The strange case of Apigliano: early ‘fossilization’ of medieval bone in southern Italy

Abstract

The preservation of the osteological material at the medieval site of Apigliano, in southern Italy, is characterized by bones with highly crystalline, and altered, mineral phases. In addition to this, some material retains perfect histological preservation, with the exception of small microfissures present throughout this structure. Diagenetic porosity is indicative of collagen loss via chemical degradation. The levels of residual collagen in these bones are much lower than is predicted from simple models of gelatinization, and thus a more complex explanation for the state of preservation must be sought. Possible explanations for the rapid loss of bone collagen are considered, including a high-temperature event, the acceleration of hydrolysis due to liming and extreme wetting and drying cycles.

Characterisation of microbial attack on archaeological bone

“…This difference becomes more [20]. Indicated in grey in the HI=5 bar are the 'Apigliano style' samples [38].…”

“…Only 9% of the total sample could be considered well preserved. In 12% of the bones the characteristic 'Apigliano style degradation' [38] could be observed. Apigliano style degradation is characterised by highly crystalline and altered mineral phases, and loss of collagen, with no histological alteration except small micro-fissures.…”

Experimental chemical degradation compared to natural diagenetic alteration of collagen: implications for collagen quality indicators for stable isotope analysis

“…Here, the primary process is the hydrolysis of peptide bonds which leads to the formation of protein fragments that will be leached from the bone (Collins et al 1995). Contrary to the hypotheses on the stability of mineralized collagen Nielsen-Marsh et al 2000), a considerable loss of collagen can also occur in relatively young samples (younger than 1,000 years; Smith et al 2002Smith et al , 2007. Furthermore, isotopic ratios are not only obscured by diagenetically modified amino acid profiles, but also by contaminations with exogenous organic substances (with the extraction protocol not always removable).…”

Diagenesis and survival of osteocalcin in archaeological bone

“…Porosity was measured using mercury intrusion porosimetry assuming a contact angle of 163.1 after Joschek et al [20]. All the analyses were conducted in the same way as reported in Smith et al [30], with the exception that histological analysis of the three bison samples was made using polished thick sections of bone (approx 2 cm thick) embedded in resin and not thin sections, also cracking was not assessed on these samples.…”

“…These include well preserved bone (bone that remains relatively unaltered), 'fossilising' bone (with low collagen, levels and highly altered mineral, but no microbial attack, see [30]) and microbially attacked bone (in which alteration is less extreme than in 'fossilising' bone and microbially mediated).…”