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Sirmiodinium grossii
Sirmiodinium grossii Alberti, 1961, p.22, pl.7, figs.5–7; pl.12, fig.5. Emendation: Warren, 1973, p.104–105
Taxonomic junior synonym: Scriniodinium (subsequently Sirmiodinium) pseudocrystallinum, according to Drugg (1978, p.73) and Kunz (1990, p.39).
Holotype: Alberti, 1961, pl.7, fig.6
Locus typicus: Haverlahwiese (Salzgitter), Germany
Stratum typicum: Late Hauterivian-Late Baremian
Translation Alberti, 1961: Stover and Evitt, 1978
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Sirmiodinium grossii Alberti, 1961, emend. Warren, 1973. As emended by Warren (1973), cyst dorso-ventrally flattened, pentagonal to trilobate in dorsal or ventral view. Two walls in contact on dorsal and ventral surfaces, separated at ambitus, amount of separation greatest in hypotract; junction of walls marked by line parallel to and within ambitus of endophragm; periphragm smooth, thinner than endophragm; endophragm scabrate to granular. Striate growth bands rarely reflected on periphragm. Where separated from endophragm, periphragm is perforated by various small openings: always at antapex, by a single polygonal opening or by a group of small, circular to oval openings; commonly in reflected cingulum and on epitract by circular to oval openings which show no consistent pattern of arrangement; rarely on hypotract by similar openings. Rarely, openings in reflecte cingulum coalesce, causing periphragm to be absent from lateral portions of reflected cingulum. Blunt apical horn present. Tabulation distinct to nearly indiscernible, is 4', 6", 6c, 6"’, 1p, 1"”. Cingulum offset. Archeopyle compound, apical plus precingular. Operculum in two pieces, one corresponds to apical plates, attached along anterior edge of reflected plate 6" and reflected sulcus, or rarely, free; the other corresponds to plate 3", attached at reflected cingulum. Size: pericyst length 87-92 µm, width 81-85 µm, in holotype endocyst 72 µm long, 61 µm wide.
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Original description: Alberti 1961, p. 22.
Diagnosis (the same as that of the genus): Shell flattened, in outline approximately pentagonal (almost hexagonal). Inner body oval to rounded hexagonal, particularly fattened at the antapical pole. An outer swelling, which is interrupted in the region of the equator by a transverse furrow, encloses the inner body in a narrow marginal zone (dorsal andventral). By this means a more or less ellipsoidal central part of the ventral and dorsal sides remains free of the surrounding shell. The epitheca and the slightly larger hypotheca form two trapezoids of unequal size joined at their bases; the antapical outer edge is slightly concave. Thus two slightly diverging antapical protrusions at the outer ends are sometimes indicated. Epitheca with a short, projecting apical protrusion.
Additions: Characteristic for the genus and the single species is the envelope of the inner capsule in a narrow marginal zone, which in heigth of the equator is interrupted by a broad transverse furrow, which posseses a turned trapezoidal crosssection. The mebrane of the envelope is crystal- clear, almost colourless; the one of the inner capsule is transparent and of a pale yellow colour. The archaeopyle is not yet demonstrated.
Dimensions: Holotype: length 91 Ám, breadth 86 Ám, legth inner body 72 Ám, breadth inner body 61 Ám. Size range: length: 87-92 Ám, breadth: 81-85 Ám.
Emended description: Warren, 1973, p. 104-105
Cyst dorso-ventrally flattened, pentagonal to trilobate in dorsal or ventral view. Two walls, in contact on dorsal and ventral surfaces, separated at ambitus, amount of separation greatest in hypotract; junction of walls marked by line parallel to and within ambitus of endophragm; periphragm smooth, thinner than endophragm; endophragm scabrate to granular. Striate growth bands rarely reflected on periphragm. Where separated from endophragm, periphragm is perforated by various small openings: always at the antapex, by a single polygonal opening or by a group of small, circular to oval openings; commonly in reflected cingulum and on epitract by circular to oval openings which show no consistent pattern of arrangment; rarely on hypotract by similar openings. Rarely, openings in reflected cingulum coalesce, causing periphragm to be absent from lateral portions of reflected cingulum. Blunt apical horn present on periphragm, present or absent on endophragm. Tabulation distinct to nearly indiscernible, reflected by low sutural ridges formed by folds of periphragm. Plate formula 4', 6'', 6c, 6''', 1p, 1''''. Reflected apical plate nearly equal; plates 1' and 4' ventral; plate 2' and 3' dorsal. Reflected plates 1'' through 5'' nearly equal, reflected plate 6'' narrow; plates 1'', 5'', and 6'' ventral; reflected plates 2'', 3'', and 4'' dorsal. Reflected plate 1''' small, nearly incorporated into sulcus; reflected plates 2''' through 6''', 1p, and 1'''' variable in size and shape, depending on amount of extension of posterolateral lobes; reflected plates 2''' and 1p similar in size and shape on individual specimens. Reflected cingulum low spiral, offset at reflected sulcus by one cingulum width; reflected on lateral periphragm surface by various structures: sutural ridges only, groove, or zone of perforations which rarely coalesce. Reflected sulcus straight, undivided or divided into a maximum of five reflected plates plus pore scars. Archaeopyle compound, apical plus precingular. Operculum in two pieces; one corresponds to apical plates, attached along anterior edge of reflected plate 6'' and reflected sulcus, or rarely, free; the other corresponds to plate 3'', attached at reflected cingulum.
