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Trichodinium australe
From Fensome et al., 2019:
Trichodinium australe (Burger, 1980b, p.268–269, figs.5C–D,6A) Fauconnier in Fauconnier and Masure, 2004, p.116.
Emendation: Fauconnier in Fauconnier and Masure, 2004, p.116, as Trichodinium australe.
Holotype: Burger, 1980b, fig.5D; Fauconnier and Masure, 2004, pl.15, figs.3–5.
Originally Cleistosphaeridium, subsequently Circulodinium, thirdly (and now) Trichodinium.
Age: Neocomian.
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Original description:
1980 Cleistosphaeridium sp. A (pars) Burger, p. 78, pl.31, fig. 6; pl. 32, fig. 1 (not Burger, pl. 32, fig. 6)
Derivation of name. Referring to the known regional distribution of the species.
Holotype. BMR Orford Bay 1, depth 76.9 m, upper Helby Beds; Zone DK1, near Jurassic-Cretaceous boundary, late Tithonian or perhaps earliest Berriasian (MFP6281-1, 430/1040, CPC 19681; Fig. 5D).
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.
Distribution. An uncommon species in the Helby Beds (MFP4032, 6269, 6281), Gilbert River Formation (MFP4031, 6362, 7042), and basal Rolling Downs Group (MFP4034, 6304). Also infrequently present in the Aptian and early Albian of southeastern Queensland.
Comparison. 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.
Trichodinium australe (Burger, 1980b, p.268–269, figs.5C–D,6A) Fauconnier in Fauconnier and Masure, 2004, p.116.
Emendation: Fauconnier in Fauconnier and Masure, 2004, p.116, as Trichodinium australe.
Holotype: Burger, 1980b, fig.5D; Fauconnier and Masure, 2004, pl.15, figs.3–5.
Originally Cleistosphaeridium, subsequently Circulodinium, thirdly (and now) Trichodinium.
Age: Neocomian.
---------------------------------------------------------------------------------------------------
Original description:
1980 Cleistosphaeridium sp. A (pars) Burger, p. 78, pl.31, fig. 6; pl. 32, fig. 1 (not Burger, pl. 32, fig. 6)
Derivation of name. Referring to the known regional distribution of the species.
Holotype. BMR Orford Bay 1, depth 76.9 m, upper Helby Beds; Zone DK1, near Jurassic-Cretaceous boundary, late Tithonian or perhaps earliest Berriasian (MFP6281-1, 430/1040, CPC 19681; Fig. 5D).
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.
Distribution. An uncommon species in the Helby Beds (MFP4032, 6269, 6281), Gilbert River Formation (MFP4031, 6362, 7042), and basal Rolling Downs Group (MFP4034, 6304). Also infrequently present in the Aptian and early Albian of southeastern Queensland.
Comparison. 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.