Taxonomy Online - Carboniferous spores part I - Species details


Species name
Lophozonotriletes malevkensis Naumova in litt. Kedo, 1963

Description
Radial, trilete, cingulate miospores. Amb rounded triangular to subcircular, inner body conformable in outline with the equatorial margin. Trilete mark distinct to indistinct, sutures simple, straight, extending to margin of the inner body, sometimes accompanied by low narrow labra. Intexine thin, laevigate, forms inner body conformable in outline with the equatorial margin. Exoexine closely adpressed to intexine over both proximal and distal surfaces but extended in the equatorial plane to form more or less undifferentiated uniform cingulum which occupies 20–35 % of the spore radius. Distal surface of exoexine ornamented in the region underlying the inner body with prominent rounded tubercles and verrucae, elements normally discrete but variable in size, height up to 6 µm and basal diameter varying between 3–15 µm. Elements commonly distributed in a concentric manner in the region adjacent to the body-cingulum boundary with a single, frequently larger, element developed in the distal polar region. Ornamentation absent from the majority of cingulum, margin smooth or minutely indented. Surface of exoexine between verrucose elements smooth or minutely granulate.

Other descriptions
Kedo, 1963, p. 87, pl. 10, figs. 240–241. Turnau, 1978, p. 9, pl. 3, fig. 8. Higgs, Clayton and Keegan, 1988, p. 67, pl. 8, figs. 11–13

Size
Overall equatorial diameter 32(42)52 µm

Remarks
Playford (1991) considered L. malevkensis and L. rarituberculatus (Luber) Kedo to be synonymous and to be more appropriately accommodated in Tumulispora Staplin & Jansonius 1964. In the present work the two taxa are maintained and retained in Lophozonotriletes, which is considered to be adequately differentiated from Tumulispora. Lophozonotriletes malevkensis and L. rarituberculatus differ in the following ways.
  1. L. malevkensis (32(42)52 µm; present study) is smaller than L. rarituberculatus (54(76)100 µm; present study).
  2. The ornamentation of verrucae and tubercles is smaller in L. malevkensis.
  3. The distribution of the verrucate ornament in L. malevkensis is restricted to the more polar regions of the distal surface and is largely absent from the cingulum resulting in a smooth equatorial margin. In L. rarituberculatus some of the ornament projects at the equator.

    Range
    Late Devonian to Mississippian; Strunian to Tournaisian; LN–PC biozones (Clayton et al., 1977)

    Images

    MPK 7459 MPK 7459 Figure 32a
    Imperial Formation, Richardson Mountains, Northwest Territories, Canada; Late Devonian, Strunian, LL Biozone, Sample 159G, Specimen MPK 7459. Specimen maximum dimension 51 µm.


    MPK 7463 MPK 7463 Figure 32b
    Imperial Formation, Richardson Mountains, Northwest Territories, Canada; Late Devonian, Strunian, LL Biozone, Sample 159G, Specimen MPK 7463. Specimen maximum dimension 49 µm.