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Polystephanephorus caulleryi
Polystephanophorus caulleryi (Deflandre, 1938) Courtinat 1989
Now Adnatosphaeridium. Originally Hystrichosphaeridium, subsequently Cannosphaeropsis, thirdly (and now) Adnatosphaeridium, fourthly Polystephanephorus. Stancliffe and Sarjeant, 1990 emended the diagnosis of this species and retained it in Adnatosphaeridium Williams and Downie, 1966.
Holotype: Deflandre, 1938, pl.11, fig.2; Stancliffe and Sarjeant, 1990, pl.1, figs.3-4
Age: Oxfordian
Translation Courtinat, 1989: LPP
Courtinat, 1989, p.171
Remark: This new combination is proposed because P. caulleryi possesses ring-trabeculae and trabeculae between the process complexes. The type species of Adnatosphaeridium, A. vittatum, does not present ring-trabeculae, which constitutes differential generic characteristic.
Emended diagnosis: Stancliffe and Sarjeant, 1990, p.200
Skolochorale dinoflagellate cysts, with central body spherical to subspherical and of intermediate to large overall size. Phragma smooth to finely granulate. Central body surmounted by numerous solid, slender processes which are consistently bifurcate or multifurcate and may be distally expanded. Processes may be deeply or medially furcate and occasionally branch proximally. Processes variably interconnected distally by solid, slender, smooth to irregularly denticulate trabeculae. Paratabulation gonyaulacacean, indicated by intratabular processes (or clusters of processes). Process clusters irregular, occasionally exhibiting annulate or arcuate organisation: this is shown best in the precingular, postcingular and antapical areas. Apical, cingular, sulcal and posterior intercalary paraplates give rise to single processes or to small, closely spaced process clusters. Trabeculae may or may not interconnect process clusters. Paratabulation formula probably 4', 6". 6c, 6''', 1p, 1'''', x- ?s. Archeopyle apical, type (tA), operculum free.
Description: Stancliffe and Sarjeant, 1990, p. 200
This species of Adnatosphaeridium has a spherical to subspherical, smooth to finely granulate cyst body bearing numerous thin, solid processes, interpreted as extensions of the periphragm. The process length is variable within a population (20-31% of the overall cyst diameter), but relatively consistent on any individual specimen. The processes, though consistently arcate, are otherwise variable in distal morphology: they may be expanded and interconnected by irregularly denticulate trabeculae. Medial branching of the processes may occur and rarely they bifumate proximally. The lager paraplate areas (precingular, postcingular and antapical) are characterised by distinct intratabular process clusters which are typically irregular, rarely annulate or arcuate, in organisation. Individual processes within these relatively large clusters are normally trabeculate. The size, complexity and trabecular connection between adjacent clusters render some precingular and postcingular clusters difficult to distinguish. The smaller apical, paracingular, parasulcal and posterior intercalary paraplates have solitary, generally bifurcate, processes or small, closely paced process clusters. The large number and complexity of he processes renders the paratabulation formula difficult to determine precisely; however, it appears to be standard gonyaulacacean. The archaeopyle is apical, type (tA), with a free operculum.
Now Adnatosphaeridium. Originally Hystrichosphaeridium, subsequently Cannosphaeropsis, thirdly (and now) Adnatosphaeridium, fourthly Polystephanephorus. Stancliffe and Sarjeant, 1990 emended the diagnosis of this species and retained it in Adnatosphaeridium Williams and Downie, 1966.
Holotype: Deflandre, 1938, pl.11, fig.2; Stancliffe and Sarjeant, 1990, pl.1, figs.3-4
Age: Oxfordian
Translation Courtinat, 1989: LPP
Courtinat, 1989, p.171
Remark: This new combination is proposed because P. caulleryi possesses ring-trabeculae and trabeculae between the process complexes. The type species of Adnatosphaeridium, A. vittatum, does not present ring-trabeculae, which constitutes differential generic characteristic.
Emended diagnosis: Stancliffe and Sarjeant, 1990, p.200
Skolochorale dinoflagellate cysts, with central body spherical to subspherical and of intermediate to large overall size. Phragma smooth to finely granulate. Central body surmounted by numerous solid, slender processes which are consistently bifurcate or multifurcate and may be distally expanded. Processes may be deeply or medially furcate and occasionally branch proximally. Processes variably interconnected distally by solid, slender, smooth to irregularly denticulate trabeculae. Paratabulation gonyaulacacean, indicated by intratabular processes (or clusters of processes). Process clusters irregular, occasionally exhibiting annulate or arcuate organisation: this is shown best in the precingular, postcingular and antapical areas. Apical, cingular, sulcal and posterior intercalary paraplates give rise to single processes or to small, closely spaced process clusters. Trabeculae may or may not interconnect process clusters. Paratabulation formula probably 4', 6". 6c, 6''', 1p, 1'''', x- ?s. Archeopyle apical, type (tA), operculum free.
Description: Stancliffe and Sarjeant, 1990, p. 200
This species of Adnatosphaeridium has a spherical to subspherical, smooth to finely granulate cyst body bearing numerous thin, solid processes, interpreted as extensions of the periphragm. The process length is variable within a population (20-31% of the overall cyst diameter), but relatively consistent on any individual specimen. The processes, though consistently arcate, are otherwise variable in distal morphology: they may be expanded and interconnected by irregularly denticulate trabeculae. Medial branching of the processes may occur and rarely they bifumate proximally. The lager paraplate areas (precingular, postcingular and antapical) are characterised by distinct intratabular process clusters which are typically irregular, rarely annulate or arcuate, in organisation. Individual processes within these relatively large clusters are normally trabeculate. The size, complexity and trabecular connection between adjacent clusters render some precingular and postcingular clusters difficult to distinguish. The smaller apical, paracingular, parasulcal and posterior intercalary paraplates have solitary, generally bifurcate, processes or small, closely paced process clusters. The large number and complexity of he processes renders the paratabulation formula difficult to determine precisely; however, it appears to be standard gonyaulacacean. The archaeopyle is apical, type (tA), with a free operculum.