CHEMOTAXONOMY OF PROTOTAXITES AND EVIDENCE FOR POSSIBLE TERRESTRIAL ADAPTATION

Silicified and carbonized axes of Prototaxites are chemically analyzed by means of X-ray and organic-extraction techniques. The isolation and identification of cutin and suberin derivatives, i.e., .omega.-hydroxymonocarboxylic acids, suggest that Prototaxites was probably a terrestrial plant or an aquatic plant showing chemical adaptation to periods of desiccation. Normal saturated acids showing no odd or even carbon-number predominance, phenyl and naphthyl aromatic acids, and normal and aromatic dicarboxylic acids isolated from fossil material, are considered inconsistent with an algal biochemistry. The normal saturated fatty acids isolated from Parka, Pachytheca, Spongiophyton, Protosalvinia, Orestovia and Taeniocrada are compared with Prototaxites. Parka, Pachytheca, Spongiophyton and Orestovia parallel one another in their organic chemical constituents, while Protosalvinia, Taeniocrada and Prototaxites appear to have paralleled one another in their adaptation to a terrestrial habit.