Taxonomy Online - Carboniferous spores part I - Species details


Species name
Vallatisporites vallatus Hacquebard, 1957

Description
Radial, trilete, camerate, cingulizonate miospores. Amb convexly rounded triangular. Trilete mark distinct to indistinct, sutures straight, extending to margin of inner body, accompanied by low, slightly elevated exoexinal folds which decrease in height towards the ends of the sutures. Height of folds in polar region approximately 2.5 µm. Exine two layered. Intexine thin, forms inner body conformable in outline with equatorial margin, surface laevigate. Exoexine closely adpressed to intexine over proximal and distal surface but separated at least to some extent in the equatorial plane where a well-developed narrow cuniculus is developed. Exoexine thin over proximal surface but slightly thicker distally and extended in the equatorial plane to form differentially thickened tapering cingulum. Cingulum consists of inner thicker zone that appears in part to overlap the equatorial margin of the inner body, up to 8 µm wide. In many specimens large numbers of small elongate internal vacuoles, separated by narrow walls, appear to be located within this portion of the cingulum. Individual vacuoles up to 5 µm in length. Outer part of cingulum thin and sometimes weakly radially striated. Distal exoexine bears a dense ornament of coni, grana and small spini, elements up to 3 µm in height and 2 µm in basal diameter. Elements normally discrete but some basal coalescence occurs. Ornament more sparsely distributed on the cingulum and at the equatorial margin is limited to small conate projections.

Other descriptions
Hacquebard, 1957, pp. 312–313, pl. 2, fig. 12. Staplin and Jansonius, 1964, p. 112, p1. 21, figs. 1–6. Higgs, Clayton and Keegan, 1988, pp. 80–81, pl. 16, figs. 19–20

Size
Overall equatorial diameter 50(59)70 µm. Diameter of spore body 35–44 µm

Remarks
Vallatisporites vallatus is distinguished from V. verrucosus Hacquebard 1957 by possessing a fine densely distributed ornament of coni, grana and infrequent spini that are less than 3 µm in height. V. pusillites (Kedo) Dolby & Neves 1960, differs by possessing an ornament of coarser coni and galeae 4–12 µm high with bases up to 6 µm in diameter.

Range
Late Devonian to Mississippian; Tournaisian, VI to CM biozones (Higgs et al., 1988)

Images

MPK 7325 MPK 7325 Figure 67a
Bedford Shale, Big Walnut Creek, Sunbury, Ohio, USA; Uppermost Devonian, Strunian, LL Biozone, Sample 5133, Specimen MPK 7325. Distal surface of exoexine over both body and cingulum bears densely distributed ornament of coni and small spinae; smaller elements occur on the cingulum. Specimen maximum dimension 61 µm.


MPK 7328 MPK 7328 Figure 67b
Horton Bluff Formation, Horton Bluff, Nova Scotia. Canada; Tournaisian, VV Biozone, AD Sub-biozone, Sample P6400, Specimen MPK 7328. Specimen maximum dimension 65 µm.