Taxonomy Online - Carboniferous spores part I - Species details


Species name
Endosporites zonalis (Loose) Knox, 1950

Description
Radial, trilete, camerate miospores. Amb of body and saccus circular to rounded triangular. Trilete mark distinct, sutures straight, extending to or almost to margin of inner body, accompanied by elevated flexuous folds of the exoexine which extend, decreasing in height, almost to the equatorial margin of the exoexinal body. Ends of elevated exoexinal folds connected laterally with narrow, fine, curvatural ridges that in proximo-distal compression are located, for much of their length coincident with the equatorial margin of the saccus, the exception being in the radial positions where minor invagination takes place. Intexine thinner than exoexine, forms inner body that may possess peripheral taper-point compression folds, indicating significant separation of the two exine layers. Exoexine thin, granulate with fine narrow limbus, forms saccus and is commonly extensively folded.

Other descriptions
Loose, 1934, p. 148, p. 17, fig. 5. Smith and Butterworth, 1967, pp. 272–273, pl. 22, figs. 3–4

Size
Overall equatorial diameter 61(82)104 µm. Diameter of inner body 33(50)61 µm. Ratio of inner body to saccus diameter 46(59)77 µm

Remarks
Almost identical to Endosporites globiformis (Ibrahim) Schopf, Wilson & Bentall except the ratio of the inner body to saccus is consistently larger and the exoexine appears slightly thicker.

Range
Pennsylvanian; Bashkirian to Moscovian [late Langsettian to Asturian] (Smith and Butterworth, 1967).

Images

MPK 7499 MPK 7499 Figure 18a
Argill Shell Bed, Argill Beck, Stainmore, Cumbria, England; Bashkirian [uppermost Langsettian], RA Biozone, Sample ASB, Specimen MPK 7499. Subcircular–rounded triangular camerate miospore with well-defined inner body occupying more than half of spore radius. Laesurae straight extending to body margin, partly obscured by compression fold. Exoexine laevigate, equatorial margin limbate. Note suggestion of curvaturae just inside equatorial margin at one radial apex. Specimen maximum dimension 94 µm.


MPK 7500 MPK 7500 Figure 18b
Argill Shell Bed, Argill Beck, Stainmore, Cumbria, England; Bashkirian [uppermost Langsettian], RA Biozone, Sample ASB, Specimen MPK 7500. Note trilete suture obscured by thickened elevated exoexinal folds that extend to margin of inner body. Specimen maximum dimension 90 µm.