A warm and humid paleoecological context for the Neanderthal mountain settlement at the Navalmaíllo rockshelter (Iberian Central System, Madrid)

Neanderthals have been claimed to have had a selective adaptation to rugged, wooded landscapes that would have partially compensate their high basal metabolic rate and locomotor energetic costs through reducing search time and increasing diet breadth. The archaeological site of the Navalmaíllo rockshelter (Pinilla del Valle, Madrid), located in a mountain environment in central Iberian Peninsula, has been interpreted as a repeated short-term occupation hunting camp by Neanderthal groups, mainly focused on primary access to large bovids and cervids. Navalmaíllo rockshelter has also furnished fish, toads, frogs, tortoises, lizards and snakes remains. This association of amphibians and reptiles suggests a much warmer climate (þ 2.8ºC) for layer F than at present, with similar temperatures during the summer but higher temperatures throughout the remaining months. Rainfall was slightly more abundant (þ180.6 mm) than today, with a more contrasted regime during the year, with rainier winters and drier summers. A two-month period of aridity is observed during summer, representing a similar duration to present-day climatic conditions. Reconstructed landscapes are mainly constituted by open areas with dry grassland and rocky or stony areas, evolving laterally to humid meadows, probably close to the aquatic and peri-aquatic areas, such as rivers or ponds with riverside vegetation. Woodland environments are lso well represented around the site, with medium scrublands to forest formations. Fish complete this reconstruction by documenting the presence of a pre-mountain well-developed river system characterized by relatively cold, permanent, oxygen-rich, and running waters. Such reconstruction is in disagreement with previous pollen interpretation for Layer F that suggested a very open and cold environment. Our new interpretation suggests that the Neanderthal occupation of the Navalmaíllo rockshelter occurred during a somewhat temperate and humid period, probably within the later