Preservation of antigenic properties of macromolecules over 70 Myr

IT has been known for some time that many fossils still contain remnants of organic macromolecules, such as proteins and polysaccharides¹. Such macromolecules are often enclosed inside the mineralised tissues of fossils, well protected from outside influences. This close association of skeletal, mineral and macromolecular substances, which is also found in recent mineralised tissues, suggests that this organic material has been an important factor in the process of mineralisation and has deeply influenced the physical properties of the skeletons^2,3. It cannot be excluded however, that organic substances not involved in mineralisation can also be preserved in sedimentary rocks without much loss of their original structure, provided that they are well enclosed in the sediment. With this reservation in mind, characterisation of the structure of enclosed substances may yield valuable palaeobiochemical and diagenetical information.