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Exochosphaeridium rhabdophorum
From Fensome et al., 2019:
Exochosphaeridium rhabdophorum (Valensi, 1955b, p.593, pl.3, fig.7) Masure in Fauconnier and Masure, 2004, p.164. Holotype: Valensi, 1955b, pl.3, fig.7; Fauconnier and Masure, 2004, pl.20, figs.10–11. Originally Hystrichosphaeridium,
subsequently Polysphaeridium?, thirdly Dapsilidinium?, fourthly (and now) Exochosphaeridium. Age: Late Cretaceous.
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Valensi, 1955:
Holotype: Cretaceous Venesmes Flint.
The spherical or slightly ellipsoidal shell bears a large number of processes whose length is about a third of its diameter. Simple and straight, these processes are shaped like short rods, barely widened at the base and of approximately constant caliber: they generally end in two short spines roughly perpendicular to their axis. Their cavity appears to be separate from that of the shell. Their insertions into this shell have, in optical section, the shape of an asterisk and appear regularly distributed: at the periphery and in the same plane, they are equidistant by about 5 µm. The shell is dark brown in color and its surface is slightly granular or finely punctuated. The size varies from 24 to 36 µm excluding the processes, which are 7 to 10 µm long, including the total wingspan. Between 39 and 49 µm.
This organism is often found mistreated by fossilization: the shell is deformed, its surface reticulated, the processes are enlarged and as if swollen or even spiraled. Hystrichosphaeridium rhabdophorum is very common in one of my flints where I counted 5 individuals in the field of a x6 objective and where it is even the most frequent after Hystrichosphaera furcata. The other flints contain a few examples. I found a fairly similar organism but with slightly longer processes in Cretaceous flints from the alluvial deposits of the Scine at Seine-Port.
Exochosphaeridium rhabdophorum (Valensi, 1955b, p.593, pl.3, fig.7) Masure in Fauconnier and Masure, 2004, p.164. Holotype: Valensi, 1955b, pl.3, fig.7; Fauconnier and Masure, 2004, pl.20, figs.10–11. Originally Hystrichosphaeridium,
subsequently Polysphaeridium?, thirdly Dapsilidinium?, fourthly (and now) Exochosphaeridium. Age: Late Cretaceous.
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Valensi, 1955:
Holotype: Cretaceous Venesmes Flint.
The spherical or slightly ellipsoidal shell bears a large number of processes whose length is about a third of its diameter. Simple and straight, these processes are shaped like short rods, barely widened at the base and of approximately constant caliber: they generally end in two short spines roughly perpendicular to their axis. Their cavity appears to be separate from that of the shell. Their insertions into this shell have, in optical section, the shape of an asterisk and appear regularly distributed: at the periphery and in the same plane, they are equidistant by about 5 µm. The shell is dark brown in color and its surface is slightly granular or finely punctuated. The size varies from 24 to 36 µm excluding the processes, which are 7 to 10 µm long, including the total wingspan. Between 39 and 49 µm.
This organism is often found mistreated by fossilization: the shell is deformed, its surface reticulated, the processes are enlarged and as if swollen or even spiraled. Hystrichosphaeridium rhabdophorum is very common in one of my flints where I counted 5 individuals in the field of a x6 objective and where it is even the most frequent after Hystrichosphaera furcata. The other flints contain a few examples. I found a fairly similar organism but with slightly longer processes in Cretaceous flints from the alluvial deposits of the Scine at Seine-Port.