Scolecopteris cf. elegans Zenker, 1837

Scolecopteris cf. elegans Zenker, 1837 ( Fig. 8B View FIG )

This oblique transverse section of one pinnule also shows a lamina with palisade and spongy parenchyma but thin, more than 2 mm long, lateral extensions

FIG. 8. — Silicified plants from the Permian of Sardinia: A, Pecop- teris sp., transverse section of one vegetative pinnule showing thick lamina with palisade and aerenchyma mesophyll.Note the hair (arrow) attached near the lower extremity (SAR15B1T02); B, Scolecopteris cf. elegans Zenker , oblique transverse section

of one pinnule showing two synangia attached on the left side. Note the thick lamina similar to that of Pecopteris sp. ( A) but long thin pinnule extension on the right (SAR40C01); C, Scolecopteris cf. parvifolia Millay , part of a longitudinal section of one pinnule passing through several synangia. Note the relatively thin lamina, synangia borne on a short vascularised pedicel and solid tips of sporangia (SAR56AT02); D, E, Scolecopteris cf. alta Millay ; D, longitudinal section of a synangium showing the characteristic central column; E, transverse sections of synangia, the one above is through the basal part of the synangium, the other is through the distal region showing only four dehiscent sporangia (SAR01C2B02). Scale bars: 0.5 mm.

of the lamina enclosing the synangia. These fertile pinnules correspond to those shown in paradermal section on Figure 7F View FIG and there is good evidence that they were borne by a rachis of the Stewartiopteris sp. 2 type ( Fig. 7D View FIG ). Despite strong similarities in sporangia and synangiate organization with Scolecopteris oliveri , the sizes of the pinnules (about 2 mm broad and 4-6 mm long), synangia and sporangia (less than 1 mm long) are smaller than those of S. oliveri , according to measurements given by Scott (1932). Moreover,the lateral pinnule extensions are much more pronounced than in S. oliveri ; in fact, this Sardinian Scolecopteris rather resembles the organization and size of fertile pinnules of S. elegans Zenker, 1837 from the Lower Permian of Saxony ( Barthel & Weiss 1997) or of S. minor Hoskins, 1926 from the Upper Pennsylvanian of Illinois which belong to the Scolecopteris minor group defined by Millay (1979; 1997).