Fish vertebrae fragmentation: experimental approach to identify breakage patterning due to compression

Abstract

Vertebrae represent a substantial fraction of fish remains recovered from archaeological sites. The fragility of these skeletal elements under mechanical efforts causes deformations and breakage due to sediment compression or trampling that cannot be well interpreted without experimental work. We analyse experimentally the fragmentation that occurs by vertical efforts using an uniaxial compression equipment (10N to 5000 N) on the sagittal planes from 86 modern fish vertebrae of Sciaenid, Salmonidae, Gadidae and Merlucciidae. Dry, fresh and hydrated specimens were included in the experimentation. Fragmentation was categorised as mild, extensive or total. Experimental results show that extensive fragmentation is most frequent. Total fragmentation was registered only in dry vertebrae. Fragmentation patterns fish vertebrae from Cueva Nerja (25,000–5,000 YBP, Spain) and El Americano II (ca. 7,000 YBP, Argentina) archaeological sites were compared to the experimental results. Fragmentation morphology identified in Cueva Nerja corresponds to extensive and mild fragmentation; also, mild and extensive fragmentation stages occurred in similar proportion in the El Americano II archaeological sample.