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Weiachia fenestrata
Weiachia fenestrata Feist-Burkhardt 1995b
Holotype Feist-Burkhardt 1995b: Plate 1, fig. 9, Text-Figure 3).
Locus typicus: Jurensismergel, north Switzerland, Weiach corehole, depth 669.54 m
Stratum ypicum: late Toarcian, Thouarsense Zone (sample SF 182).
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Weiachia fenestrata Feist-Burkhardt, 1995b. Diagnosis from Feist-Burkhardt (1995b, p.213-214), proximate dinoflagellate cysts, dorso-ventrally flattened, cavate with large pericoel. Pericyst subpentagonal, endocyst of peridinioid shape. Endo- and pericyst with tapered apices. Peri- and endophragm thin, endophragm slightly thicker, both layers are psilate to scabrate. Periphragm with fenestrae in apical, anterior intercalary, precingular and postcingular positions. Endoarcheopyle intercalary, type I@, operculum (paraplate 2a) camerate, adnate to the precingular paraplates. Periarcheopyle not observed. Paratabulation on endocyst generally indicated by archeopyle only; apex on endocyst marked by an oval ring-like structure, corresponding probably to the pop paraplate. Paratabulation on pericyst indicated by fenestrae corresponding to the paraplates of apical, intercalary, precingular and postcingular series. Endocingulum marked by a large indentation of the endocyst. Pericingulum not expressed or indicated by transversal folds in periphragm. Parasulcus generally not expressed, except for flagellar pore imprint. Size: pericyst length 29-39 µm, width 24-31 µm, endocyst length 26-32 µm, width 18-23 µm.
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Description: Feist-Burkhardt 1995b, p. 213-214
Proximate dinoflagellate cysts, dorso-ventrally flattened, cavate with large pericoel. Pericyst subpentagonal, endocyst of peridinioid shape. Endo- and pericyst with tapered apices. Peri- and endophragm thin, endophragm slightly thicker, both layers are psilate to scabrate. Periphragm with fenestrae in apical, anterior intercalary, precingular and postcingular positions. Endoarcheopyle intercalary, type Ia, operculum (paraplate 2a) camerate, adnate to the precingular paraplates. Periarcheopyle not observed. Paratabulation on endocyst generally indicated by archeopyle only; apex on endocyst marked by an oval ring-like structure, corresponding probably to the pop paraplate (Plate 1, fig.6). Paratabulation on pericyst indicated by fenestrae corresponding to the paraplatesofapical,intercalary,precingularandpostcingular series. Endocingulum marked by a large indentation of the endocyst. Pericingulum not expressed or indicated by transversal folds in periphragm. Parasulcus generally not expressed, except for flagellar pore imprint.
Size. Holotype: Pericyst: length 39 µm, width 31 µm. Endocyst: length 32 µm, width 23 µm. Size Range. Pericyst: length 29 µm - 39 µm, width 24 µm - 31 µm. Endocyst: length 26 µm - 32 µm, width 18 µm - 23 µm. Material. 14 specimens, 3 measured.
Remarks: Feist-Burkhardt 1995b, p. 213-214
Fenestrae are most clearly visible when a wide pericoel is developed. In areas where the periphragm lies on the endophragm, depending on specimen orientation, visual differentiation of the two wall layers, and therefore recognition of fenestrae, is difficult. In the holotype (Plate I, fig.9, Text-Figure 3), at least two apical, two precingular, and three postcingular fenestrae are unequivocally present. Additionally, three precingular fenestrae below the archeopyle, and one anterior intercalary fenestra to the right of the archeopyle may be discernible, leading to the paratabulation interpretation given in Text-Figure 3. This paratabulation pattern is consistent with that given for "Glaucod inium pumil um" from the upper Toarci an of south-west Germany (Wille, 1982, p. 76, text-fig. 1) and Moesiodinium vozzhennikovae Below 1987 from the upper Volgian of the former Soviet Union (Below 1987, p. 130, text-fig.69). The paratabulation formula herein tentatively proposed for Weiachia fenestrata - xpr, 5', 3a, 7", xc, 5"', 2"", xs - is based on the interpretation of these two genera, which are considered to be closely related to the new genus.
Comparison: Feist-Burkhardt 1995b, p. 213-214
Weiachia fenestrata differs from other species of the genus in having an endocyst with aperidinioid shape, and consistently present fenestrae. It differs from speciesbelongingto Moesiodinium Antones,cu 1974 emend. Below 1987 in having an adnate rather than free operculum. Occurrence. Late Toarcian, Thouarsense Zone, Switzerland.
