum: Generally not indicated.
Parasulcus: Not indicated.
Size: Intermediate to large, about 55 to 115 Ám.
Emended diagnosis: Bailey and Partington, 1991, p.246
Proximate subspherical gonyaulacoid dinocyst of intermediate to large size (50-110 micrometers). The autophragm is smooth, or more normally ornamented by nontabular features of low relief. The archaeopyle is variable precingular(type IP-5P),opercularpiecesnormallyfree.Apical plates and plate 6" remain attached to hypocyst. Epicystal tabulation derived from the outline of archaeopyle indicate formula; 4", 0a, 6". Faint parasutures delineating the cingulum may rarely be observed. Hypocyst lacks any indication of tabulation.
Remarks. Dissilioflinium is originally described with a type 4P-5P archaeopyle.The generic diagnosis is emended to include the variable 1P-5P archaeopyle and the absence of dorsal intercalary plates on the epicyst.
Affinities:
Drugg 1978, p.68: Dissiliodinium is related to the genera Leptodinium, Gonyaulacysta and Occisucysta. It differs from all in losing more precingular paraplates in archaeopyle formation and in lacking any obvious indication of hypocystal paratabulation.
Stover and Williams 1987, p.85: Dissiliodinium differs from Lingulodinium Wall 1967 in lacking nontabular processes. Mancodinium Morgenroth 1970 differs from Dissiliodinium in having seven rather than six precingular paraplates and in possessing anterior intercalary paraplates as well. Lunatadinium Brideaux and McIntyre 1973 is reported as having a precingular 3P archaeopyle.
Bailey and Partington, 1991, p.246: Dissiliodinium differs from Durotrigia Bailey (1987) in being non-tabulate and lacking dorsal intercalary plates on the epicyst.
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?Dissiliodinium sp. A of Feist-Burkhardt 1990
Figured in Feist-Burkhardt 1990: Pl. 3, fig. 1-3; Pl. 5, fig. 2, 4; Pl. 6 fig. 2, 3; Fig. 7
1988 Dissiliodinium sp. - LUND & ECKE, pl. 2, fig. 7, 8, 10.
Diagnosis: Feist-Burkhardt 1990, p. 617, 618
cyst proximate, subspherical. Autophragm thin, ornamented with small, regular rounded to angular, or irregular elements. Their variable size and density determines scabrate to strongly granular areas. In the strongly orna-mented zones these elements are grouped in lichen-like clusters. Archeopyle precingular, compound, type 2P - 4P, formed by the loss of the paraplates 3""-4"", 2""-4"", 3""-5"" or 2""-5"". Opercular pieces 3"" and 4"" free, 2"" and/or 5"" may be adherent. Apical paraplates remain attached to the hypocyst by a wide isthmus consisting of the paraplates 1"", 6"" and the parasulcal tongue. Paraplate 1"" may be adcingularly detached. Paraplates of the apical cap are partially differentiated. The apical cap outline suggests four apical and one intercalary paraplates. Paratabulation generally indicated only by archeopyle when precingular paraplates are separated or dislodged. Occasionally, continuous grooves (Pl. 5, fig. 2b) or alignments of granules can locally indicate the limits between paraplates. Epicystal paratabulation formula: ?pr, 4"", la, 6"" + as (Fig. 7). Precingular paraplates of unequal size and characteristic outline: 3"" with rounded posterior angles and 1"", 2"", 4"", 5"", 6"" with one, dorsally directed "stalk"-like elongate edge in adcingular position; 2"" is extremely elongate, 1"" is reduced and of a strongly asymmetrical camerate form. Paracingulum usually not expressed, sometimes indicated by a continuous groove or an alignment of granules. Parasulcus, generally not marked, can be indicated by a faint depression and a reduction in ornamentation (in SEM observation) Size range: 65 (75) 90 llm at about midlength (12 specimens measured).
