Taxonomy Online - Carboniferous spores part I - Species details


Species name
Lycospora pusilla (Ibrahim) Somers, 1972

Description
Radial, trilete, cingulizonate miospores. Amb circular to very broadly rounded triangular, outline smooth or finely indented. Trilete mark distinct, sutures simple or accompanied by low narrow flexuous exoexinal folds which extend decreasing in height to equatorial margin. Sutures extend to inner body margin. Intexine thin forming rounded triangular inner body. Exoexine thin, extended in the equatorial plane to form narrow bizonate cingulum consisting of a narrow, inner, darker zone which may in part overlap the equatorial margin of the inner body and a wider, thinner, outer zone. Total width of cingulum up to 4 µm. Distal surface of exoexine and cingulum finely granulate or in some cases conate. Folding common.

Other descriptions
Schopf, Wilson and Bentall, 1944, p. 54. Smith and Butterworth, 1967, pp. 251–252, pl. 20, figs. 10–12. Somers, 1972, pp. 66–70, pl. 1, figs. 5–33, pl. 2, figs. 3–20

Size
Overall equatorial diameter 20(27)40 µm

Remarks
Lycospora noctuina Butterworth & Williams 1958, is distinguished from L. pusilla by the presence of rugulae or verrucae on the distal surface. L. orbicula (Potonié & Kremp) Smith & Butterworth 1967, differs in possessing a very narrow cingulum. (See Somers, 1972, for detailed appraisal of L. pusilla and its relationships to other members of the genus.)

Range
Mississippian to ?Permian; Visean to ?Asselian; Pu to Granulatisporites confluens biozones (various sources)

Images

MPK 7631 MPK 7631 Figure 33a
Argill Shell Bed, Argill Beck, Stainmore, Cumbria, England; Bashkirian [uppermost Langsettian], RA Biozone, Sample ASB, Specimen MPK 7631. Rounded triangular cingulate miospore. Trilete mark distinct, sutures obscured by low elevated ridges or folds that extend to equatorial margin. Cingulum narrow, bizonate. Inner thicker zone of cingulum narrow and probably overlapping inner body margin on distal surface. Outer thinner zone slightly wider than inner thicker zone. Specimen maximum dimension 39 µm.


MPK 7633 MPK 7633 Figure 33b
Argill Shell Bed, Argill Beck, Stainmore, Cumbria, England; Bashkirian [uppermost Langsettian], RA Biozone, Sample ASB, Specimen MPK 7633. Specimen maximum dimension 40 µm.