Evidence of paleoecological changes and Mousterian occupations at the Galería de las Estatuas site, Sierra de Atapuerca, northern Iberian plateau, Spain

Abstract

Here we present a new site in the Sierra de Atapuerca (Burgos, Spain): Galería de las Estatuas (GE), which provides new information about Mousterian occupations in the Iberian Plateau. The GE was an ancient entrance to the cave system, which is currently closed and sealed by a stalagmitic crust, below which a detritic sedimentary sequence of more than 2 m is found. This has been divided into five litostratigraphic units with a rich assemblage of faunal and lithic remains of clear Mousterian affinity. Radiocarbon dates provide minimum ages and suggest occupations older than 4514C ka BP. The palynological analysis detected a landscape change to increased tree coverage, which suggests that the sequence recorded a warming episode. The macromammal assemblage is composed of both ungulates (mainly red deer and equids) and carnivores. Taphonomic analysis reveals both anthropic, and to a lesser extent, carnivore activities. The GE was occupied by Neanderthals and also sporadically by carnivores. This new site broadens the information available regarding different human occupations at the Sierra de Atapuerca, which emphasizes the importance of this site-complex for understanding human evolution in Western Europe.

Single-grain OSL dating of the Middle Palaeolithic site of Galería de las Estatuas, Atapuerca (Burgos, Spain)

“…These test pits are located c. 18-20 m from the ancient cave entrance (Ortega, 2009). In GE-I, five lithostratigraphic units (LU) have been identified within the sedimentary sequence below the capping flowstone, while in GE-II, which has been less extensively excavated, only two LUs have currently been identified (Arsuaga et al, 2017). Archaeological and palaeontological remains have been recovered from all LUs, although the material recovered from LU1 and LU5 in pit GE-I was relatively scarce.…”

“…Sedimentological analyses of the LUs from both excavation pits indicate that the preserved sediment is allochthonous to the karst system (Aranburu et al, 2012; see Supplementary Information for further description of each LU). Transportation of these deposits into the cave interior is thought to have occurred via gravitational mass movement of water-saturated clays (i.e., debris flows), which simultaneously carried various proportions of clasts into the cavity (Arsuaga et al, 2017). The morphology of the gallery, as well as the position of the karstic infill deposits in relation to the cave entrance, suggest that the opening was a shallow ramp that allowed the progressive accumulation of fine-grain sediments and clasts under direct or indirect daylight, and ensured their subsequent transportation 20 m towards the cave interior during discrete runoff events (ramp inclination at the points of excavation is 5-8°).…”

“…All of the 14 C ages are close to the analytical limits of the technique; five out of the eight samples yield infinite uncalibrated age ranges, and all eight samples yield non-finite 95.4% calibrated age ranges. Consequently, Arsuaga et al (2017) cautiously interpreted these 14 C results as minimum ages and were only able to suggest that the archaeological accumulation at Galería de las Estatuas is likely of Late Pleistocene age. Given these problems, and the limited stratigraphic coverage of existing age control, there remains a need for a more comprehensive chronological study of the site.…”

“…In this regard, Galería de las Estatuas represents an important new archaeological sequence within the Sierra de Atapuerca complex. It is the first Middle Palaeolithic site (< 200 ka) to be systematically excavated within the endokarstic infill deposits of Atapuerca, and it is invaluable for providing improved insights into Neandertal occupational histories and subsistence/exploitation strategies in the region (Arsuaga et al, 2017).…”

“…The main archaeological and palaeoecological findings at Galería de las Estatuas have been summarised in Arsuaga et al (2017) and include: (i) a lithic assemblage composed of 499 objects showing clear Mousterian affinities (e.g., centripetal flake cores, side-scrapers, denticulates), with some products displaying characteristic Levallois débitage; (ii) a detailed pollen record revealing, from the base upwards, a change from an open environment and dry/cool climate to a phase of shrub expansion, followed by an incremental increase in wooded species, and a more humid and warmer climate at the top of the sequence; and (iii) an extensive micro-and macro-mammal faunal record, with the latter being dominated by ungulates and displaying abundant evidence of human modification (cut marks and anthropogenic breakage). The only chronological constraint available for this new site is a series of eight radiocarbon ( 14 C) ages obtained on faunal remains from levels LU1 and LU3, which range from 43.5 to > 46.3 14 C ka BP (uncalibrated), and a U-series age of ∼14 ka obtained for the base of a stalagmitic crust capping the entire sedimentary sequence (Martínez-Pillado et al, 2014;Arsuaga et al, 2017). All of the 14 C ages are close to the analytical limits of the technique; five out of the eight samples yield infinite uncalibrated age ranges, and all eight samples yield non-finite 95.4% calibrated age ranges.…”