Comparison: the presence of a dorsal anterior intercalary paraplate distinguishes ?Dissiliodinium sp. A from all species previously described in the genus Dissiliodinium sensu stricto . In D globulum DRUGG 1978 the isthmus connecting the apical cap with the hypocyst is formed by as and 6" only and a microreticulate ornamentation pattern may be present. D caddaense STOVER & HELBY 1987 is much bigger (95Ám in diameter) and has an antapical bulge.
Occurrence: the species is common in samples B l00/20.0, B l00/13.5 to B 100/8.5 and B 93/31.3 to B 93/23.3, Upper "Braunjura b" to Lower "Braunjura g" (=Late Aalenian, murchisonae Zone, to Early Bajocian, laeviuscula Zone) - this study.
Previously reported occurrences:
Southeast Germany: Winzer Well, 85 - 90 m (Middle to Early Bajocian) and Buchberg 3 Weii, 87 m, (Aaienian) LUND & ECKE 1988).
Northern Switzerland: Weiach corehole, Murchisonae/Concava-Schichten to Parkinsonl Schichten (Late Aalenian to Middle Bajocian), Transjurane corehole, Blaukalk "(BaJocian") - personal observation (unpublished).
Eastern France: southern Jura Mountains, Marnes Bleues (late Aalenian) - personal observation (unpublished).
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Genus: Dissiliodinium Drugg, 1978; emend. Bailey and Partington, 1991
tax. sr. synonym of Gongylodinium Fenton et al., 1980, according to Prauss, 1989.
possible tax. sr. synonym of Gongylodinium Fenton e al., 1980, according to Feist-Burkhardt, 1990
Type species: Dissiliodinium globulum Drugg, 1978
Original diagnosis: Drugg 1978, p.67
Cyst spherical to subspherical with a gonyaulacid epicystal paratabulation. Archaeopyle formed by loss of most of the precingular paraplates. Apical paraplates remain attached to the hypocyst via the parasulcal tongue and probably paraplate 6"" as well.
Stover and Williams 1987, p.85
Synopsis: Cysts proximate, subspherical; autophragm ornamented with features of low relief; archeopyle precingular, type 4P-5P, opercular pieces normally free; apical paraplates and probably paraplate 6" remain attached to hypocyst which lacks indications of paratabulation.
Modified description:
Shape: Subspherical.
Wall relationships: Autophragm only.
Wall features: No parasutural features. Autophragm variously ornamented with features of low relief.
Archeopyle: Precingular, compound, type 4P-5P, formed by the loss of paraplates 1"-5" or 2"-5"; opercular pieces normally free.
Paratabulation: Indicated on epicyst only and clearly evident only when precingular paraplates are separated completely or dislodged; paraplates of apical series not differentiated and attached to hypocyst, probably together with paraplate 6", by parasulcal tongue.
Paracingulum: Generally not indicated.
Parasulcus: Not indicated.
Size: Intermediate to large, about 55 to 115 Ám.
Emended diagnosis: Bailey and Partington, 1991, p.246
Proximate subspherical gonyaulacoid dinocyst of intermediate to large size (50-110 micrometers). The autophragm is smooth, or more normally ornamented by nontabular features of low relief. The archaeopyle is variable precingular(type IP-5P),opercularpiecesnormallyfree.Apical plates and plate 6" remain attached to hypocyst. Epicystal tabulation derived from the outline of archaeopyle indicate formula; 4", 0a, 6". Faint parasutures delineating the cingulum may rarely be observed. Hypocyst lacks any indication of tabulation.
Remarks. Dissilioflinium is originally described with a type 4P-5P archaeopyle.The generic diagnosis is emended to include the variable 1P-5P archaeopyle and the absence of dorsal intercalary plates on the epicyst.
Affinities:
Drugg 1978, p.68: Dissiliodinium is related to the genera Leptodinium, Gonyaulacysta and Occisucysta. It differs from all in losing more precingular paraplates in archaeopyle formation and in lacking any obvious indication of hypocystal paratabulation.
