Resistant biomacromolecules in the fossil record

This paper reviews the occurrence of biomacromolecules in fossil plants and animals. The range of techniques used in their release, preparation, microscopy and chemical analysis is described, as is the role of decay experiments in their investigation. The major plant parts that include resistant macromolecules are discussed: algal cell walls, cuticles, spore and pollen walls, propagules, periderm, secondary xylem, and secretions. The chemistry of animal cuticles preserved in the fossil record is briefly considered; they may incorporate macromolecules of plant origin during diagenesis. Some future directions for research are outlined; characterization of sporopollenin, characterization of extant and extinct tissues and organs, chemosystematic investigations, taphonomic processes, investigation of biomacromolecules in animal fossils.