Environmental context for the Late Pleistocene (MIS 3) transition from Neanderthals to early Modern Humans: Analysis of small mammals from La Güelga Cave, Asturias, northern Spain

Abstract

La Güelga Cave (Asturias, NW Spain) contains a stratigraphic succession dating from 47.2 ± 2.2 to 38.6 ± 0.5 cal kyr BP. Evidence of Mousterian, Châtelperronian and Aurignacian occupations in the succession documents the transition from Neanderthals to Early Modern Humans. To better understand the palaeoenvironmental context of this transition, we analyzed a rich small-mammal assemblage, comprising a minimum number of 2227 individuals and 20 taxa, in a high-resolution stratigraphic context, using the Bioclimatic Model, the Habitat Weighting Method, and biodiversity measures. Results identify a climate-cooling phase at the end of the Mousterian occupations (~45 ka), which transformed a mosaic of patchy forest and humid meadows into a more arid open landscape. Another cooling event, matching Heinrich stadial 4 (H4), coincided with the arrival of the Aurignacians (~39 ka). Comparison with regional and global records shows that the alternating cool-wet and arid events documented at La Güelga Cave are coeval with the advance and retreat of the Picos de Europa glaciers, and with global climatic events recorded in marine and ice cores. The impact of these environmental changes on the human cultural and biologic transitions is discussed.