IDENTIFICATION OF FOSSIL "FAKES" USING RARE EARTH ELEMENT(REE) SIGNATURES

Fossil “fakes”, like Piltdown Man or Archaeoraptor, made by combining bones from different species, may be difficult to detect by visual examination alone. We propose that analyses of REE in bones may aid in detection of some fakes as well as determining questions of fossil provenance. Our research indicates that REE concentrations in bones from an individual fossil are dependent on the osteological material type with: Cortical > Trabecular > Dentine > Enamel. Although REE concentrations vary according to bone material, the REE signatures (ratios of REE) in different bones of an individual fossil are identical. Bones from different parts of composited “fakes” could yield different REE signatures and REE concentration differences not consistent with derivation from a single individual. Therefore, REE signature variations can be used to determine some composite fossil “fakes”.

Differences in REE signatures have allowed identification of reworking or time averaging in vertebrate fossil assemblages. Although different fossils from a single quarry or locality will not have identical REE signatures, fossils from different chemical units or localities may be identified using statistical analysis. A database of REE signatures in fossils from chemically distinct units and localities may allow the provenance of a fossil to be identified. This may be important where there are questions about the locality or stratigraphic unit from which a fossil was obtained.

Future analysis of fossil “fakes” can be made rapidly and at a relatively low cost through the use of laser ablation ICP-MS (LAMP). Utilizing chemically distinct units based on REE signatures potentially reduces the complexity of determining fossil ‘fakes’ and fossil provenance and can prove to be a vital tool that complements existing methods.