Timing of the Middle-to-Upper Palaeolithic transition in the Iberian inland (Cardina-Salto do Boi, Côa Valley, Portugal)

Abstract

The timing of the Neanderthal-associated Middle Palaeolithic demise and a possible overlap with anatomically modern humans (AMH) in some regions of Eurasia continues to be debated. The Iberian Peninsula is considered a possible refuge zone for the last Neanderthals, but the chronology of the later Middle Palaeolithic record has undergone revision and has increased the debate on the timing of Neanderthal extinction. Here we report on a study of the 5-m-thick archaeological stratigraphy of the Cardina-Salto do Boi, an open-air site located in inland Iberia, from which optically stimulated luminescence (OSL) ages were obtained for Middle and Upper Palaeolithic occupations preserved in overbank alluvial deposits. Geomorphology, archaeostratigraphy, stone-tool evolution, and OSL dating support the persistence of Neanderthals after 41 ka in central Iberia; the transition between the Middle Palaeolithic material culture and the AMH-associated Aurignacian blade and bladelet production is estimated to lie between 34.0 ± 2.0 ka and 38.4 ± 1.9 ka. Our results demonstrate that investigations focusing on different geomorphological situations are necessary to overcome the current limitations of the evidence and to establish more consistent models for Neanderthal disappearance and AMH expansion in the Iberian Peninsula.

The early Aurignacian dispersal of modern humans into westernmost Eurasia

“…Modern humans may have encountered a few remnant Neanderthal groups but it appears that most of Iberia south of the Ebro was already depopulated ( 35 ). This pattern is evident in Portugal, where Middle Paleolithic end dates cluster at ∼45 to 42 ka at Foz do Enxarrique ( 30 ), Mira Nascente ( 53 ), Lapa do Picareiro, and Cardina ( 54 ), followed by a nearly total absence of evidence for Neanderthals on the landscape.…”

“…The Picareiro data confirm a rapid modern human dispersal across Iberia that opens up additional lines of inquiry, testable hypotheses, and explanatory scenarios for the Middle to Upper Paleolithic transition. First, the early Aurignacian arrival indicates a substantial time gap between the Picareiro record of Early Upper Paleolithic occupations and the rest of the region (27,54). This may reflect an expansion of small pioneer groups that did not leave a highly visible footprint due to low population density (55) or did not establish a permanent foothold in the region.…”

“…A critical aspect of dispersal would have been the development of cognitive maps to navigate unknown landscapes, and rivers are the easiest spatial features to follow ( 58 ). New optically-stimulated luminescence (OSL) ages for Cardina, an open-air site in the Douro drainage basin of northeast Portugal, show a long hiatus between the last Middle Paleolithic occupation ∼42.9 ka and the Evolved Aurignacian occupation ∼33.6 ka ( 54 ). The absence of an earlier Aurignacian occupation could rule out the Douro valley as a dispersal route, but the area may eventually yield supportive evidence.…”

Revisiting the Middle and Upper Palaeolithic archaeology of Gruta do Caldeirão (Tomar, Portugal)

“…However, application of the updated IntCal20 curve narrows that interval down and shifts it back by some five centuries, to 37.0–37.4 ka [ 41 , 100 ]. In the Côa Valley of Portugal, at the Cardina/Salto do Boi site, there is a long, consistently luminescence-dated Middle Palaeolithic sequence preserved in fluviatile sediments whose uppermost unit, GFU 5/UA 11, is chronologically bounded by a terminus post quem of 39.5 ± 1.8 ka (for GFU 5/UA 12 below) and a terminus ante quem of 33.6 ± 2.0 ka (for the earliest Upper Palaeolithic with Dufour bladelets in GFU 5/UA 10 above) [ 101 ]. Thus, both the Mula basin and the Côa Valley data are fully consistent with the Middle Palaeolithic persisting at Caldeirão beyond 39 ka.…”

The spatial patterning of Middle Palaeolithic human settlement in westernmost Iberia

“…On the one hand, the reinvestigation of previously known sites has exposed exceptional new data: from the systematic exploitation of aquatic resources and stone pine economy at Gruta da Figueira Brava during Marine Isotope Stage (MIS) 5 (Zilhão et al ., 2020) to the confirmation of the importance of small‐size prey and slow‐moving species in the Neanderthal diet (Carvalho et al ., 2018; Nabais and Zilhão, 2019). On the other hand, the discovery of new sites, such as Cobrinhos (Pereira et al ., 2019), Praia do Rei Cortiço, Mira Nascente (Haws et al ., 2010, 2011), or Gruta da Companheira, as well as the excavation of novel stratigraphical units in previously known sites such as Lapa do Picareiro (Benedetti et al ., 2019) and Cardina‐Salto do Boi (Aubry et al ., 2020), have allowed for expansion of the chrono‐cultural evidence of the Neanderthal presence in the region.…”