Taxonomic junior synonym: Scriniodinium (subsequently Sirmiodinium) pseudocrystallinum, according to Drugg (1978, p.73) and Kunz (1990, p.39).
Holotype: Alberti, 1961, pl.7, fig.6
Locus typicus: Haverlahwiese (Salzgitter), Germany
Stratum typicum: Late Hauterivian-Late Baremian
Translation Alberti, 1961: Stover and Evitt, 1978
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Sirmiodinium grossii Alberti, 1961, emend. Warren, 1973. As emended by Warren (1973), cyst dorso-ventrally flattened, pentagonal to trilobate in dorsal or ventral view. Two walls in contact on dorsal and ventral surfaces, separated at ambitus, amount of separation greatest in hypotract; junction of walls marked by line parallel to and within ambitus of endophragm; periphragm smooth, thinner than endophragm; endophragm scabrate to granular. Striate growth bands rarely reflected on periphragm. Where separated from endophragm, periphragm is perforated by various small openings: always at antapex, by a single polygonal opening or by a group of small, circular to oval openings; commonly in reflected cingulum and on epitract by circular to oval openings which show no consistent pattern of arrangement; rarely on hypotract by similar openings. Rarely, openings in reflecte cingulum coalesce, causing periphragm to be absent from lateral portions of reflected cingulum. Blunt apical horn present. Tabulation distinct to nearly indiscernible, is 4', 6", 6c, 6"’, 1p, 1"”. Cingulum offset. Archeopyle compound, apical plus precingular. Operculum in two pieces, one corresponds to apical plates, attached along anterior edge of reflected plate 6" and reflected sulcus, or rarely, free; the other corresponds to plate 3", attached at reflected cingulum. Size: pericyst length 87-92 µm, width 81-85 µm, in holotype endocyst 72 µm long, 61 µm wide.
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Original description: Alberti 1961, p. 22.
Diagnosis (the same as that of the genus): Shell flattened, in outline approximately pentagonal (almost hexagonal). Inner body oval to rounded hexagonal, particularly fattened at the antapical pole. An outer swelling, which is interrupted in the region of the equator by a transverse furrow, encloses the inner body in a narrow marginal zone (dorsal andventral). By this means a more or less ellipsoidal central part of the ventral and dorsal sides remains free of the surrounding shell. The epitheca and the slightly larger hypotheca form two trapezoids of unequal size joined at their bases; the antapical outer edge is slightly concave. Thus two slightly diverging antapical protrusions at the outer ends are sometimes indicated. Epitheca with a short, projecting apical protrusion.
Additions: Characteristic for the genus and the single species is the envelope of the inner capsule in a narrow marginal zone, which in heigth of the equator is interrupted by a broad transverse furrow, which posseses a turned trapezoidal crosssection. The mebrane of the envelope is crystal- clear, almost colourless; the one of the inner capsule is transparent and of a pale yellow colour. The archaeopyle is not yet demonstrated.
Dimensions: Holotype: length 91 Ám, breadth 86 Ám, legth inner body 72 Ám, breadth inner body 61 Ám. Size range: length: 87-92 Ám, breadth: 81-85 Ám.
Emended description: Warren, 1973, p. 104-105
Cyst dorso-ventrally flattened, pentagonal to trilobate in dorsal or ventral view. Two walls, in contact on dorsal and ventral surfaces, separated at ambitus, amount of separation greatest in hypotract; junction of walls marked by line parallel to and within ambitus of endophragm; periphragm smooth, thinner than endophragm; endophragm scabrate to granular. Striate growth bands rarely reflected on periphragm. Where separated from endophragm, periphragm is perforated by various small openings: always at the antapex, by a single polygonal opening or by a group of small, circular to oval openings; commonly in reflected cingulum and on epitract by circular to oval openings which show no consistent pattern of arrangment; rarely on hypotract by similar openings. Rarely, openings in reflected cingulum coalesce, causing periphragm to be absent from lateral portions of reflected cingulum. Blunt apical horn present on periphragm, present or absent on endophragm. Tabulation distinct to nearly indiscernible, reflected by low sutural ridges formed by folds of periphragm. Plate formula 4', 6'', 6c, 6''', 1p, 1''''. Reflected apical plate nearly equal; plates 1' and 4' ventral; plate 2' and 3' dorsal. Reflected plates 1'' through 5'' nearly equal, reflected plate 6'' narrow; plates 1'', 5'', and 6'' ventral; reflected plates 2'', 3'', and 4'' dorsal. Reflected plate 1''' small, nearly incorporated into sulcus; reflected plates 2''' through 6''', 1p, and 1'''' variable in size and shape, depending on amount of extension of posterolateral lobes; reflected plates 2''' and 1p similar in size and shape on individual specimens. Reflected cingulum low spiral, offset at reflected sulcus by one cingulum width; reflected on lateral periphragm surface by various structures: sutural ridges only, groove, or zone of perforations which rarely coalesce. Reflected sulcus straight, undivided or divided into a maximum of five reflected plates plus pore scars. Archaeopyle compound, apical plus precingular. Operculum in two pieces; one corresponds to apical plates, attached along anterior edge of reflected plate 6'' and reflected sulcus, or rarely, free; the other corresponds to plate 3'', attached at reflected cingulum.