Taxonomy Online - Carboniferous spores part I - Species details


Species name
Vallatisporites hystricosus (Winslow) Byvsheva 1985

Description
Radial, trilete, cinguli-camerate miospores. Amb rounded triangular to subcircular. Outline of inner body may be conformable with equatorial margin of spore or more circular resulting in the equatorial cinguli-zonate structure being wider in the radial positions. Trilete mark distinct, sutures straight, extending to margin of inner body, accompanied by elevated, flexuous folds of the exoexine, up to 4 µm in the polar region but decreasing in height and extending to the equatorial margin. Intexine thin, laevigate or finely infrapunctate, forming inner body. Exoexine closely adpressed to intexine except in the equatorial plane where a well developed cuniculus indicates limited separation. Exoexine extended in the equatorial plane to form bizonate cingulum consisting of a thinner, inner, extensively vacuolated zone with closely spaced radially orientated vacuoles separated by narrow walls, and a thicker, outer zone. Distal surface of exoexine bears galeate ornament of variable density; elements are largest and most densely distributed in the distal polar region and finer and less densely distributed towards the equatorial margin. Small, sharply pointed coni may be located in the spaces between the galeate elements. Individual galeae up to 10 µm high and 7 µm in basal diameter, consisting of a rounded basal boss surmounted by a sharply pointed, slender spina. Fusion between bases of adjacent elements forms irregular vermiculate elements with common spinose crests, particularly in the polar region. Numerous elements project at the equatorial margin.

Other descriptions
Winslow, 1962, pp. 41–42, pl. 18, fig. 5

Size
Overall equatorial diameter 46–84 µm

Remarks
Vallatisporites pusillites (Kedo) Dolby & Neves 1970 is similar in many respects to Cirratriradites hystricosus but is distinguished by possessing relatively finer ornamentation in which non-galeate elements are more common. It is probable that complete morphological gradation exists between the two species. Vallatisporites verrucosus Hacquebard 1957 is distinguished by possessing a verrucose ornament. Vallatisporites galearis Sullivan 1964 is smaller and possesses an ornament of galeae with cone-shaped rather than long, spinose terminations.

Range
Late Devonian to Mississippian; Strunian to Tournaisian (Winslow, 1962)

Images

MPK 7062 MPK 7062 Figure 66a
Sample 5133, Bedford Shale, Big Walnut Creek, Sudbury, Ohio, USA; Late Devonian, Strunian, LL Biozone, Specimen MPK 7062. Specimen maximum dimension 82 µm.


MPK 7063 MPK 7063 Figure 66b
Sample 5133, Bedford Shale, Big Walnut Creek, Sudbury, Ohio, USA; Late Devonian, Strunian, LL Biozone, Specimen MPK 7063. Distal focus. Note coarse galeate character of spinae that are most densely distributed over the polar part of the exine. In equatorial region, the ornamentation is less densely distributed and significantly smaller in size. Minor evidence of vacuolation of the cingulum. Specimen maximum dimension 84 µm.