Hacquebard & Barss, 1957
Radial, trilete, cingulizonate miospores. Amb subcircular to rounded triangular, with straight to slightly concave or convex sides and rounded apices. Trilete mark distinct, sutures simple, straight; extending from two-thirds to almost the full body radius, frequently open. Intexine thin, laevigate, forming inner body. Exoexine normally closely adpressed to intexine, although minor separation may occur in the equatorial plane. Exoexine extended in the equatorial plane to form trizonate differentiated cingulum consisting of a broad, thickened inner zone of uniform thickness with a sharp outer margin, a thinner median zone which is commonly narrow, and a distinctive crenulate, outer, thickened zone which varies considerably in form and intensity of crenulation. Surface of exoexine laevigate.
Hacquebard and Barss, 1957, p. 38, pl. 5, figs. 8, 9
Overall equatorial diameter 58–86 µm
Mississippian, late Visean, [Asbian] NM Biozone (unpublished information)
MPK 7231 Figure 34a
Mattson Formation, south face Twisted Mountain, north-west of South Nahanni, Northwest Territories, Canada; Visean, MA Biozone (Playford, 1962), Sample MATT, Specimen MPK 7231. Proximal focus showing simple trilete sutures extending to margin of inner body. Note evidence of minor separation of intexine from exoexine in equatorial region adjacent to spore body margin.
Specimen maximum dimension 62 µm.
MPK 7244 Figure 34b
Mattson Formation, south face Twisted Mountain, north-west of South Nahanni, Northwest Territories, Canada; Visean, MA Biozone (Playford, 1962), Sample MATT, Specimen MPK 7244. Note coarse nature of segments in outer crenulate zone of cingulum.
Specimen maximum dimension 67 µm.