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Adnatosphaeridium apenninicum
From Williams, Lentin and Fensome 1998 - Lentin and Williams Index of Fossil Dinoflagellates:
[Adnatosphaeridium apenninicum, Corradini, 1973, p. 163-164, pl.25, figs.4a-b; pl.36, figs.1a-b.
NOW Rigaudella. Originally Adnatosphaeridium, subsequently (and now) Rigaudella.
Holotype: Corradini, 1973, pl.25, figs.4a-b. ]
Locus typicus: Val Baganza, Parma, Italy
Stratum typicum: Campanian-Paleocene
Age: Campanian-?Paleocene
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Original description: [Corradini, 1973, p. 164]:
Diagnosis:
Spherical to ovoidal central body with granular endophragm and smooth to fibrous periphragm. Processes solid, widening distally and interconnected by trabeculae. Apical archeopyle with zig-zag margin.
Description:
Solid or partially hollow intratabular processes arise from the periphragm, one or more in number on a single plate. From the wide base, often with a rootlike appearance, the processes expand distally in a broad, more or less fenestrate platform. Adjacent platforms are interconnected with thin and solid trabeculae having a variable cross-section. Few simple processes are thin, solid, usually paired, and fused proximally along 1/3 to 1/2 of their length. Distally they may have the platforms fused or may be irregularly branched. The branches being connected with distal margins of adjacent processes.
The processes reflect the tabulation 4', 6", 5-(6'''), 0-1p, 1''''.
Apical archeopyle with zig-zag margins, almost always present.
Dimensions:
Holotype: diameter of the central body 40 µm, length of the processes 20-28 µm.
Range: diameter of the central body 38(49)60 µm, length of the processes 20(23)30 µm.
Affinities:
A. apenninicum differs from A. aemulum (= Cannosphaeropsis aemula Deflandre) in having processes typically terminating in a wide distal platform. It differs from A. apiculatum (= C. apiculata Cookson and Eisenack) for the high number of processes and the lack of trabecular spines. Deflandre's and Cookson and Eisenack's species have been previously recorded only from the Upper Jurassic - Lower Cretaceous, with the exception of one specimen reported (but not figured) by Alberti (1961) from Senonian sediments of Germany. The difference in stratigraphic range is considered a further argument to justify the erection of the new species.
[Adnatosphaeridium apenninicum, Corradini, 1973, p. 163-164, pl.25, figs.4a-b; pl.36, figs.1a-b.
NOW Rigaudella. Originally Adnatosphaeridium, subsequently (and now) Rigaudella.
Holotype: Corradini, 1973, pl.25, figs.4a-b. ]
Locus typicus: Val Baganza, Parma, Italy
Stratum typicum: Campanian-Paleocene
Age: Campanian-?Paleocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Corradini, 1973, p. 164]:
Diagnosis:
Spherical to ovoidal central body with granular endophragm and smooth to fibrous periphragm. Processes solid, widening distally and interconnected by trabeculae. Apical archeopyle with zig-zag margin.
Description:
Solid or partially hollow intratabular processes arise from the periphragm, one or more in number on a single plate. From the wide base, often with a rootlike appearance, the processes expand distally in a broad, more or less fenestrate platform. Adjacent platforms are interconnected with thin and solid trabeculae having a variable cross-section. Few simple processes are thin, solid, usually paired, and fused proximally along 1/3 to 1/2 of their length. Distally they may have the platforms fused or may be irregularly branched. The branches being connected with distal margins of adjacent processes.
The processes reflect the tabulation 4', 6", 5-(6'''), 0-1p, 1''''.
Apical archeopyle with zig-zag margins, almost always present.
Dimensions:
Holotype: diameter of the central body 40 µm, length of the processes 20-28 µm.
Range: diameter of the central body 38(49)60 µm, length of the processes 20(23)30 µm.
Affinities:
A. apenninicum differs from A. aemulum (= Cannosphaeropsis aemula Deflandre) in having processes typically terminating in a wide distal platform. It differs from A. apiculatum (= C. apiculata Cookson and Eisenack) for the high number of processes and the lack of trabecular spines. Deflandre's and Cookson and Eisenack's species have been previously recorded only from the Upper Jurassic - Lower Cretaceous, with the exception of one specimen reported (but not figured) by Alberti (1961) from Senonian sediments of Germany. The difference in stratigraphic range is considered a further argument to justify the erection of the new species.