Taxonomy Online - Carboniferous spores part I - Species details


Species name
Rotaspora knoxi Butterworth & Williams, 1958

Description
Radial, trilete, acamerate miospores. Amb subtriangular, with broadly rounded apices, to subcircular, outline of body more triangular. Trilete mark distinct; sutures straight, simple or with low narrow labra, extending between three-quarters and almost the full radius of the body. Exine laevigate. Zona widest (up to 6 µm) in the inter-radial position but significantly reduced at the apices. Zona normally bizonate with inner thicker zone of more or less uniform width, apparently overlapping margin of inner body at least on the distal surface. Outer thinner zone variable in width.

Other descriptions
Butterworth and Williams, 1958, p. 378, pl. 3, figs. 21–23. Sullivan and Marshall, 1966, p. 272, pl. 2, figs. 16–17. Smith and Butterworth, 1967, p. 228, pl. 15, figs. 15–17

Size
Overall equatorial diameter 26(32)44 µm

Remarks
Rotaspora fracta Schemel 1950, is distinguished by its smaller size, its concavely triangular spore body, its thinner exine and the tendency of its zona to be folded over the body in the radial positions.

Range
Mississipian; late Visean to Serpukhovian [Arnsbergian]; VF to TK biozones (Clayton et al., 1977).

Images

MPK 7802 MPK 7802 Figure 46a
Coal above Lower Stonesdale Limestone, Coldkeld Beck, Stainmore, Cumbria, England; Serpukhovian [Pendleian (E1)], NC Biozone. Sample YC, Specimen MPK 7802. Specimen with well-defined bizonate zona that is widest in the inter-radial region and reduced to almost absent in the radial positions. Trilete sutures extend almost to equatorial margin. Rays simple with triangular darkened region at the proximal pole. Specimen maximum dimension 30 µm.


MPK 7805 MPK 7805 Figure 46b
Coal above Lower Stonesdale Limestone, Coldkeld Beck, Stainmore, Cumbria, England; Serpukhovian [Pendleian (E1)], NC Biozone. Sample CB2 1, Specimen MPK 7805. Specimen maximum dimension 30 µm.