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Sahulidinium
From Williams et al., 2017:
[Sahulidinium, Stover and Helby, 1987a, p. 113
Type species: Sahulidinium ottii, Stover and Helby, 1987a (figs.13I–J)]
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Original description: [Stover and Helby, 1987]:
Synopsis:
Cysts proximate, elongate-ellipsoidal to arcuate-reniform in outline; autophragm bearing nontabular and generally some parasutural features of low to moderate relief; archeopyle apical, type (tA), operculum generally attached; paratabulation of epicyst 6` - ?7`, 6a, 7", Xc, indications of paratabulation on hypocyst vague or absent.
Description:
Shape. Elongate ellipsoidal in dorsoventral view, arcuate-reniform in lateral view.
Wall relationships: Autophragm only.
Wall features: Ornamentation of coni, spinules, granules or other features of low to moderate relief, some nontabular, others parasutural.
Archeopyle: Apical, type (tA), principal suture zigzag, accessory sutures may be present; operculum generally attached.
Paratabulation: Indicated by archeopyle and by parasutural features; formula for epicyst: 6` - ?7`, 6a, 7", Xc; paratabulation for hypocyst undetermined.
Paracingulum: Not indicated, or shown by low, parallel, transverse ridges, undivided, ends offset markedly.
Parasulcus: Not expressed, or outlined by vague parasutural features on hypocyst.
Size: Intermediate to large.
Affinities:
Sahulidinium has a rhaetogonyaulacacean paratabulation pattern. However, it is distinguished from Rhaetogonyalax Sarjeant in Davey et al. emend. Fisher and van Helden, 1979, by having 6 intercalary paraplates, 6 anteriorly gabled precingular paraplates (2`` to 7``) and a small, quadrate 1`` paraplate. Sahulidinium also lacks the broad, indented paracingulum and the apical and antapical horns of Rhaetogonyaulax. shublikodinium Wiggins, 1973 is smaller, and has a paratabulation pattern apparently identical to that of Rhaetogonyaulax.
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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.
Sahulidinium Stover and Helby, 1987a. According to Stover and Helby (1987a, p.113), the cysts are proximate, elongate-ellipsoidal to arcuate-reniform in outline; autophragm bearing nontabular and generally some parasutural features of low to moderate relief; archeopyle apical,. Type (tA), operculum generally attached, paratabulation of epicyst 6`-?7`, 6a, 7", xc, indications of paratabulation on hypocyst vague or absent.
[Sahulidinium, Stover and Helby, 1987a, p. 113
Type species: Sahulidinium ottii, Stover and Helby, 1987a (figs.13I–J)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Stover and Helby, 1987]:
Synopsis:
Cysts proximate, elongate-ellipsoidal to arcuate-reniform in outline; autophragm bearing nontabular and generally some parasutural features of low to moderate relief; archeopyle apical, type (tA), operculum generally attached; paratabulation of epicyst 6` - ?7`, 6a, 7", Xc, indications of paratabulation on hypocyst vague or absent.
Description:
Shape. Elongate ellipsoidal in dorsoventral view, arcuate-reniform in lateral view.
Wall relationships: Autophragm only.
Wall features: Ornamentation of coni, spinules, granules or other features of low to moderate relief, some nontabular, others parasutural.
Archeopyle: Apical, type (tA), principal suture zigzag, accessory sutures may be present; operculum generally attached.
Paratabulation: Indicated by archeopyle and by parasutural features; formula for epicyst: 6` - ?7`, 6a, 7", Xc; paratabulation for hypocyst undetermined.
Paracingulum: Not indicated, or shown by low, parallel, transverse ridges, undivided, ends offset markedly.
Parasulcus: Not expressed, or outlined by vague parasutural features on hypocyst.
Size: Intermediate to large.
Affinities:
Sahulidinium has a rhaetogonyaulacacean paratabulation pattern. However, it is distinguished from Rhaetogonyalax Sarjeant in Davey et al. emend. Fisher and van Helden, 1979, by having 6 intercalary paraplates, 6 anteriorly gabled precingular paraplates (2`` to 7``) and a small, quadrate 1`` paraplate. Sahulidinium also lacks the broad, indented paracingulum and the apical and antapical horns of Rhaetogonyaulax. shublikodinium Wiggins, 1973 is smaller, and has a paratabulation pattern apparently identical to that of Rhaetogonyaulax.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Sahulidinium Stover and Helby, 1987a. According to Stover and Helby (1987a, p.113), the cysts are proximate, elongate-ellipsoidal to arcuate-reniform in outline; autophragm bearing nontabular and generally some parasutural features of low to moderate relief; archeopyle apical,. Type (tA), operculum generally attached, paratabulation of epicyst 6`-?7`, 6a, 7", xc, indications of paratabulation on hypocyst vague or absent.