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Pyxidinopsis crassimurata
Pyxidinopsis crassimurata Wilson, 1988
Holotype: Wilson, 1988, pl.17, fig.3a-c
Locus typicus: Waipawa Section, Hawkes Bay, New Zealand
Stratum typicum: Porangan, Middle Eocene
Original description: Wilson, 1988, p. 27
Cyst subspherical, of intermediate size, with a thick two layered wall (total thickness c. 4 µm) comprising a thin smooth inner layer and a thick spongy (tectate) microreticulate outer layer, both layers being in close contact. Surface ornament also comprises thin solid irregular ridges (height up to 3 µm) which are linked to form a coarse macroreticulum superimposed upon the microreticulate outer layer; ridges apparently not related to a paratabulation. Archeopyle precingular type P (3"" only) relatively large, elongate, pentagonal; operculum free. Paratabulation indicated by archeopyle only, although the macroreticulation has a somewhat polygonal pattern which resembles paraplates. Paracingulum and parasulcus not generally indicated. Dimensions: Holotype: length 54 µm, breadth 54 µm, total wall thickness 4 µm. Range: overall diameter 54(57)68 µm (n= 10).
Affinities:
Wilson, 1988, p. 26: Pyxidinopsis crassimurata is distinguished from other species of Pyxidinopsis in having a very thick wall, and in having a tectate surface sculpturing supplemented by an irregular macroreticulation formed by interconnecting ridges. The somewhat tectate nature of the surface is strongly reminiscent of the type species of Tectatodinum; however, the macroreticulation distinguishes this form from species of Tectatodinum, which are not reticulate.
Holotype: Wilson, 1988, pl.17, fig.3a-c
Locus typicus: Waipawa Section, Hawkes Bay, New Zealand
Stratum typicum: Porangan, Middle Eocene
Original description: Wilson, 1988, p. 27
Cyst subspherical, of intermediate size, with a thick two layered wall (total thickness c. 4 µm) comprising a thin smooth inner layer and a thick spongy (tectate) microreticulate outer layer, both layers being in close contact. Surface ornament also comprises thin solid irregular ridges (height up to 3 µm) which are linked to form a coarse macroreticulum superimposed upon the microreticulate outer layer; ridges apparently not related to a paratabulation. Archeopyle precingular type P (3"" only) relatively large, elongate, pentagonal; operculum free. Paratabulation indicated by archeopyle only, although the macroreticulation has a somewhat polygonal pattern which resembles paraplates. Paracingulum and parasulcus not generally indicated. Dimensions: Holotype: length 54 µm, breadth 54 µm, total wall thickness 4 µm. Range: overall diameter 54(57)68 µm (n= 10).
Affinities:
Wilson, 1988, p. 26: Pyxidinopsis crassimurata is distinguished from other species of Pyxidinopsis in having a very thick wall, and in having a tectate surface sculpturing supplemented by an irregular macroreticulation formed by interconnecting ridges. The somewhat tectate nature of the surface is strongly reminiscent of the type species of Tectatodinum; however, the macroreticulation distinguishes this form from species of Tectatodinum, which are not reticulate.