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Cleistosphaeridium mediterraneum
Cleistosphaeridium mediterraneum, Corradini, 1973, p.137-138, pl.19, figs.5a-b; text-fig.4.
NOW Pervosphaeridium. Originally Cleistosphaeridium, subsequently Impletosphaeridium, thirdly (and now) Pervosphaeridium.
Holotype: Corradini, 1973, text-fig.4.
Locus typicus: Viano, Reggio Emilia, Italy
Stratum typicum: Senonian
Age: Senonian.
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Original description: [Corradini, 1973, p. 137-138]:
Diagnosis:
Test having subspherical to ovoidal central body with thick, punctate endophragm and striate periphragm.
Processes numerous, slender, solid, bearing extremely short distal spines.
Test surface divided into triangular or quadrangular fields by proximate crests.
Apical archeopyle with zig-zag margin.
Description:
The central body presents a more or less thin striate periphragm, trough which appears the punctate endophragm. Outer layer divided into triangular and quadrangular fields by proximate crests, reduced but always well evident.
The numerous (50-70), thin processes usually do not exceed half the diameter of the central body. Departing from the intersection of the crests, they taper weakly but gradually toward the apex were they feebly expand to extremely short spines. Proximal crests connecting adjacent processes are rarely present. No alignment of the processes is observed on the surface of the central body.
Archeopyle almost always present, suggesting apical position according to its clear zig-zag margin.
Dimensions:
Holotype: diameter of the central body 40x48 µm, length of the processes 14-20 µm.
Range: diameter of the central body 40-(44)-50x48-(50)-52 µm, length of the processes 12-(18)-24 µm.
Affinities:
Morphologically related to E. striolatum (Deflandre) and E. bifdum (Clarke & Verdier), Cleistosphaeridium mediterraneum differs in the lack of the typical processes and in the apical situation of the archeopyle.
NOW Pervosphaeridium. Originally Cleistosphaeridium, subsequently Impletosphaeridium, thirdly (and now) Pervosphaeridium.
Holotype: Corradini, 1973, text-fig.4.
Locus typicus: Viano, Reggio Emilia, Italy
Stratum typicum: Senonian
Age: Senonian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Corradini, 1973, p. 137-138]:
Diagnosis:
Test having subspherical to ovoidal central body with thick, punctate endophragm and striate periphragm.
Processes numerous, slender, solid, bearing extremely short distal spines.
Test surface divided into triangular or quadrangular fields by proximate crests.
Apical archeopyle with zig-zag margin.
Description:
The central body presents a more or less thin striate periphragm, trough which appears the punctate endophragm. Outer layer divided into triangular and quadrangular fields by proximate crests, reduced but always well evident.
The numerous (50-70), thin processes usually do not exceed half the diameter of the central body. Departing from the intersection of the crests, they taper weakly but gradually toward the apex were they feebly expand to extremely short spines. Proximal crests connecting adjacent processes are rarely present. No alignment of the processes is observed on the surface of the central body.
Archeopyle almost always present, suggesting apical position according to its clear zig-zag margin.
Dimensions:
Holotype: diameter of the central body 40x48 µm, length of the processes 14-20 µm.
Range: diameter of the central body 40-(44)-50x48-(50)-52 µm, length of the processes 12-(18)-24 µm.
Affinities:
Morphologically related to E. striolatum (Deflandre) and E. bifdum (Clarke & Verdier), Cleistosphaeridium mediterraneum differs in the lack of the typical processes and in the apical situation of the archeopyle.