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Adnatosphaeridium robustum
Adnatosphaeridium robustum, (Morgenroth, 1966), De Coninck, 1975
Eaton, 1976, also effected the transfer of this species from Cannosphaeropsis O.Wetzel, 1933, to Adnatosphaeridium.
Holotype: Morgenroth 1966a: Pl. 4 Fig. 1
Locus typicus: Katharinenhof Fehmarn.
Stratum typicum: Lower Eocene (T2).
Age: Early Eocene
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Original description as Cannosphaeropsis robusta: [Morgenroth 1966a, p. 19] (Translation: GSC):
Diagnosis:
A species of the genus Cannosphaeropsis. The ellipsoidal capsule is uniformly covered with robust processes. The processes are distally connected to each other by strong cords (trabeculae). They are usually perforated by very fine holes.
Description:
The thin-walled, clearly ellipsoidal capsule has a very weakly granulate surface. From this arise relatively large solid processes that distally are connected with each other by strong cords. At the points of connection, the trabeculae are sometimes flattened (ribbon like). The processes and their distal connections are commonly perforated by very small holes. Some specimens show a large circular opening with a zigzag border which has obviously developed through the removal of a polar cap.
Affinities/Comparison:
In contrast to Cannosphaeropsis tutulosa Cookson and Eisenack 1960, the new species does not possess the distal splitting of the processes. Also, the capsule is not spherical but clearly ellipsoidal. The new species differs from Cannosphaeropsis filifera (Cookson and Eisenack) in not having free spines at the ramifications. Cannosphaeropsis filamentosa Cookson and Eisenack 1958 from the Upper Jurassic - apart from having a spherical capsule - possesses finer processes and more slender distal trabeculae.
Dimensions:
Capsule length: 44 µm (34/56 µm); capsule breadth: 39 µm (28/56 µm); specimen diameter: 95 µm (81/106 µm); pylome diameter approximately: 30 µm (20 measurements). Number of specimens examined: 22.
Eaton, 1976, also effected the transfer of this species from Cannosphaeropsis O.Wetzel, 1933, to Adnatosphaeridium.
Holotype: Morgenroth 1966a: Pl. 4 Fig. 1
Locus typicus: Katharinenhof Fehmarn.
Stratum typicum: Lower Eocene (T2).
Age: Early Eocene
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Original description as Cannosphaeropsis robusta: [Morgenroth 1966a, p. 19] (Translation: GSC):
Diagnosis:
A species of the genus Cannosphaeropsis. The ellipsoidal capsule is uniformly covered with robust processes. The processes are distally connected to each other by strong cords (trabeculae). They are usually perforated by very fine holes.
Description:
The thin-walled, clearly ellipsoidal capsule has a very weakly granulate surface. From this arise relatively large solid processes that distally are connected with each other by strong cords. At the points of connection, the trabeculae are sometimes flattened (ribbon like). The processes and their distal connections are commonly perforated by very small holes. Some specimens show a large circular opening with a zigzag border which has obviously developed through the removal of a polar cap.
Affinities/Comparison:
In contrast to Cannosphaeropsis tutulosa Cookson and Eisenack 1960, the new species does not possess the distal splitting of the processes. Also, the capsule is not spherical but clearly ellipsoidal. The new species differs from Cannosphaeropsis filifera (Cookson and Eisenack) in not having free spines at the ramifications. Cannosphaeropsis filamentosa Cookson and Eisenack 1958 from the Upper Jurassic - apart from having a spherical capsule - possesses finer processes and more slender distal trabeculae.
Dimensions:
Capsule length: 44 µm (34/56 µm); capsule breadth: 39 µm (28/56 µm); specimen diameter: 95 µm (81/106 µm); pylome diameter approximately: 30 µm (20 measurements). Number of specimens examined: 22.