Evaluation of summer exploitation of Otaria flavescens in coastal archaeological sites of Patagonia

BORELLA, F.; LHEUREUX, G.L.; GRANDI, F.

París

Conferencia; 11th International Council for ArchaeoZoology Conference; 2010

South American sea lion, Otaria flavescens, is one of the two species of Otariids commonly represented in the archaeological record of South American coastal sites. This taxon is characterized by breeding colonies during a reproductive season placed in selected littoral settings during summer. Thus, the finding of pups remains of O. flavescens in the Patagonian archaeological record has been used as seasonally marker frequently. However, the presence of pups remains do not assure the season of animal death without an accuracy determination of their age, being necessary to differentiate newborn individuals from the other age classes for inferring summer human occupations in the past. For this reason we carried out an osteometric study of the postcranial skeleton of modern young of the year sea lion puppies with sex and age known, the last estimated by dental replacement patterns (Crespo 1988). We measure 11 skeletal elements (long bones and innominate) in 30 individuals from the northern Patagonian coast, Argentina. The obtained values significatively correlates with age but not with the sex of pups, allowing us to use postcranial bone sizes as an accurate marker of sea lion pups ages and then a valuable tool for evaluate site seasonality.