Holotype Feist-Burkhardt 1995b: Plate 1, fig. 9, Text-Figure 3).
Locus typicus: Jurensismergel, north Switzerland, Weiach corehole, depth 669.54 m
Stratum ypicum: late Toarcian, Thouarsense Zone (sample SF 182).
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Weiachia fenestrata Feist-Burkhardt, 1995b. Diagnosis from Feist-Burkhardt (1995b, p.213-214), proximate dinoflagellate cysts, dorso-ventrally flattened, cavate with large pericoel. Pericyst subpentagonal, endocyst of peridinioid shape. Endo- and pericyst with tapered apices. Peri- and endophragm thin, endophragm slightly thicker, both layers are psilate to scabrate. Periphragm with fenestrae in apical, anterior intercalary, precingular and postcingular positions. Endoarcheopyle intercalary, type I@, operculum (paraplate 2a) camerate, adnate to the precingular paraplates. Periarcheopyle not observed. Paratabulation on endocyst generally indicated by archeopyle only; apex on endocyst marked by an oval ring-like structure, corresponding probably to the pop paraplate. Paratabulation on pericyst indicated by fenestrae corresponding to the paraplates of apical, intercalary, precingular and postcingular series. Endocingulum marked by a large indentation of the endocyst. Pericingulum not expressed or indicated by transversal folds in periphragm. Parasulcus generally not expressed, except for flagellar pore imprint. Size: pericyst length 29-39 µm, width 24-31 µm, endocyst length 26-32 µm, width 18-23 µm.
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Description: Feist-Burkhardt 1995b, p. 213-214
Proximate dinoflagellate cysts, dorso-ventrally flattened, cavate with large pericoel. Pericyst subpentagonal, endocyst of peridinioid shape. Endo- and pericyst with tapered apices. Peri- and endophragm thin, endophragm slightly thicker, both layers are psilate to scabrate. Periphragm with fenestrae in apical, anterior intercalary, precingular and postcingular positions. Endoarcheopyle intercalary, type Ia, operculum (paraplate 2a) camerate, adnate to the precingular paraplates. Periarcheopyle not observed. Paratabulation on endocyst generally indicated by archeopyle only; apex on endocyst marked by an oval ring-like structure, corresponding probably to the pop paraplate (Plate 1, fig.6). Paratabulation on pericyst indicated by fenestrae corresponding to the paraplatesofapical,intercalary,precingularandpostcingular series. Endocingulum marked by a large indentation of the endocyst. Pericingulum not expressed or indicated by transversal folds in periphragm. Parasulcus generally not expressed, except for flagellar pore imprint.
Size. Holotype: Pericyst: length 39 µm, width 31 µm. Endocyst: length 32 µm, width 23 µm. Size Range. Pericyst: length 29 µm - 39 µm, width 24 µm - 31 µm. Endocyst: length 26 µm - 32 µm, width 18 µm - 23 µm. Material. 14 specimens, 3 measured.
Remarks: Feist-Burkhardt 1995b, p. 213-214
Fenestrae are most clearly visible when a wide pericoel is developed. In areas where the periphragm lies on the endophragm, depending on specimen orientation, visual differentiation of the two wall layers, and therefore recognition of fenestrae, is difficult. In the holotype (Plate I, fig.9, Text-Figure 3), at least two apical, two precingular, and three postcingular fenestrae are unequivocally present. Additionally, three precingular fenestrae below the archeopyle, and one anterior intercalary fenestra to the right of the archeopyle may be discernible, leading to the paratabulation interpretation given in Text-Figure 3. This paratabulation pattern is consistent with that given for "Glaucod inium pumil um" from the upper Toarci an of south-west Germany (Wille, 1982, p. 76, text-fig. 1) and Moesiodinium vozzhennikovae Below 1987 from the upper Volgian of the former Soviet Union (Below 1987, p. 130, text-fig.69). The paratabulation formula herein tentatively proposed for Weiachia fenestrata - xpr, 5', 3a, 7", xc, 5"', 2"", xs - is based on the interpretation of these two genera, which are considered to be closely related to the new genus.
Comparison: Feist-Burkhardt 1995b, p. 213-214
Weiachia fenestrata differs from other species of the genus in having an endocyst with aperidinioid shape, and consistently present fenestrae. It differs from speciesbelongingto Moesiodinium Antones,cu 1974 emend. Below 1987 in having an adnate rather than free operculum. Occurrence. Late Toarcian, Thouarsense Zone, Switzerland.