CHEMICAL-COMPOSITION AND ULTRASTRUCTURE OF FOSSIL AND EXTANT SALVINIALEAN MICROSPORE MASSULAE AND MEGASPORES

The resistant remains of salvinialean microspore massulae and megaspor es have been analyzed using scanning and transmission electron microsc opy and Curie-point pyrolysis. The results show a selective enrichment of specific tissues in the fossil samples. The resistant compound, sp oropollenin, in these fossil remains, is shown to consist of an oxygen ated aromatic, and an aliphatic moiety. The latter is selectively enri ched during diagenesis and upon oxidation. The organic matter of the e xtant samples is dominated by compounds which, during diagenesis, are selectively removed. The morphologically distinct megaspores and micro spores are chemically comparable. Furthermore, although the genera stu died are strongly distinctive in morphology and ultrastructure, the va riation in their chemistry is too small to use for chemotaxonomy.