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Distatodinium
From Fensome et al., 2019:
[Distatodinium, Eaton, 1976, p.262–263.
Emendations: Zevenboom and Santarelli in Zevenboom, 1995, p.157–158; Fensome et al., 2009, p.30.
Taxonomic junior synonym: Bipolaribucina, according to Chen et al. (1988, p.6–7). Type: Eaton, 1976, pl.9, fig.1, as Distatodinium craterum.
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Original description: [Eaton, 1976]:
Diagnosis:
Dinoflagellate cysts in which the cyst body has an oval or elongate oval outline.
Processes simple or branched, variable in breadth, flattened and blade-like in cross-section, proximally expanded and ramified. Ramifications typically, but not invariably, complex. Occasionally, slender tubular processes are present. The number of processes varies from about 14 (in some species without an operculum) to about 60 or more. Processes aligned into rows parallel to the long axis of the cyst body, and apparently situated on or close to reflected plate boundaries; many are also arranged in a more or less circular manner around the cyst body.
Archeopyle apical.
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Modified description:
Stover and Evitt 1978, p. 39:
Synopsis:
Cysts skolochorate; body elongate ellipsoidal, with a few to many processes; processes typically expanded distally and with multiple bifurcations; adjacent processes may be connected by trabeculae; paratabulation generally not clearly indicated; archeopyle apical, Type tA.
Description:
Shape: Body elongate ellipsoidal.
Wall relationships: Autophragm only, or endophragm and periphragm.
Wall features: No clearly evident parasutural features. Processes tubular to bladelike; may be connected proximally by ridges or septa, typically expanded distally. Most processes branched, with each branch further subdivided by multiple bifurcations. Some processes may be connected distally by trabeculae. Autophragm or periphragm smooth to faintly ornamented.
Paratabulation: Generally not clearly evident; forms with relatively few processes (14 to 25) seem to indicate that the processes are intratabular, whereas those with many processes (30 or more) suggest that they may be gonal - or at least parasutural - or perhaps a combination of gonal and intratabular.
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag but commonly difficult to discern; operculum free.
Paracingulum: Not indicated, or expressed as an equatorial, process free area.
Parasulcus: Not indicated.
Size: Intermediate to large.
Affinities:
Distatodinium differs from Tanyosphaeridium in having processes that are distally branched and that may be connected distally by trabeculae and proximally by ridges or septa. In Tanyosphaeridium the processes are generally simple and not connected.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Distatodinium Eaton, 1976. Synopsis from Stover and Evitt (1978, p.39). Cysts skolochorate; body elongate ellipsoidal, with few to many processes; processes typically expanded distally and with multiple bifurcations; adjacent processes may be connected by trabeculae; paratabulation generally not clearly indicated; archeopyle apical, type (tA). Distatodinium is quinqueform.
[Distatodinium, Eaton, 1976, p.262–263.
Emendations: Zevenboom and Santarelli in Zevenboom, 1995, p.157–158; Fensome et al., 2009, p.30.
Taxonomic junior synonym: Bipolaribucina, according to Chen et al. (1988, p.6–7). Type: Eaton, 1976, pl.9, fig.1, as Distatodinium craterum.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eaton, 1976]:
Diagnosis:
Dinoflagellate cysts in which the cyst body has an oval or elongate oval outline.
Processes simple or branched, variable in breadth, flattened and blade-like in cross-section, proximally expanded and ramified. Ramifications typically, but not invariably, complex. Occasionally, slender tubular processes are present. The number of processes varies from about 14 (in some species without an operculum) to about 60 or more. Processes aligned into rows parallel to the long axis of the cyst body, and apparently situated on or close to reflected plate boundaries; many are also arranged in a more or less circular manner around the cyst body.
Archeopyle apical.
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Modified description:
Stover and Evitt 1978, p. 39:
Synopsis:
Cysts skolochorate; body elongate ellipsoidal, with a few to many processes; processes typically expanded distally and with multiple bifurcations; adjacent processes may be connected by trabeculae; paratabulation generally not clearly indicated; archeopyle apical, Type tA.
Description:
Shape: Body elongate ellipsoidal.
Wall relationships: Autophragm only, or endophragm and periphragm.
Wall features: No clearly evident parasutural features. Processes tubular to bladelike; may be connected proximally by ridges or septa, typically expanded distally. Most processes branched, with each branch further subdivided by multiple bifurcations. Some processes may be connected distally by trabeculae. Autophragm or periphragm smooth to faintly ornamented.
Paratabulation: Generally not clearly evident; forms with relatively few processes (14 to 25) seem to indicate that the processes are intratabular, whereas those with many processes (30 or more) suggest that they may be gonal - or at least parasutural - or perhaps a combination of gonal and intratabular.
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag but commonly difficult to discern; operculum free.
Paracingulum: Not indicated, or expressed as an equatorial, process free area.
Parasulcus: Not indicated.
Size: Intermediate to large.
Affinities:
Distatodinium differs from Tanyosphaeridium in having processes that are distally branched and that may be connected distally by trabeculae and proximally by ridges or septa. In Tanyosphaeridium the processes are generally simple and not connected.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Distatodinium Eaton, 1976. Synopsis from Stover and Evitt (1978, p.39). Cysts skolochorate; body elongate ellipsoidal, with few to many processes; processes typically expanded distally and with multiple bifurcations; adjacent processes may be connected by trabeculae; paratabulation generally not clearly indicated; archeopyle apical, type (tA). Distatodinium is quinqueform.