Collagen and a cellulose-like substance in fossil dentine and bone.

Abstract

THE first direct evidence that certain organic components are retained in the fossil remains of vertebrates comes from the analysis by paper chromatography of specimens of Dinichthys of Middle Devonian age (380 million years old)1. This work has shown that degradation products of collagen can still be recognized. More recently2, it has been demonstrated that fossil dentine and bone-like tissues in Devonian ostracoderms are capable of being decalcified and sectioned on a microtome. Further work at the Royal Dental Hospital, London, using normal histological staining techniques, has now indicated the presence of polysaccharides as well as collagen in the dentine and bone-like tissue of the ostracoderms. Using fossil bone belonging to a bison from the most recent Ice Age, and to Dremotherium from the Miocene (25 million years old), electron microscope photographs have been obtained at the Nuffield Orthopaedic Centre, Oxford, showing collagen fibrils and the intact walls of canaliculi3. Furthermore, X-ray diffraction of the same material has established that it is the tubular form of collagen that is present.