Although the exact habit and paleoecology of Sphenophyllum are not known, Batenburg (1981; 1982) suggested that the plants had prostrate rhizomes from which aerial axes arose. Many of the compression species have been reconstructed as scrambling understorey plants in which some of the leaves (or entire leafy branches) were modified for attachment

figure 10.25 Diagrammatic reconstruction of Lilpopia raci-borskii. (FromKerp, 1984.)
figure 10.26 Sphenophyllum cuneifolium, linear leaflet with foliar climber hook (Pennsylvanian). Bar = 200 pm. (Courtesy M. Barthel.)

(Bashforth and Zodrow, 2007). Sphenophyllum oblongi-folium and S. cuneifolium from the Pennsylvanian-Early Permian of France and Germany, produced specialized shoots with narrow, elongated leaves with a single vein that extended through the leaf tip to form climber hooks (FIG. 10.26), indicating a scrambling or climbing habit (Barthel, 1997; Galtier and Daviero, 1999; Barthel and Müller, 2006). Leaves modified into climber hooks have also been recorded for S. miravallis from the lower Stephanian (Upper Pennsylvanian) of the Saar Basin in Germany (Hetterscheid and Batenburg, 1984) and S. biarmicum from the Lower Permian of the central Cis-Urals (Naugolnykh, 2003). It has also been suggested that Sphenophyllum was a hydrophyte (or hygrophyte) in which portions of the vegetative plant body were permanently or temporarily submerged in water. Further information about the various hypotheses concerning the ecology of Sphenophyllum can be found in Shchegolev (1991), and a brief summary in Naugolnykh (2003).

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