Taxonomy Online - Carboniferous spores part I - Species details


Species name
Dictyotriletes fimbriatus (Winslow) Kaiser, 1970

Description
Radial, trilete, acamerate miospores. Amb rounded triangular to subcircular. Trilete mark distinct or obscured by ornamentation, sutures simple, straight, extending between half and two-thirds of spore radius. Exine bears characteristic reticulate ornament, muri present on proximal surface, reduced in height and density but commonly developed parallel to sutures of trilete mark. Muri 8–20 µm high and approximately 3 µm wide at base, with distinctive papillate crests. Muri enclose a variable number of large lumina up to 30 µm in diameter, variable in shape. Crests of muri deeply incised to about half their height to form blunt, slightly pointed or clavate papillae.

Other descriptions
Winslow, 1962, pp. 58–59, pl. 14, figs. 1–3, pl. 22, fig. 21. Kaiser, 1970, p. 95, pl. 19, figs. 4–6

Size
Overall equatorial diameter 69–115 µm. Diameter excluding ornament 52–80 µm

Remarks
The distinctive papillate crested muri forming the reticulate ornamentation of this species render it readily distinct from all other taxa assigned to this genus.

Range
Late Devonian (Strunian) to Mississsippian; Tournaisian; LL to HD Biozones (Higgs et al., 1988).

Images

MPK 7595 MPK 7595 Figure 16a
Bedford Shale, Big Walnut Creek, Sunbury, Ohio, USA; uppermost Devonian, Strunian, LL Biozone, Sample 5133, Specimen MPK 7595. Distal focus of specimen with relatively fine low muri enclosing smaller denser lumina. Trilete mark distinct, sutures simple, straight, extend at least three-quarters of spore radius with indication of muri-like structures running parallel to sutures. Specimen maximum dimension 73 µm.


MPK 7597 MPK 7597 Figure 16b
Bedford Shale, Big Walnut Creek, Sunbury, Ohio, USA; uppermost Devonian, Strunian, LL Biozone, Sample 5133, Specimen MPK 7597. Specimen showing papillate character of muri projecting at equatorial margin. Oblique compression in proximal focus. Specimen maximum dimension 78 µm.