Taxonomy Online - Carboniferous spores part I - Species details


Species name
Auroraspora macra Sullivan, 1968

Description
Radial, trilete, camerate miospores. Amb circular to subcircular, frequently irregular due to folding. Trilete mark distinct, sutures straight, extend at least two-thirds of the radius of the inner body, commonly accompanied by low thickened labra with irregular outer margins, which extend to the equatorial margin of spore. Intexine thin forming well defined inner body. Exoexine thin, variably separated from intexine, commonly folded, densely infrapunctate. Exoexine thickened in the equatorial plane to form limbus-like structure of variable width.

Other descriptions
Sullivan, 1968, pp. 124–125, pl. 27, figs. 6–10. Clayton, 1971, p. 580, pl. 1, fig. 3. Higgs et al., 1988, p. 69, pl. 9, figs 17–19

Size
Overall equatorial diameter 48(58)78 μm. Diameter of inner body 26(31)35 μm

Remarks
The distinctive thickened equatorial margin of the exoexine renders this species readily distinguishable from all other taxa assigned to the genus. Auroraspora solisortus Hoffmeister, Staplin & Malloy 1955 is larger, lacks the thickened exoexinal equatorial rim and possesses a radially oriented series of exoexinal folds. A. hyalina (Naumova) Streel in Becker et al. 1974 is slightly smaller in size and possesses a more filmy exoexine.

Range
Uppermost Devonian to Mississippian; Strunian to early Visean; LL to Pu biozones (Higgs et al., 1988)

Images

MPK 7475 MPK 7475 Figure 2a
Pinskey Gill Beds, Wygarth Gill Borehole, Ravenstonedale, Cumbria, England; Tournaisian, CM Biozone, Sample MPA 292, Specimen MPK 7475. Ovoid camerate miospore with extensively folded inner body surrounded by loose-fitting exoexine. Trilete mark indistinct, sutures open. Exoexine folded, finely infrapunctate, with ill-defined thickening at equatorial margin. Specimen maximum dimension 75 μm.


MPK 7476 MPK 7476 Figure 2b
Pinskey Gill Beds, Wygarth Gill Borehole, Ravenstonedale, Cumbria, England; Tournaisian, CM Biozone, Sample MPA 2699, Specimen MPK 7476. Specimen showing independent peripheral compression folds affecting the inner body and indicating separation of exine layers. Trilete mark distinct, sutures extending to equator of inner body. Exoexinal body with marked thickening in the equatorial region. Specimen maximum dimension 55 μm.