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Polysphaeridium fucosum
Polysphaeridium "?fucosum" (Valensi, 1955a, p.40; text-fig.2b) Davey and Williams, 1969, p.6. Holotype: Valensi, 1955a, text-fig.2b; Fauconnier and Masure, 2004, pl.52, figs.8–11. NOW Litosphaeridium. Originally Micrhystridium, subsequently Hystrichosphaeridium, thirdly Polysphaeridium?, fourthly Dapsilidinium?, fifthly (and now) Litosphaeridium. Questionable assignment: Davey and Williams (1969, p.6). Taxonomic junior synonyms: Hystrichosphaeridium tubiferum var. brevispinum, according to Below (1982c, p.29) — however, Lentin and Williams (1985, p.190) retained Hystrichosphaeridium tubiferum var. brevispinum (as Hystrichosphaeridium tubiferum subsp. brevispinum); Hystrichosphaeridium (as and now Litosphaeridium) arundum, according to Below (1982c, p.29) — however, Lentin and Williams (1985, p.227) retained Litosphaeridium arundum. This combination, as a questionable assignment, was not validly published in Davey and Williams (1966b, p.95), since these authors did not fully reference the basionym. Age: Late Cretaceous.
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Original description: [Valensi, 1955] (translated from French):
Holotype (unique): Cretaceous flint from Venesmes.
The ovoid shell has about twenty tube-like processes whose length is between a third and a half of its diameter. These tubes are hollow, of circular section, and their cavity does not seem to communicate with that of the shell; slightly widened at their base, they flare out a little at their end. The surface of the shell is granular and the color light brown.
The size is 20 to 24 μ for the shell alone, 7 to 10 μ for the processes and 30 to 35 μ for the total span.
Despite the absence of spines on the edges of the terminal funnel of the processes, Micrhystridium fucosum is undoubtedly a "Tubifer", but its small size and short processes distance it from Hystrichosphaeridium tubiferum and its more than double size, from Micrhystridium paulinae Val. of the Jurassic.
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Original description: [Valensi, 1955] (translated from French):
Holotype (unique): Cretaceous flint from Venesmes.
The ovoid shell has about twenty tube-like processes whose length is between a third and a half of its diameter. These tubes are hollow, of circular section, and their cavity does not seem to communicate with that of the shell; slightly widened at their base, they flare out a little at their end. The surface of the shell is granular and the color light brown.
The size is 20 to 24 μ for the shell alone, 7 to 10 μ for the processes and 30 to 35 μ for the total span.
Despite the absence of spines on the edges of the terminal funnel of the processes, Micrhystridium fucosum is undoubtedly a "Tubifer", but its small size and short processes distance it from Hystrichosphaeridium tubiferum and its more than double size, from Micrhystridium paulinae Val. of the Jurassic.