Taxonomy Online - Carboniferous spores part I - Species details


Species name
Grumosisporites verrucosus (Butterworth & Williams) Smith & Butterworth, 1967

Description
Radial, trilete, camerate miospores. Amb circular to rounded-triangular with undulating equatorial margin. Trilete mark distinct, sutures straight, simple or with low, narrow, thickened labra; extending between two-thirds and the full spore radius. Intexine thin, forms irregular, extensively folded, inner body which is separated from the exoexine over a significant part of its surface. The two layers appear to be in contact at least at the contact areas. Exoexine 1–4 µm in thickness, ornamented with variably shaped verrucae which show basal coalescence to form short, irregular ridges. Elements densely distributed and separated by narrow channels of unornamented exoexine. Up to 30 elements project at the equator to produce undulating margin. Verrucae up to 3 µm high at equator. Ornament reduced or absent on the proximal surface.

Other descriptions
Butterworth and Williams, 1958, p. 369, pl. 2, figs. 2–3. Smith and Butterworth, 1967, pp. 232–233, pl. 18, figs. 1–6

Size
Overall equatorial diameter 42(53)64 µm

Remarks
Grumosisporites rufus (Butterworth & Williams) Smith & Butterworth 1967 possesses a thicker exoexine and a less regular ornamentation. Camptotriletes corrugatus (Ibrahim) Potonié & Kremp 1956 has a coarser ornament and lacks evidence of separation of the exine layers.

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

Images

MPK 7726 MPK 7726 Figure 22a
Coal above Lower Stonesdale Limestone, Coldkeld Beck, Stainmore, Cumbria, England; Serpukhovian [Pendleian], NC Biozone, Sample CB2l, Specimen MPK 7726. Well-developed ornament of verrucose elements fused into short irregularly orientated ridges. Exine thick, simulating narrow cingulum. Specimen maximum dimension 61 µm.


MPK 7727 MPK 7727 Figure 22b
Coal above Lower Stonesdale Limestone, Coldkeld Beck, Stainmore, Cumbria, England; Serpukhovian [Pendleian], NC Biozone, Sample CB2l, Specimen MPK 7727. Note simple trilete mark with laesurae extending between half to almost full spore radius. Specimen maximum dimension 62 µm.