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Corrudinium vermiculatum
Corrudinium vermiculatum (Wilson, 1988, p.26–27, pl.16, figs.1–2) Clowes and Wilson, 2006, p.406. Holotype: Wilson, 1988, pl.16, fig.2; Fensome et al., 1996, fig.2 — p.2429. Originally Ochetodinium, subsequently (and now) Corrudinium. Age: early Eocene.
Original description: Wilson, 1988, p. 27
Cyst fairly small, spherical to subspherical, with somewhat irregular vermiculate intratabular ornament and a finely reticulate surface. Paratabulation indistinct but apparently conforms to that of the genus. Hypocyst typically larger than epicyst. Autophragm thick (up to 5 µm) with a somewhat knobbly outline. Archeopyle trapezoidal to subtriangular, with a thickened margin; operculum free. Paracingulum fairly broad (up to 5 µm) poorly defined, especially on the ventral surface.
Dimensions: Holotype: length 56 µm, breadth 54 µm. Range: maximum diameter 46 (53) 61 µm (10 specimens).
Affinities:
Wilson, 1988, p. 27: The species differs from the type species 0. romanum in having a typically vermiculate intratabular ornamentation, an apparently thicker wall, and in having less well-defined paratabulation. It also resembles some species of Corrudinium but differs in having relatively prominent intratabular ornamentation.
Remarks (Clowes and Wilson, 2006)
Although this species does not closely resemble Corrudinium incompositum, and there is no conclusive stratigraphic
or paleogeographic relationship between it and any of the other species of Corrudinium considered herein, neither
does it possess the characteristic "highly perforate parasutural elevations of [the] autophragm" exhibited by Ochetodinium (Damassa 1979, p. 833). For the present we believe that the species is best placed in Corrudinium, a possibility hinted at in the original description, where it is noted that it differs from some species of Corrudinium only in "having relatively prominent intratabular ornamentation" (Wilson 1988, p. 27). The species also bears some similarity to Pyxidinopsis, particularly the species with which it shares a small, trapezoidal to subtriangular archeopyle (e.g., Fig. 5F,I), but differs in exhibiting traces of paratabulation, which are lacking in Pyxidinopsis.
Original description: Wilson, 1988, p. 27
Cyst fairly small, spherical to subspherical, with somewhat irregular vermiculate intratabular ornament and a finely reticulate surface. Paratabulation indistinct but apparently conforms to that of the genus. Hypocyst typically larger than epicyst. Autophragm thick (up to 5 µm) with a somewhat knobbly outline. Archeopyle trapezoidal to subtriangular, with a thickened margin; operculum free. Paracingulum fairly broad (up to 5 µm) poorly defined, especially on the ventral surface.
Dimensions: Holotype: length 56 µm, breadth 54 µm. Range: maximum diameter 46 (53) 61 µm (10 specimens).
Affinities:
Wilson, 1988, p. 27: The species differs from the type species 0. romanum in having a typically vermiculate intratabular ornamentation, an apparently thicker wall, and in having less well-defined paratabulation. It also resembles some species of Corrudinium but differs in having relatively prominent intratabular ornamentation.
Remarks (Clowes and Wilson, 2006)
Although this species does not closely resemble Corrudinium incompositum, and there is no conclusive stratigraphic
or paleogeographic relationship between it and any of the other species of Corrudinium considered herein, neither
does it possess the characteristic "highly perforate parasutural elevations of [the] autophragm" exhibited by Ochetodinium (Damassa 1979, p. 833). For the present we believe that the species is best placed in Corrudinium, a possibility hinted at in the original description, where it is noted that it differs from some species of Corrudinium only in "having relatively prominent intratabular ornamentation" (Wilson 1988, p. 27). The species also bears some similarity to Pyxidinopsis, particularly the species with which it shares a small, trapezoidal to subtriangular archeopyle (e.g., Fig. 5F,I), but differs in exhibiting traces of paratabulation, which are lacking in Pyxidinopsis.