Origin of Pleistocene bonebeds at the GNL Quintero site (GNLQ1): New taphonomic evidence from a wetland mammal assemblage in the submerged landscapes of central Chile

Abstract

The underwater bonebed of GNL Quintero 1 (GNLQ1) site located nearshore at Quintero Bay on the central coast of Chile (32° S), offers an unparalleled view of submerged Late Pleistocene environments in the South American Pacific continental shelf. By updating the site taphonomic history, this study aims to refine the taxonomic descriptions and taphonomic interpretation of the assemblage through multivariate approaches and to elucidate the origins of these bonebed deposits. Taxonomically similar to other Late Pleistocene assemblages in Chile, GNLQ1 is the only submerged site along the South American Pacific coast that falls within the time window (<12 ka BP) of hypothesized early coastal occupations subsequently drowned by mid-Holocene transgressions, making it a key locality for evaluating how such deposits were formed. With this faunal analysis, we aim to describe the site formation dynamics of bonebeds associated with lakeshores and wetlands, as well as the impact of submarine conditions on their diagenetic patterns. Our updated results suggest that the assemblage formed almost entirely through non-anthropogenic processes, with no conclusive anthropogenic signature. Lastly, we discuss the relevance that these types of bonebeds hold for interpreting early human occupation in South America.