“Multiple Microanalyses of a Sample from the Vinland Map" by Sommer et al (2017)

Sommer, D. V. P.; Mühlen Axelsson, K.; Collins, M. J.; Fiddyment, S.; Bredal-Jørgensen, J.; Simonsen, K. P.; Lauridsen, C. B.; Larsen, R., “Multiple Microanalyses of a Sample from the Vinland Map", Archaeometry 59(2) (2017) 287–301.
Doi:10.1111/arcm.12249 (Wiley Online Library, restricted access)

Abstract: 

A sample of the Vinland Map remaining from the radiocarbon dating was analysed with the purpose of identifying the post-1950 contaminant and establishing other evidence on the material composition, identity and condition. The analyses revealed that the parchment originates from a bovid and contains hair remnants. The fibre structure was in poor condition, with fragmented collagen fibres and a low hydrothermal stability. Greenish and reddish particles were observed on the parchment. The greenish particles were identified as basic copper(II) chloride, most probably atacamite, and the reddish particles as rust; that is, various iron(III) oxides. The extracted modern contaminant was identified as being naturally produced glycerol monostearate.

“Investigation of the recent microbial degradation of the skin of the Chinchorro mummies of Ancient Chile” by DeAraujo et al (2016)

DeAraujo, A.; Vasanthakumar, A.; Sepulveda, M.; Standen, V.; Arriaza, B.; Mitchell, R., “Investigation of the recent microbial degradation of the skin of the Chinchorro mummies of Ancient Chile”,  Journal of Cultural Heritage 22 (2016) 999–1005.

Doi:10.1016/j.culher.2015.11.004  (ScienceDirect, restricted access)

Abstract: 

Biodeterioration of cultural heritage artifacts due to microbial activity presents a significant challenge to conservators and museums around the World. A collection of Chinchorro mummies recovered from the Atacama Desert (the oldest artificial mummies ever found, dating back to 5050 B.C.E.) has been stored in the Universidad de Tarapacá, northern Chile. Over the past ten years, accelerated deterioration of some mummies has been documented. Blackening and exudation of some areas of their remaining skin is causing disfigurement of the mummies and poses a threat to the collection, also for mummies in situ exposed to the natural environment. This study was designed to provide a broad analysis of the skin microbiota of Chinchorro mummies and, investigate the relationship between the presence of microbes and the recent discoloration and biodegradation of the Chinchorro mummies’ skin. Microorganisms isolated from degraded Chinchorro mummy skin samples were similar, based on ribosomal RNA analysis, to bacteria found in the human skin microbiome (predominantly, Bacillus, Staphylococcus, and Methylococcus spp.) and commonly occurring fungi (predominantly, Penicillium and Aspergillus spp.). Some of these microorganisms were able to utilize collagen and/or keratin as the sole carbon source in vitro. We determined the activity of the collagenase/gelatinase enzymes produced by these microorganisms when grown on pig skin, which was used as a surrogate for human skin. The concentration of hydroxyproline, a measure of collagenous protein degradation by the microorganisms, increased with increasing relative humidity. We demonstrated that keratinolytic and collagenolytic opportunistic microorganisms were likely responsible for the recent degradation phenomenon.

“A whole mitochondria analysis of the Tyrolean Iceman’s leather provides insights into the animal sources of Copper Age clothing” by O’Sullivan et al (2016)

O’Sullivan, N. J.; Teasdale, M. D.; Mattiangeli, V.; Maixner, F.; Pinhasi, R.; Bradley, D. G.; Zink, A., “A whole mitochondria analysis of the Tyrolean Iceman’s leather provides insights into the animal sources of Copper Age clothing”, Scientific Reports 6 (2016) 31279. 

Doi:10.1038/srep31279 (Nature.com, open access)

Abstract: 

The attire of the Tyrolean Iceman, a 5,300-year-old natural mummy from the Ötzal Italian Alps, provides a surviving example of ancient manufacturing technologies. Research into his garments has however, been limited by ambiguity surrounding their source species. Here we present a targeted enrichment and sequencing of full mitochondrial genomes sampled from his clothes and quiver, which elucidates the species of production for nine fragments. Results indicate that the majority of the samples originate from domestic ungulate species (cattle, sheep and goat), whose recovered haplogroups are now at high frequency in today’s domestic populations. Intriguingly, the hat and quiver samples were produced from wild species, brown bear and roe deer respectively. Combined, these results suggest that Copper Age populations made considered choices of clothing material from both the wild and domestic populations available to them. Moreover, these results show the potential for the recovery of complete mitochondrial genomes from degraded prehistoric artefacts.