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Dodekovia syzygia
Dodekovia syzygia Dörhöfer and Davies, 1980, p.26, figs.11,23B,E,H;26A-D,F-G. Emendation: Below, 1987a, p.121-122, as Dodekovia syzygia.
Originally (and now) Dodekovia, subsequently Apteodinium. Prauss (1989, p.19) retained this species in Dodekovia.
Taxonomic junior synonym: Ovalicysta hiata, according to Below (1987a, p.121) - however, Lentin and Williams (1989, p.269) retained Ovalicysta hiata.
Holotype: Dörhöfer and Davies, 1980, figs.26A-D; Fensome et al., 1995, figs.1-4 - p.1827.
Locus typicus: Savik Formation, Reindeer penin, Ellef Ringnes Island, Sverdrup Basin, Arctic Canada
Age: Toarcian-Bathonian.
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Dodekovia syzygia, Dörhöfer and Davies, 1980, emend. Below, 1987a, as emended by Below (1987a), arrangement of the vesicles on the dinoflagellate amphiesma cop, pop, cap, 5', 3a’ 6-7", 7c, 5"’, 2"”, as, y, z, ps, 1"” and 2"” are located symmetrically on either side of the dorsoventral plane, tegulation 5*-4*, 3**, 6***, 2****, 7c, 3x, 4xx, nxxx. Cystic habit proximate, acavate, ovaloidal, tapering to a broad-based apical horn, epicyst and smaller hypocyst separated by weakly laevorotatory shallow cingulum; size small; wall composed of thin pedium and firm, spongy luxuria with an extremely variable surface texture. The luxuria separates distally into fibres, the fibres thicken at the distal tip into granules, with neighbouring granules fusing into spotty surfaces or forming a locally to completely continuous granular, also shagreen, scabrate, glabrous tegullum; luxuriate ornaments are often absent along the fines, so that deep, narrow grooves separate the areae from one another with rigid luxuriate growth, distal granules of luxuria are slightly thicker along the area margin or fused completely into a continuous tegillum, and so the tabulation is reflected by the areation, partially, completely or not at all. Archeopyle anterior intercalary, 2a, operculum monoareate, secate, opercular formula 2as. Size: holotype 30 µm.
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Original description: D÷rh÷fer and Davies, 1980, p. 26
Diagnosis: A species of Dodekovia with spherical to ovoidal cyst body. Phragma two-layered, fibrous between endo- and periphragm. Ornament densely granulate to punctate. Small apical horns often present. Tabulation 4', 5a, 9'', 8c, 9''', 2p, 2'''', 4s; archeopyle 3P3I.
Length 25(27)30 µm; breadth 18(22)26 µm (12 specimens).
Affinities: D÷rh÷fer and Davies, 1980, p. 26
Remarks: Dodekovia gochtii (Dodekova) comb. nov. differs by its reticulate ornament. Meiourogonyaulax? acanthosphaera (Sarjeant) Sarjeant, 1976 resembles D. syzygia, but differs in archeopyle (AI), tabulation, and size.
See also discussion by Below, 1987, under Dodekovia.
Originally (and now) Dodekovia, subsequently Apteodinium. Prauss (1989, p.19) retained this species in Dodekovia.
Taxonomic junior synonym: Ovalicysta hiata, according to Below (1987a, p.121) - however, Lentin and Williams (1989, p.269) retained Ovalicysta hiata.
Holotype: Dörhöfer and Davies, 1980, figs.26A-D; Fensome et al., 1995, figs.1-4 - p.1827.
Locus typicus: Savik Formation, Reindeer penin, Ellef Ringnes Island, Sverdrup Basin, Arctic Canada
Age: Toarcian-Bathonian.
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Dodekovia syzygia, Dörhöfer and Davies, 1980, emend. Below, 1987a, as emended by Below (1987a), arrangement of the vesicles on the dinoflagellate amphiesma cop, pop, cap, 5', 3a’ 6-7", 7c, 5"’, 2"”, as, y, z, ps, 1"” and 2"” are located symmetrically on either side of the dorsoventral plane, tegulation 5*-4*, 3**, 6***, 2****, 7c, 3x, 4xx, nxxx. Cystic habit proximate, acavate, ovaloidal, tapering to a broad-based apical horn, epicyst and smaller hypocyst separated by weakly laevorotatory shallow cingulum; size small; wall composed of thin pedium and firm, spongy luxuria with an extremely variable surface texture. The luxuria separates distally into fibres, the fibres thicken at the distal tip into granules, with neighbouring granules fusing into spotty surfaces or forming a locally to completely continuous granular, also shagreen, scabrate, glabrous tegullum; luxuriate ornaments are often absent along the fines, so that deep, narrow grooves separate the areae from one another with rigid luxuriate growth, distal granules of luxuria are slightly thicker along the area margin or fused completely into a continuous tegillum, and so the tabulation is reflected by the areation, partially, completely or not at all. Archeopyle anterior intercalary, 2a, operculum monoareate, secate, opercular formula 2as. Size: holotype 30 µm.
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Original description: D÷rh÷fer and Davies, 1980, p. 26
Diagnosis: A species of Dodekovia with spherical to ovoidal cyst body. Phragma two-layered, fibrous between endo- and periphragm. Ornament densely granulate to punctate. Small apical horns often present. Tabulation 4', 5a, 9'', 8c, 9''', 2p, 2'''', 4s; archeopyle 3P3I.
Length 25(27)30 µm; breadth 18(22)26 µm (12 specimens).
Affinities: D÷rh÷fer and Davies, 1980, p. 26
Remarks: Dodekovia gochtii (Dodekova) comb. nov. differs by its reticulate ornament. Meiourogonyaulax? acanthosphaera (Sarjeant) Sarjeant, 1976 resembles D. syzygia, but differs in archeopyle (AI), tabulation, and size.
See also discussion by Below, 1987, under Dodekovia.