Sphenopteris dicksonioides (GÖPP.) C.E. WEISS , 1881

Sphenopteris dicksonioides (GÖPP.) C.E. WEISS, 1881

Text-fig. 7b View Text-fig

1836 Aspidites dicksonioides GÖPP. , p. 361, pl. 28.

1881 Sphenopteris dicksonioides (GÖPP.) C.E. WEISS , p. 11, pl. 11, figs 65, 66.

1923 Sphenopteris dicksonioides (GÖPP.) C.E. WEISS ; Kidston, p. 73, pl. 18, fig. 1.

D e s c r i p t i o n. Small pinnate fragments, up to tripinnately divided. Antepenultimate rachises 2‒3 mm wide, bearing alternate penultimate pinnae at near to right-angles. Penultimate rachises spaced at 17 mm intervals, ca. 1 mm wide, bearing alternate ultimate pinnae at near to right-angles. Ultimate pinnae with up to 12 pairs of small, petiolate, subtriangular pinnules up to 4 mm long and 2 mm wide, with vaulted limb; each pinnule has three to five rounded, deeply separated lobes. Veins not clearly visible.

R e m a r k s. The type of the basionym of this species originated from the Serpukhovian of Upper Silesia. The only figured specimen from Scotland ( Kidston 1923: pl. 18, fig. 1) is a small fragment, whose affinities must be regarded as uncertain. Some authors have placed this species in Lyginopteris POTONIÉ auct. (i.e., Calymmotheca STUR ) (e.g., Patteisky 1957, Purkyňová 1970). However, no reproductive structures are known, nor any of the diagnostic features such as anastomosed rachial surface markings, and so the species has been retained here in Sphenopteris .

O c c u r r e n c e s. Limestone Coal Formation, between the Johnstone Shake Bed and the coal-bearing interval above the Black Metals Band.