Rodent gnawing over fresh, dry and thermo altered bones: an experimental study with archaeological implications at El Mirador Cave (Atapuerca, Spain)

Rodents gnaw bones to wear down their upper and lower incisors, which grow continuously. These gnawing marks are conspicuous and have long been identified in the fossil record. Archaeological taphonomy studies link modifications made by rodents to weathered and dried bones, while forensic taphonomy indicate that rodents also act on fresh corpses, consuming flesh and other tissues as well as fresh bones. Although these two approaches are complementary, there is a lack of information on how rodents modify bones in states other than dry or fresh. This experimental study aims to fill this gap in the research, describing modifications left by rodents (Mus musculus) to fresh, boiled, carbonised, calcined, and dry bones. Our results indicate that rodents modify bones regardless of their state, and that the most intense gnawing occurs on bones containing fat. During the study, the pedestalling phenomena emerged as a characteristic modification produced only on fresh and boiled samples. We applied our results to the study of the human remains from El Mirador Cave (Atapuerca, Spain) and identified pedestalling for the first time in the archaeological record. This modification may have been favoured by the presence of fatty bones laying exposed on the surface of the site.This research was supported by the CEX2019-000945-M,PRE2020-091974 through the María de Maeztu excellence accreditation (CEX2019-000945-M). IPHES research is framed within the CERCA Program/Generalitat de Catalunya http://www.iphes.cat/. The Ministry of Science, Innovation, and Universities (MICINN-FEDER) of the Spanish Government financed this research under project no. PGC2018-093925-B-C32. The AGAUR (project no. 2017 SGR-1040) and the URV (project no. Universitat Rovira i Virgili. 2018PFR-URV-B2-91) also provided funding. Funding for fieldwork came from the Cultural and Tourism Council of Castilla y León and the Atapuerca Foundation. The research of Francesc Marginedas was supported by the Spanish Ministry of Science and Innovation through and FPI Fellowship (PRE2020-091974). Antonio Rodríguez-Hidalgo’s research was supported by the Spanish Ministry of Science and Innovation through the ‘María de Maeztu’ excellence accreditation (CEX2019-000945-M; Ministerio de Ciencia, Innovacion y Universidades</#funding-source; Agència de Gestió d’Ajuts Universitaris i de Recerca</#funding-source; Spanish Ministry of Science and Innovation.With funding from the Spanish government through the "Severo Ochoa Center of Excellence" accreditation (CEX2019-000945-M).Peer reviewe