Taxonomy Online - Carboniferous spores part I - Species details


Species name
Crassispora aculeata Neville, 1968

Description
Radial, trilete miospores. Amb subcircular to rounded triangular. Trilete mark distinct, sutures straight, extending to or nearly to the spore margin; accompanied by elevated flexuous folds that extend, decreasing in height, to the inner margin of the equatorial crassitude with which they fuse laterally. Apical papillae common in the intertectal areas. Exine laevigate or infrapunctate, thickened in the equatorial region to form ill-defined crassitude with weak inner margin. Crassitude invaginated in the radial positions where it fuses with folds accompanying trilete sutures to form clearly defined curvaturae which run just on the proximal side of the equatorial margin. Distal surface of exine and equatorial margin ornamented with spinae and rare coni; elements 1.5–15 µm in height, and 1–5.5 µm in basal diameter. Approximately 20 elements project at the equatorial margin, elements normally discrete and more or less constant in size on individual specimens.

Other descriptions
Neville, 1968, pp. 443–446, pl. 2, figs. 5–6

Size
Overall equatorial diameter 56(74)96 µm

Remarks
Crassispora maculosa (Knox) Sullivan 1964 is similar in size, but is distinguished by possessing an ornament of more densely distributed smaller coni.

Range
Mississippian; Visean to early Serpukhovian [Pendleian]; TC to NC Biozones (Clayton et al., 1977).

Images

MPK 7013 MPK 7013 Figure 11a
Shales below Hurlet Limestone, Hurlet Borehole, 130.68 m, Scotland; Mississippian, Visean, VF Biozone, Sample MPA 9158, Specimen MPK 7013. Subcircular trilete miospore with ill-defined equatorial crassitude. Ends of trilete sutures may merge into invaginated extension of ill-defined inner margin of equatorial crassitude. Well-developed spinose ornament over entire distal surface and more equatorial portion of proximal surface. Elements with bulbous bases and sharply pointed tops. Specimen maximum dimension 70 µm.


MPK 7014 MPK 7014 Figure 11b
Shales below Hurlet Limestone, Hurlet Borehole, 130.68 m, Scotland; Mississippian, Visean, VF Biozone. Sample MPA 9158, Specimen MPK 7014. Note elevated folds accompanying trilete mark. Specimen maximum dimension 76 µm.