Resistant biomacromolecules in the fossil record¹

Abstract

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.

Micromorphology of outer exospore coatings inSelaginellamegaspores

“…A macromolecule like sporopollenin could well incorporate silica into its overall chemical structure, a view that is shared by Crang & May (1974) who stated that silica is likely to be an integrated compound of the pollen wall. Sporopollenin is believed to consist of long saturated aliphatic chains with varying degrees of aromatics (De Leeuw & Largeau, 1993;Bergen et al 1995;Wiermann, 2001;Dominguez et al 1999). Latest results suggest that long-chain (C24-28) highly aliphatic units form the core of this macromolecule, cross-linked with cinnamic acids (Bergen et al 2004).…”

Assessment of bog-body tissue preservation by pyrolysis-gas chromatography/mass spectrometry

“…Note: chemical structures indicate the tannin-derived pyrolysis products unique to each tanning agent. products attributed to collagen are derivatives of pyrimidine (4,14,27), however they cannot yet be attributed to any particular amino acid. Products with characteristic mass spectra in which m/z 94 is the major fragment ion (often base peak; 33,35,42,45) are also relatively abundant in the total pyrolysate (Fig.…”

Prediction of atmospheric δ¹³CO₂ using fossil plant tissues

“…We contend that a substrate comprising the contribution of multiple species and many individual plants is available within a few cubic centimeters of many terrestrial rocks and comprises the optimal substrate for d 13 C a reconstruction. In order to explore substrates that reflect little or no diagenesis, researchers have also explored the isolation and analysis of many types of specific structures and compounds exclusively associated with terrestrial land plants, including wood [Gröcke et al, 1999;van Bergen and Poole, 2002], cuticle Jahren, 2000, 2002;Jahren, 2002;Jahren et al, 2001Jahren et al, , 2005van Bergen et al, 1995], pollen [Jahren, 2004;Amundson et al, 1997;Hemming, 2000, 2001], rbcL gene DNA [Jahren et al, 2004b[Jahren et al, , 2006, and general ''biomarkers'' [Briggs et al, 2000;Pancost and Boot, 2004]. In each case, discrimination imparted during synthesis of specific plant components must be considered.…”