Stover and Williams 1987, p.85: Dissiliodinium differs from Lingulodinium Wall 1967 in lacking nontabular processes. Mancodinium Morgenroth 1970 differs from Dissiliodinium in having seven rather than six precingular paraplates and in possessing anterior intercalary paraplates as well. Lunatadinium Brideaux and McIntyre 1973 is reported as having a precingular 3P archaeopyle.
Bailey and Partington, 1991, p.246: Dissiliodinium differs from Durotrigia Bailey (1987) in being non-tabulate and lacking dorsal intercalary plates on the epicyst.
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?Dissiliodinium sp. A of Feist-Burkhardt 1990
Figured in Feist-Burkhardt 1990: Pl. 3, fig. 1-3; Pl. 5, fig. 2, 4; Pl. 6 fig. 2, 3; Fig. 7
1988 Dissiliodinium sp. - LUND & ECKE, pl. 2, fig. 7, 8, 10.
Diagnosis: Feist-Burkhardt 1990, p. 617, 618
cyst proximate, subspherical. Autophragm thin, ornamented with small, regular rounded to angular, or irregular elements. Their variable size and density determines scabrate to strongly granular areas. In the strongly orna-mented zones these elements are grouped in lichen-like clusters. Archeopyle precingular, compound, type 2P - 4P, formed by the loss of the paraplates 3""-4"", 2""-4"", 3""-5"" or 2""-5"". Opercular pieces 3"" and 4"" free, 2"" and/or 5"" may be adherent. Apical paraplates remain attached to the hypocyst by a wide isthmus consisting of the paraplates 1"", 6"" and the parasulcal tongue. Paraplate 1"" may be adcingularly detached. Paraplates of the apical cap are partially differentiated. The apical cap outline suggests four apical and one intercalary paraplates. Paratabulation generally indicated only by archeopyle when precingular paraplates are separated or dislodged. Occasionally, continuous grooves (Pl. 5, fig. 2b) or alignments of granules can locally indicate the limits between paraplates. Epicystal paratabulation formula: ?pr, 4"", la, 6"" + as (Fig. 7). Precingular paraplates of unequal size and characteristic outline: 3"" with rounded posterior angles and 1"", 2"", 4"", 5"", 6"" with one, dorsally directed "stalk"-like elongate edge in adcingular position; 2"" is extremely elongate, 1"" is reduced and of a strongly asymmetrical camerate form. Paracingulum usually not expressed, sometimes indicated by a continuous groove or an alignment of granules. Parasulcus, generally not marked, can be indicated by a faint depression and a reduction in ornamentation (in SEM observation) Size range: 65 (75) 90 llm at about midlength (12 specimens measured).
Comparison: the presence of a dorsal anterior intercalary paraplate distinguishes ?Dissiliodinium sp. A from all species previously described in the genus Dissiliodinium sensu stricto . In D globulum DRUGG 1978 the isthmus connecting the apical cap with the hypocyst is formed by as and 6" only and a microreticulate ornamentation pattern may be present. D caddaense STOVER & HELBY 1987 is much bigger (95Ám in diameter) and has an antapical bulge.
Occurrence: the species is common in samples B l00/20.0, B l00/13.5 to B 100/8.5 and B 93/31.3 to B 93/23.3, Upper "Braunjura b" to Lower "Braunjura g" (=Late Aalenian, murchisonae Zone, to Early Bajocian, laeviuscula Zone) - this study.
Previously reported occurrences:
Southeast Germany: Winzer Well, 85 - 90 m (Middle to Early Bajocian) and Buchberg 3 Weii, 87 m, (Aaienian) LUND & ECKE 1988).
Northern Switzerland: Weiach corehole, Murchisonae/Concava-Schichten to Parkinsonl Schichten (Late Aalenian to Middle Bajocian), Transjurane corehole, Blaukalk "(BaJocian") - personal observation (unpublished).
Eastern France: southern Jura Mountains, Marnes Bleues (late Aalenian) - personal observation (unpublished).
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