BIOGEOCHEMICAL CHARACTERIZATION OF ICHTHYOSAUR BONES FROM HOLZMADEN (GERMANY, LIAS)

Holzmaden ''Laggerstatten'' is famous for its complete vertebrate skel etons. Geochemical and biochemical analyses were performed on ichthyos aur bones (Stenopterygius) and surrounding sediment to investigate the state of preservation of mineral and organic fractions. SEM observati ons and electron microprobe analyses show that fossil bones s. s. are slightly altered. The organic fraction is rather poorly preserved. Inf rared analyses indicate that the main bands characteristic of the orga nic matrix are absent or altered in fossil bones. Amino acid analyses do not reveal amino acids that could be attributable to the original o rganic matrix. In gel electrophoresis, both sediment and bone soluble extracts showed the same pattern with only faint bands. Tentative iden tifications of components with immunological assays using bovine colla gen and osteocalcin antibodies failed to reveal unambiguously these pr oteins. These results are discussed in relation to causal agents of fo ssilization occurring in the Holzmaden site.