Taxonomy Online - Carboniferous spores part I - Species details


Species name
Crassispora trychera Neves & loannides, 1974

Description
Radial, trilete, variably camerate miospores, intexine probably attached proximally and separated to variable degrees over the distal surface. Amb subcircular, oval or irregular due to folding. Trilete mark usually distinct, sutures straight or sinuous, simple or accompanied by narrow flexuous folds, extending almost to the equatorial margin where they fuse laterally with curvaturae that are coincident for most of their length with the equatorial margin. Exoexine densely sculptured with coni and pilate elements, 1–3.5 µm high and 0.5–2.5 µm in width, with grana up to 1 µm in height and width, interspersed between elements. Distribution of ornament variable, sometimes dense but elsewhere sparse with unornamented areas. Equatorial margin thickened to form ill-defined crassitude with poorly delimited inner margin. Secondary compression folds commonly arranged in a concentric style close to the equatorial margin.

Other descriptions
Neves and Ioannides, 1974, p. 78, pl. 7, figs. 6–8

Size
Overall equatorial diameter 48(58)67 µm

Remarks
Endoculeospora gradzinskii Turnau 1975 possesses an ornament similar to that of Crassispora trychera but is distinctly camerate and has a small inner body. Crassispora kosankei (Potonié & Kremp) Bharadwaj is less extensively folded and possesses a more uniform conate ornament. Crassispora maculosa (Knox) Sullivan 1964 is larger with a thicker exine and heavier conate ornamentation.

Range
Mississippian; Tournaisian to early Visean; PC to Pu biozones (Clayton et al., 1977)

Images

MPK 8161 MPK 8161 Figure 14a
Cementstone Group, Bracken Bay, Heads of Ayr, Ayrshire; Mississippian, Tournaisian, CM Biozone, Sample MPA 29832, Specimen MPK 8161. Intexine forms well defined inner body. Trilete mark distinct, sutures obscured by low elevated folds that extend, decreasing in height, two-thirds of distance to equatorial margin where they fuse with low ridge like curvaturae. Entire distal surface, and that portion of proximal surface equatorial to the curvaturae, densely ornamented with coni and bacula that project at equatorial margin. Equatorial crassitude ill-defined. Specimen maximum dimension 65 µm.


MPK 8162 MPK 8162 Figure 14b
Pinskey Gill Beds, Wygarth Gill Borehole, Ravenstonedale, Cumbria, England; Mississippian, Tournaisian, CM Biozone, Sample MPA 302, Specimen MPK 8162. Proximal focus shows well-defined curvaturae devoid of ornamentation. Specimen maximum dimension 69 µm.