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Cleistosphaeridium australe
Cleistosphaeridium australe, (Burger, 1980b, p.268-269, figs.5C-D,6A), Islam, 1993, p.83; Emendation: Fauconnier in Fauconnier and Masure, 2004, p.116, as Trichodinium australe.
NOW Trichodinium. Originally Cleistosphaeridium, subsequently Circulodinium, thirdly (and now) Trichodinium.
Holotype: Burger, 1980b, fig.5D; Fauconnier and Masure, 2004, pl.15, figs.3-5.
Type locality: upper Helby Beds; Zone DK1, near Jurassic-Cretaceous boundary, late Tithonian or perhaps earliest Berriasian (MFP6281-1, 430/1040, CPC 19681; Fig. 5D).
Distribution: uncommon in the Helby Beds (MFP4032, 6269, 6281), Gilbert River Formation (MFP4031, 6362, 7042), and basal Rolling Downs Group (MFP4034, 6304); infrequently present in the Aptian and early Albian of southeastern Queensland.
Age: Neocomian.
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Original description as Cleistosphaeridium sp. A (pars): [Burger, p. 78, pl.31, fig. 6; pl. 32, fig. 1 (not Burger, pl. 32, fig. 6)]:
Description:
Cyst spherical, dehisced cyst broadly cupshaped.
Autophragm very thin, psilate, usually broadly folded, supporting over 300 uniform and most likely nontabular processes.
Processes solid, flexuous or sometimes stiff, 4-8 µm high, 1-1.5 µm basal diameter, tapering, with pointed or minutely capitate to bifid tips. Archaeopyle apical, margin zigzag with tiny notches at paraplate junctions. Operculum rarely preserved.
No parasulcus, paracingulum, or distinct parasutures apparent. Equatorial diameter of cyst cavity (8 specimens) 34-46 µm.
Affinities:
These specimens differ from most other species of the genus by the possession of numerous short, uniform, tapering processes. Cleistosphaeridium ancoriferum (Cookson & Eisenack) Davey et al. 1966, and C. huguoniotii (Valensi)Davey 1969, have hollow and more or less tubiform processes with bifurcate tips.
NOW Trichodinium. Originally Cleistosphaeridium, subsequently Circulodinium, thirdly (and now) Trichodinium.
Holotype: Burger, 1980b, fig.5D; Fauconnier and Masure, 2004, pl.15, figs.3-5.
Type locality: upper Helby Beds; Zone DK1, near Jurassic-Cretaceous boundary, late Tithonian or perhaps earliest Berriasian (MFP6281-1, 430/1040, CPC 19681; Fig. 5D).
Distribution: uncommon in the Helby Beds (MFP4032, 6269, 6281), Gilbert River Formation (MFP4031, 6362, 7042), and basal Rolling Downs Group (MFP4034, 6304); infrequently present in the Aptian and early Albian of southeastern Queensland.
Age: Neocomian.
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Original description as Cleistosphaeridium sp. A (pars): [Burger, p. 78, pl.31, fig. 6; pl. 32, fig. 1 (not Burger, pl. 32, fig. 6)]:
Description:
Cyst spherical, dehisced cyst broadly cupshaped.
Autophragm very thin, psilate, usually broadly folded, supporting over 300 uniform and most likely nontabular processes.
Processes solid, flexuous or sometimes stiff, 4-8 µm high, 1-1.5 µm basal diameter, tapering, with pointed or minutely capitate to bifid tips. Archaeopyle apical, margin zigzag with tiny notches at paraplate junctions. Operculum rarely preserved.
No parasulcus, paracingulum, or distinct parasutures apparent. Equatorial diameter of cyst cavity (8 specimens) 34-46 µm.
Affinities:
These specimens differ from most other species of the genus by the possession of numerous short, uniform, tapering processes. Cleistosphaeridium ancoriferum (Cookson & Eisenack) Davey et al. 1966, and C. huguoniotii (Valensi)Davey 1969, have hollow and more or less tubiform processes with bifurcate tips.