Taxonomy Online - Carboniferous spores part I - Species details


Species name
Grumosisporites varioreticulatus (Neves) Smith & Butterworth, 1967

Description
Radial, trilete, camerate miospores. Amb subcircular to oval. Trilete mark distinct, sometimes obscured, sutures straight, simple or with low, broad, thickened labra, extending between two-thirds and three-quarters of the spore radius. Intexine thin, forming irregular to sub-triangular inner body. Exoexine 2–3.5 µm thick, ornamented with often poorly defined reticulate sculpture. Muri narrow, up to 2 µm high enclosing lumina of irregular shape which may be up to 15 µm in diameter. Muri project at equatorial margin as low, broad-based conate projections. Reticulum best developed on distal surface and is most apparent at slightly elevated levels of focus.

Other descriptions
Neves, 1961, p. 8, pl. 2, figs. la–b. Smith and Butterworth, 1967, p. 232, pl. 17, figs. 8–10

Size
Overall equatorial diameter 70–110 µm

Remarks
The poorly defined reticulate ornament on the exoexine distinguishes G. varioreticulatus from other species assigned to the genus.

Range
Pennsylvanian; Bashkirian to Moscovian [Bolsovian]; KV to SL biozones (Clayton et al., 1977).

Images

MPK 7623 MPK 7623 Figure 21a
BGS Offshore Borehole 74/13, 18.07 m, Firth of Forth, Scotland; [Duckmantian], NJ Biozone, Sample CSA 1231, Specimen MPK 7623. Circular trilete miospore with undulate equatorial margin. Trilete mark distinct, sutures straight; length approximately three-quarters of spore radius, accompanied by low, ill-defined, thickened labra. Intexine separated from exoexine to form subcircular inner body. Intexine thin and probably folded. Exoexine ornamented with low muri forming reticulate pattern enclosing irregular lumina of variable size. Muri project at equator as low, cone-shaped projections. Specimen maximum dimension 83 µm.


MPK 7624 MPK 7624 Figure 21b
BGS Offshore Borehole 74/13, 18.07 m, Firth of Forth, Scotland; [Duckmantian], NJ Biozone, Sample CSA 1231, Specimen MPK 7624. Evidence of rounded triangular inner body. Exoexine ornamented with low muri that project at equator as low, conate projections and form ill-defined, reticulate pattern. Specimen maximum dimension 86 µm.