Taxonomy Online - Carboniferous spores part I - Species details


Species name
Dictyotriletes muricatus (Kosanke) Smith & Butterworth, 1967

Description
Radial, trilete, acamerate miospores. Amb circular to rounded triangular. Trilete mark distinct or obscured by the ornamentation, sutures simple straight, extending between half and three-quarters of spore radius. Exine ornamented on entire distal surface and equatorial portion of proximal surface with muri which are up to 2 µm wide and 6–12 µm high. Muri enclose variable number of polygonal lumina which are of more or less uniform size on any individual but vary in size and number between individuals. Lumina vary in diameter up to 25 µm. Exine of lumina laevigate although infrequent small coni and spinae may occur.

Other descriptions
Kosanke, 1950, p. 27, pl. 4, fig. 7. Smith and Butterworth, 1967, pp. 197–198, pl. 11, figs. 25–26

Size
Overall equatorial diameter 68(83)97 µm

Remarks
Some specimens assigned to this species may possess lumina which are closely comparable in size and form to those of Reticulatisporites reticulatus (Ibrahim) Ibrahim 1933. The latter species is however readily distinguished by possessing a differentially thickened cingulum.

Range
Pennsylvanian; Bashkirian to Moscovian [Langsettian to early Bolsovian] (Smith and Butterworth, 1967)

Images

MPK 7583 MPK 7583 Figure 17a
Thin coal below Carbonicola pseudorobusta Shell Bed, Crag House Gill, Stainmore, Cumbria, England; Bashkirian [earliest Langsettian], SS Biozone, Sample CHG8, Specimen MPK 7583. Subcircular reticulate miospore. Trilete mark obscured by ornament but probably open and rays extending at least half spore radius. Exine ornamented with thin, high muri that enclose variable shaped lumina. Muri project at the equator to produce irregular, flange-like projection. Specimen maximum dimension 74 µm.


MPK 7592 MPK 7592 Figure 17b
Thin coal below Carbonicola pseudorobusta Shell Bed, Crag House Gill, Stainmore, Cumbria, England; Bashkirian [earliest Langsettian], SS Biozone, Sample CHG8, Specimen MPK 7592. Exine ornamented with narrow, relatively tall muri enclosing irregular lumina. Specimen maximum dimension 77 µm.