Taphonomy into the beach: Experimental approach to bone modifications made by insects on an island (Gran Canaria, Canary Island, Spain).

Abstract

This study investigates the taphonomic processes affecting bones to understand the impact of insects on the decomposition activity. The experiment involved subjecting 5 unfleshed heads of pigs to different environmental conditions and contexts (buried and exposed). Nine different taxa of insects were identified here: flies puparia (Sarcophagidae, Calliphoridae [Chrysomia albiceps], Fanniidae and Muscidae), beetles (Dermestidae [Dermestes maculatus], Cleridae [Necrobia rufipes] and Hydrophilidae [Cercyon cf. arenarius]), ants (Formicidae [Tetramorium depressum]) and termites (Kalotermitidae [Cryptotermes brevis]). Taphonomic changes were observed on the bone surface with distinct patterns in buried and exposed elements. Location-dependent insect diversity and modifications were noted, with exposed specimens displaying more diversity than buried ones. Striations, U-shaped marks, and bone destruction were linked to specific taxa, including the possibility of osteophagic habits in species that have not previously exhibited these feeding behaviours. Other modifications, like perforations, are linked with the creation of pupal chambers of beetles when the bone does not have enough natural holes. In addition, evidence of termite activity, indicated by faecal pellets, suggested occasional bone destruction. The no presence of beetles in the coastal environment suggests that bones with the modifications made by these taxa could be transferred to this area after the process of meat decomposition. This is the first work on experimental archaeoentomology. Useful information is provided allowing a better understanding of the taphonomic processes in the coastal and inland archaeological sites.