Remains of fill and floor? contextual taphonomy in a semi-subterranean structure in the hyperarid coast of the Atacama Desert, Chile

Architectural features and shell-matrix sites are one of the most challenging records for archaeological interpretation, due to their intricate stratification and complex depositional paths. In the hyperarid coast of the Atacama Desert, hunter-gatherer-fisher developed standardized stone-built architectural features mostly built on or directly related to shell-matrix deposits during the Late Archaic period (5700 – 4000 cal. years B.P.). These structures have been usually interpreted as sedentary villages or long-term campsites. These functional interpretations are based primarily upon intrasite variability, lacking systematic site formation analysis and chronostratigraphy. As a response to concerns arising from limited interpretive approaches, we propose a detailed taphonomic study of bone assemblages from a stone-built funerary structure of the Zapatero site (∼25°S, Taltal, Chile). We recorded macroscopic taphonomic modification features on mammal and avian bone remains (n = 1776) from five stratigraphic units within the structure. Our results attest that despite some similarities between strata, key differences in overall proportions suggest different taphonomic pathways. This variability within the sample is interpreted as a re-deposition of bone refuse from previous occupations as structural filling, intentionally deposited previous to the abandonment of the structure, therefore not directly related to the occupation of the architectonic feature. Finally, we highlight the role that relatively simple zooarchaeological and taphonomical comparisons intra-site, might shed light on exceptional site formation processes on short timescales, emphasizing why we must consider this sort of data even in low relative abundances in order to interpret taphonomic history pathways and depositional practices.