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Micrhystridium fucosum
Micrhystridium fucosum Valensi, 1955
Now Dapsilidinium?. Originally Micrhystridium, subsequently
Hystrichosphaeridium, thirdly Polysphaeridium?, fourthly (and now) Dapsilidinium?.
Tax. sr. synonym of Hystrichosphaeridium tubiferum ssp. brevispinum Davey and Williams, 1966, according to Below, 1982; however, Lentin and Williams, 1985 retained Hystrichosphaeridium tubiferum ssp. brevispinum as a separate taxon. Tax. sr. synonym of Litosphaeridium arundum (Eisenack and Cookson, 1960) Davey, 1979, according to Below, 1982; however, Lentin and Williams, 1985 retained Litosphaeridium arundum as a separate species.
Holotype: Valensi, 1955, text-fig.2b
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.
Now Dapsilidinium?. Originally Micrhystridium, subsequently
Hystrichosphaeridium, thirdly Polysphaeridium?, fourthly (and now) Dapsilidinium?.
Tax. sr. synonym of Hystrichosphaeridium tubiferum ssp. brevispinum Davey and Williams, 1966, according to Below, 1982; however, Lentin and Williams, 1985 retained Hystrichosphaeridium tubiferum ssp. brevispinum as a separate taxon. Tax. sr. synonym of Litosphaeridium arundum (Eisenack and Cookson, 1960) Davey, 1979, according to Below, 1982; however, Lentin and Williams, 1985 retained Litosphaeridium arundum as a separate species.
Holotype: Valensi, 1955, text-fig.2b
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.