Detection of bone preservation in archaeological and fossil samples

Abstract

Several methods for assessing the preservation of the organic and inorganic components of bone are discussed. Aspects of bone composition (i.e. specific trace element concentrations and stable isotope ratios) provide information on diet and health status in prehistoric and fossil humans. Such information is valuable in understanding the evolution of human adaptation but, prior to the analysis of bone, it is necessary to ensure that the biological signature has not been erased during burial or following excavation. The purpose of the present study was to provide relatively quick methods of scanning sets of bones in order to eliminate ones that are not appropriate for analysis. We present the results of powder X-ray diffractometry and a survey of thin sections of human bones recovered from a coastal site in Georgia (U.S.A.) to assess the preservation of biogenic bone mineral and histological structure. Those bone samples which displayed a lack of histological structure also showed X-ray diffraction patterns which deviated markedly from that of fresh bone. We conclude that a survey of thin sections of a small number of samples in any skeletal population is a rapid, dependable means of eliminating bone which has been altered diagenetically. We also present the results of amino acid analysis of "gelatin" collected using two different methods of extracting the organic component in bone. The "gelatin" which resulted from the demineralization of bone pieces in weak acid (1% HCI) consistently showed a pattern of amino acid composition similar to collagen. Conversely, the "gelatin" which resulted by hydrolyzing demineralized bone powder was unreliable in the retention of protein. Thus, use of the former method, rather than C to N ratios or % yield, appears to be the best means of ensuring analysis of material retaining a biological signature. At this point in time, we can identify bone samples appropriate for trace element and stable isotope analysis even though we cannot always identify the diagenetic process or agent involved.

Radiocarbon dates from the Grotte du Renne and Saint-Césaire support a Neandertal origin for the Châtelperronian

“…The criteria for determining whether the collagen was well-preserved and, therefore, could be radiocarbon dated was a collagen yield of above 1% and a C:N ratio between 2.9 and 3.6 (32)(33)(34)(35). After this determination, the collagen samples were graphitized.…”

Relationship of the cristallinity index (CI) with the age and content of F and CO₃ ions in vertebrate fossil samples

“…Como se puede apreciar, el IC es mayor en las muestras fósiles que en las actuales por su ganancia en flúor. Esto se confirma con lo observado por Lozinski (1973), Schoeninger et al (1989) y Newesely (1989, según los cuales, el incremento en flúor durante la diagénesis conduce a un aumento de la cristalinidad del apatito.…”

“…Los huesos fósiles muestran un incremento de la cristalinidad respecto a los actuales (Schoeninger et al, 1989;Sillen, 1989;Hedges & Millard, 1995;Sillen & Parkington, 1996;Elorza et al, 1999;LeeThorp, 2002;Reiche et al, 2002;Farlow & Argast, 2006) reflejándose en el aumento del tamaño del cristal, con la incorporación de flúor y la pérdida de carbonato en la estructura del apatito. Con la muerte y enterramiento del animal el material fosfático, componente de los huesos y dientes, empieza a sufrir transformaciones diagenéticas (Merino & Morales, 2006).…”

Bone Diagenesis and its Implication for Disease Diagnosis: The Relevance of Bone Microstructure Analysis for the Study of Past Human Remains

“…Moreover, it is useful to infer the role that bone abnormalities might play in the progression of diagenesis (Bianco & Ascenzi, 1993). Under polarized light, for example, the observation of "Maltese crosses" [an alternate pattern of light and dark bands (Schultz, 1997) that forms due to the presence of crystallized bone mineral oriented by the organization of the collagen fibers (Schoeninger et al, 1989)] is considered a good indicator of bone birefringence and of well-preserved lamellae in Haversian structures (von Hunnius et al, 2006). Furthermore, histology also allows differentiation between pathological lesions and pseudopathologies (Grupe & DresesWerringloer, 1993), which substantially reduces the amount of bias in the differential diagnosis of diseases.…”

“…crystallinity changes, porosity, and protein content), the histological study of bone integrity, simply or combined with other parameters, has been frequently used, not only to assess diagenetic changes (e.g., Hackett, 1981;Garland, 1987;Maat, 1993;NielsenMarsh & Hedges, 1999;Pfeiffer & Varney, 2000;Jackes et al, 2001;Turner-Walker & Syversen, 2002;Jans et al, 2004;Guarino et al, 2006;Turner-Walker & Jans, 2008;Abdel-Maksound, 2010;Hollund et al, 2012;Turner-Walker, 2012;Hollund et al, 2013), but also as a pre-screening tool to infer the degree of biomolecular (e.g., Hagelberg et al, 1991;Cipollaro et al, 1998;Zink et al, 2005), isotopic (e.g., Schoeninger et al, 1989;Balzer et al, 1997;Maurer et al, 2014) or paleopathological preservation (e.g., Stout, 1978;.…”