Fatty acids in fossil fruits

Fatty acids extracted from six fruit of Nyssa fissilis from the Early Tertiary Brandon Lignite, Vermont, include mainly palmitic, palmitoleic, stearic, and oleic acids and a number of probable branched chain acids. Four unidentified ‘round fruit’ from the lignite contained the same acids in predominance. The two taxa were chemically indistinguishable because of wide intraspecific variation in percentage of each n-fatty acid present. ‘Fingerprint’ chromatograms of non-aromatic hydrocarbon extracts from two distinct taxa of fruit from an Eocene clay of Tennessee also showed no consistent interspecific differences. We conclude that degradation and removal of the seed food reserves and introduction of extraneous lipids limits the utility of fatty acids and hydrocarbons in chemosystematic study of fossil fruits at the species and genus levels.