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Papuadinium
From Williams et al., 2017:
[Papuadinium, Davey, 1988, p. 42
Type Species: originally as Cannosphaeropsis apiculata, Cookson and Eisenack, 1960b (pl.39, fig.15)] ; Papuadinium apiculatum, Davey, 1988
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Original description: [Davey, 1988]:
Diagnosis:
Shape: Cyst skolochorate. Body spherical to subspherical probably with some dorsoventral flattening.
Wall: Apparently two layered with only the periphragm forming the processes. Acavate. Surface smooth to scabrate.
Processes: Solid, sutural and appear to be only gonal in position. Cingular processes only developed on the hypocystal margin of the cingulum. Processes divide distally to give rise to two or three branches which form sutural trabeculae.
Paratabulation: Sutural ridges/crests are absent. The gonal processes, sutural trabeculae and archaeopyle suggest gonyaulacacean affinities.
Archaeopyle: Combination epicystal, Type tAtP. Opeculum typically detached. Outline circular.
Affinities:
The combination of epicystal archaeopyle and trabeculae differentiates the genus Papuadinium from all previously described genera. Rigaudella Below 1982 is superficially similar but possesses an apical archaeopyle and plate-centered, often tubiform, processes. Callaiosphaeridium Davey and Williams 1966 has an epicystal archaeopyle, but has both tabular and solid gonal processes and no trabeculae.
[Papuadinium, Davey, 1988, p. 42
Type Species: originally as Cannosphaeropsis apiculata, Cookson and Eisenack, 1960b (pl.39, fig.15)] ; Papuadinium apiculatum, Davey, 1988
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey, 1988]:
Diagnosis:
Shape: Cyst skolochorate. Body spherical to subspherical probably with some dorsoventral flattening.
Wall: Apparently two layered with only the periphragm forming the processes. Acavate. Surface smooth to scabrate.
Processes: Solid, sutural and appear to be only gonal in position. Cingular processes only developed on the hypocystal margin of the cingulum. Processes divide distally to give rise to two or three branches which form sutural trabeculae.
Paratabulation: Sutural ridges/crests are absent. The gonal processes, sutural trabeculae and archaeopyle suggest gonyaulacacean affinities.
Archaeopyle: Combination epicystal, Type tAtP. Opeculum typically detached. Outline circular.
Affinities:
The combination of epicystal archaeopyle and trabeculae differentiates the genus Papuadinium from all previously described genera. Rigaudella Below 1982 is superficially similar but possesses an apical archaeopyle and plate-centered, often tubiform, processes. Callaiosphaeridium Davey and Williams 1966 has an epicystal archaeopyle, but has both tabular and solid gonal processes and no trabeculae.