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Charlesdowniea rotundata
From Fensome et al., 2019:
Charlesdowniea ?rotundata (Châteauneuf and Gruas-Cavagnetto, 1978, p.68–69, pl.3, fig.5) Williams et al., 2015, p.302. Holotype: Châteauneuf and Gruas-Cavagnetto, 1978, pl.3, fig.5. Originally Kisselevia coleothrypta subsp. rotundata, subsequently Charlesdowniea coleothrypta subsp. rotundata, thirdly (and now) Charlesdowniea? rotundata. Questionable assignment: Williams et al. (2015, p.302). Age: Middle Eocene (Lutetian–Bartonian).
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Original description, Châteauneuf and Gruas-Cavagnetto, 1978: Kisselevia coleothrypta subsp. rotundata subsp.nov. [translation pkb 2025)]
Origin of the subspecies name from Latin rotundus: round, rounded: characteristic of the shape of this subspecies.
Diagnosis: pentagonal shape, very rounded, thin periphragm, very reduced horns, non-existent left antapical, continuous pericoele. Highly developed processes united in simulated complexes or plaque on the distal side by a finely perforated membrane, reproducing the shape of the underlying plaque.
Tabulation: 4’, 3a, 7’’, 5c, 5’’’, 2’’, 3-4 s.
Typical locality: Drancy survey (63 to 65 m), Paris basin, upper Cuisien (Laon clay level) France.
Holotype dimensions: 45 µm length, 45 µm width, 35/35 µm capsule. Process 2 to 4 µm in height.
Cotype dimensions: Extreme sizes observed 65/40 µm; 45/30 µm capsule. Process 2 to 6 µm.
Note: the shape of the periphragm is quite different from those of D. similis and W. articulata. The lateral horns are demarcated by slight protuberance of the periphragm from the general oval shape of the cyst. Sometimes they seem completely absent or are not visible. The intratabular processes are thin and aligned in rows parallel to the plate boundary. They are longer at the apical and lateral horns. The capsule is slightly grainy. The archeopyle is no different from that of the type species. This subspecies is therefore very clearly distinguished from other types of K. coleothrypta (pl. 3, fig. 2-4) by its very rounded, consequent, anatomical and lateral shape.
Stratigraphic distribution: Cuisian to Bartonian of the Paris basin.
Charlesdowniea ?rotundata (Châteauneuf and Gruas-Cavagnetto, 1978, p.68–69, pl.3, fig.5) Williams et al., 2015, p.302. Holotype: Châteauneuf and Gruas-Cavagnetto, 1978, pl.3, fig.5. Originally Kisselevia coleothrypta subsp. rotundata, subsequently Charlesdowniea coleothrypta subsp. rotundata, thirdly (and now) Charlesdowniea? rotundata. Questionable assignment: Williams et al. (2015, p.302). Age: Middle Eocene (Lutetian–Bartonian).
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Original description, Châteauneuf and Gruas-Cavagnetto, 1978: Kisselevia coleothrypta subsp. rotundata subsp.nov. [translation pkb 2025)]
Origin of the subspecies name from Latin rotundus: round, rounded: characteristic of the shape of this subspecies.
Diagnosis: pentagonal shape, very rounded, thin periphragm, very reduced horns, non-existent left antapical, continuous pericoele. Highly developed processes united in simulated complexes or plaque on the distal side by a finely perforated membrane, reproducing the shape of the underlying plaque.
Tabulation: 4’, 3a, 7’’, 5c, 5’’’, 2’’, 3-4 s.
Typical locality: Drancy survey (63 to 65 m), Paris basin, upper Cuisien (Laon clay level) France.
Holotype dimensions: 45 µm length, 45 µm width, 35/35 µm capsule. Process 2 to 4 µm in height.
Cotype dimensions: Extreme sizes observed 65/40 µm; 45/30 µm capsule. Process 2 to 6 µm.
Note: the shape of the periphragm is quite different from those of D. similis and W. articulata. The lateral horns are demarcated by slight protuberance of the periphragm from the general oval shape of the cyst. Sometimes they seem completely absent or are not visible. The intratabular processes are thin and aligned in rows parallel to the plate boundary. They are longer at the apical and lateral horns. The capsule is slightly grainy. The archeopyle is no different from that of the type species. This subspecies is therefore very clearly distinguished from other types of K. coleothrypta (pl. 3, fig. 2-4) by its very rounded, consequent, anatomical and lateral shape.
Stratigraphic distribution: Cuisian to Bartonian of the Paris basin.