Back
Rigaudella apenninica
Rigaudella apenninica (Corradini, 1973, p.163–164, pl.25, figs.4a–b; pl.36, figs.1a–b) Below, 1982b, p.148.
Holotype: Corradini, 1973, pl.25, figs.4a–b; Fauconnier and Masure, 2004, pl.68, figs.10–12. Originally Adnatosphaeridium, subsequently (and now) Rigaudella. Age: Campanian–?Paleocene.
Original diagnosis: Corradini, 1973, p. 164: Adnatosphaeridium apenninicum
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.
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.
Original description: Corradini, 1973, p. 164: Adnatosphaeridium apenninicum
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.
Affinities:
Corradini, 1973, p. 164: Adnatosphaeridium apenninicum
A. apenninicum differs from A. aemulum (= Cannosphaeropsis aemula Deflandre) in having proccsses 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.
Holotype: Corradini, 1973, pl.25, figs.4a–b; Fauconnier and Masure, 2004, pl.68, figs.10–12. Originally Adnatosphaeridium, subsequently (and now) Rigaudella. Age: Campanian–?Paleocene.
Original diagnosis: Corradini, 1973, p. 164: Adnatosphaeridium apenninicum
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.
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.
Original description: Corradini, 1973, p. 164: Adnatosphaeridium apenninicum
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.
Affinities:
Corradini, 1973, p. 164: Adnatosphaeridium apenninicum
A. apenninicum differs from A. aemulum (= Cannosphaeropsis aemula Deflandre) in having proccsses 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.