Taxonomy Online - Carboniferous spores part I - Species details


Species name
Radiizonates aligerens (Knox) Staplin & Jansonius, 1964

Description
Radial, trilete, cingulizonate miospores. Amb rounded triangular to subcircular. Trilete mark indistinct, sutures when seen, simple, straight or flexuous, extending to, or almost to, inner body margin. Intexine thin, laevigate, forming poorly defined inner body that may show evidence of minor separation from the exoexine in the equatorial plane. Exoexine extended in the equatorial plane to form weakly bizonate cingulum consisting of a narrow darker inner zone which appears to overlap the equatorial margin of the inner body, particularly over the distal surface, and a wider thinner outer zone. Outer zone of cingulum bears a variable number of radially orientated elongate vacuoles that appear to be independently developed at two levels, presumably underlying both proximal and distal surfaces. Exoexine surface also bears numerous radially orientated striations and plications, which extend to the equatorial margin. Vacuoles separated by narrow walls. Distal polar exoexine may bear scattered grana or small verrucae.

Other descriptions
Knox, 1950, p. 329, pl. 19, fig. 288. Staplin and Jansonius, 1964, p. 106, p1. 18, figs. 23–28. Smith and Butterworth, 1967, p. 263, pl. 21, figs. 9–11

Size
Overall equatorial diameter 47(60)85 µm. Width of cingulum 14(19)27 µm

Range
Pennsylvanian; Bashkirian [Langsettian]; RA Biozone (Clayton et al., 1977)

Images

MPK 6989 MPK 6989 Figure 36a
Coal below Argill Shell Bed, Argill Beck, Stainmore, Cumbria, England; Bashkirian [late Langsettian], RA Biozone, Sample A17, Specimen MPK 6989. Subcircular cingulizonate miospores. Inner body small, less than half spore radius, trilete mark obscure. Cingulum weakly bizonate, consisting of narrow darker inner zone that appears to overlap the inner body, particularly over the distal surface and a wide thin outer zone. Outer zone bears a variable number of radially orientated striations that, in part, appear to be independently developed on both proximal and distal surfaces. Striations and plications extend to equatorial margin. Specimen maximum dimension 70 µm.


MPK 6993 MPK 6993 Figure 36b
Coal below Argill Shell Bed, Argill Beck, Stainmore, Cumbria, England; Bashkirian [late Langsettian], RA Biozone, Sample A17, Specimen MPK 6993. Note narrow row of pits at margin of the inner body suggesting that limited separation takes place in the equatorial region between intexine and exoexine. Specimen maximum dimension 85 µm.