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Sverdrupiella mutabilis
Sverdrupiella mutabilis Bujak and Fisher, 1976
Holotype: Bujak and Fisher, 1976, pl.4, fig.1; pl.5, fig.8; text-fig.2J
Locus typicus: Skybattle Bay C-15, cuttings 78107900'; Queen Elizabeth Islands, arctic Canada
Stratum typicum: ?Carnian-Norian
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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.
Sverdrupiella mutabilis Bujak and Fisher, 1976. Diagnosis from Bujak and Fisher (1976, p.50), Cavate to bicavate cysts, capsule spherical, oval or weakly rhomboidal in lateral view, often thin-walled, indistinct and sometimes absent. Periphragm longer than broad, forming conical epitract commonly bearing tapering apical horn. Hypotract variable, always delimiting an antapical pericoel. Variants including hypotract of trapezoidal outline which is truncated, an acutely conical to subconical, hypotract terminally rounded, a hypotract adpressed to capsule except where it forms broadly or narrowly quadrangular pericoel, and asymmetrical hypotract with deeply incised sulcus. First three variants commonly seen in dorsoventral view and latter variant typically with more lateral compression. Intergradation common between all variants. Cingulum circular or laevorotatory. Cingulum and sulcus defined by smooth or undulate crests sometimes bearing few verrucae and sometimes acuminate spines, particularly on variant with conical hypotract. Remainder of periphragm surface usually smooth, but occasional verrucae and short acuminate spines may rarely be present. Archeopyle formed in periphragm by loss or displacement of usually two, but sometimes possibly three, anterior intercalary plates which, when attached are joined along their lateroposterior or lateral margins. Mode of archeopyle formation in capsule problematic. Size: pericyst length 68-117 µm, width 46-72 µm, endocyst length 38-62 µm, width 40-63 µm.
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Original diagnosis: Bujak and Fisher, 1976, p.50
Cavate to bicavate cysts, capsule spherical, oval or weakly rhomboidal in lateral view, often thin-walled, indistinct, and sometimes absent. Periphragm longer than broad, forming conical epitract commonly bearing tapering apical horn. Hypotract variable, always delimiting an antapical pericoel. Variants including hypotract of trapezoidal outline which is truncated, an acutely conical to subconical hypotract terminally rounded, a hypotract adpressed to capsule except where it forms broadly or narrowly quadrangular pericoel, and asymmetrical hypotract with deeply incised sulcus. First three variants commonly seen in dorsoventral view and latter variant typically with more lateral compression. Intergradation common between all variants. Cingulum circular or laevo-rotary. Cingulum and sulcus defined by smooth or undulate crests sometimes bearing few verrucae and sometimes acuminate spines, particularly on variant with conical hypotract. Remainder of periphragm surface usually smooth, but occasional verrucae and short acuminate spines may rarely be present. Archeopyle formed in periphragm by loss or displacement of usually two, but sometimes possibly three anterior intercalary plates which, when attached, are joined along their lateroposterior or lateral margins. Mode of archeopyle formation in capsule problematic.
DImensions: Holotype, periphragm length 88 µm, periphragm breadth 48 µm, capsule length 52 µm, capsule breadth 45 µm. Observed range, periphragm length 68-117 µm, periphragm breadth 46-72 µm, capsule length 38-62 µm, capsule breadth 40-63 µm.
Holotype: Bujak and Fisher, 1976, pl.4, fig.1; pl.5, fig.8; text-fig.2J
Locus typicus: Skybattle Bay C-15, cuttings 78107900'; Queen Elizabeth Islands, arctic Canada
Stratum typicum: ?Carnian-Norian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Sverdrupiella mutabilis Bujak and Fisher, 1976. Diagnosis from Bujak and Fisher (1976, p.50), Cavate to bicavate cysts, capsule spherical, oval or weakly rhomboidal in lateral view, often thin-walled, indistinct and sometimes absent. Periphragm longer than broad, forming conical epitract commonly bearing tapering apical horn. Hypotract variable, always delimiting an antapical pericoel. Variants including hypotract of trapezoidal outline which is truncated, an acutely conical to subconical, hypotract terminally rounded, a hypotract adpressed to capsule except where it forms broadly or narrowly quadrangular pericoel, and asymmetrical hypotract with deeply incised sulcus. First three variants commonly seen in dorsoventral view and latter variant typically with more lateral compression. Intergradation common between all variants. Cingulum circular or laevorotatory. Cingulum and sulcus defined by smooth or undulate crests sometimes bearing few verrucae and sometimes acuminate spines, particularly on variant with conical hypotract. Remainder of periphragm surface usually smooth, but occasional verrucae and short acuminate spines may rarely be present. Archeopyle formed in periphragm by loss or displacement of usually two, but sometimes possibly three, anterior intercalary plates which, when attached are joined along their lateroposterior or lateral margins. Mode of archeopyle formation in capsule problematic. Size: pericyst length 68-117 µm, width 46-72 µm, endocyst length 38-62 µm, width 40-63 µm.
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Original diagnosis: Bujak and Fisher, 1976, p.50
Cavate to bicavate cysts, capsule spherical, oval or weakly rhomboidal in lateral view, often thin-walled, indistinct, and sometimes absent. Periphragm longer than broad, forming conical epitract commonly bearing tapering apical horn. Hypotract variable, always delimiting an antapical pericoel. Variants including hypotract of trapezoidal outline which is truncated, an acutely conical to subconical hypotract terminally rounded, a hypotract adpressed to capsule except where it forms broadly or narrowly quadrangular pericoel, and asymmetrical hypotract with deeply incised sulcus. First three variants commonly seen in dorsoventral view and latter variant typically with more lateral compression. Intergradation common between all variants. Cingulum circular or laevo-rotary. Cingulum and sulcus defined by smooth or undulate crests sometimes bearing few verrucae and sometimes acuminate spines, particularly on variant with conical hypotract. Remainder of periphragm surface usually smooth, but occasional verrucae and short acuminate spines may rarely be present. Archeopyle formed in periphragm by loss or displacement of usually two, but sometimes possibly three anterior intercalary plates which, when attached, are joined along their lateroposterior or lateral margins. Mode of archeopyle formation in capsule problematic.
DImensions: Holotype, periphragm length 88 µm, periphragm breadth 48 µm, capsule length 52 µm, capsule breadth 45 µm. Observed range, periphragm length 68-117 µm, periphragm breadth 46-72 µm, capsule length 38-62 µm, capsule breadth 40-63 µm.