Abstract
Extracts of six different types of fossil-bearing rocks of widely differing ages were shown by paper chromatography to contain amino acids. The presence of peptides in a lower Pleistocene siltstone was demonstrated by a biuret reaction. Similar extracts from seven rocks devoid of fossils contained neither amino acids nor peptides. The amino acids detected were: glycine, alanine, leucine, valine, glutamic acid, aspartic acid, proline and γ-aminobutyric acid, all of which are relatively stable to heat. Not all amino acids were present in each fossil. γ-Aminobutyric acid was present only in a trilobite limestone.