Until recently, evidence of Neanderthal cave use in the Algarve (Southern Portugal) came only from the site of Ibn Ammar. Over the last couple of years, archaeological excavations inside another cave, Gruta da Companheira, yielded Mousterian stone tools associated with possible human fossils. The discovery of this assemblage is groundbreaking because it may contribute to enlighten the Neanderthal/cave relationship and explain the dearth of similar sites in the Algarve. Gruta da Companheira, however, is a complex karst system, which was partly destroyed during its accidental discovery. As result, the original entrance of the cave remains unknown, and it is unclear how sediments, archaeological materials and Neanderthals accessed the site. To tackle these issues, we combined geomorphological observations with speleological, Electrical Resistivity Tomography (ERT) and Ground‐Penetrating Radar (GPR) prospections. Our data indicate that Gruta da Companheira was probably accessed from the hilltop through a sub‐vertical entrance. Additionally, our results suggest the existence of yet unexplored shallower cavities connected with the already known passages of Gruta da Companheira. These results will guide the opening of new excavation areas at the site. The limestone bedrock hosting Gruta da Companheira has been extensively dissolved by karst processes. Therefore, it is necessary to focus future research on the cave infillings to clarify whether Neanderthals exploited the cave's inner chambers or alternatively limited their occupations to the hilltop and geogenic processes reworked their materials into the endokarst system shortly after their stays. The deep karstification and partial collapse of the hill hosting Gruta da Companheira are common in limestone outcrops that occur throughout the Western Algarve. Poor visibility and poor accessibility of this karst area, densely covered with shrubby vegetation, are factors that need to be considered when addressing the scarcity of Middle Palaeolithic cave sites in this region.

The demographic history of Neanderthals is only partially understood. In Europe, some degree of genetic continuity has been shown from 120 thousand years ago (ka) onward despite the occurrence of multiple subsequent diversification events. While it has been proposed that a population turnover preceded the emergence of Late Neanderthals in Europe, the extent, timing, and geographic location of this event are currently unknown. Here, we report ten mitochondrial DNA sequences (mtDNAs) of Neanderthal individuals from six archaeological sites in Belgium, France, Germany and Serbia, and analyze them alongside 49 published mtDNAs. The integration of phylogenetic and molecular dating analyses with an extensive archaeological dataset enabled us to reconstruct temporal and spatial patterns in Neanderthal distribution. Remarkably, nearly all Late Neanderthal individuals across Europe belong to a single mtDNA lineage that diversified recently, confirming a large-scale genetic replacement. Our analyses date this diversification event to approximately 65 ka and suggest that it likely originated from a population refugium in southwestern France from which Neanderthals appear to have undergone a major range dispersal across Europe. In addition, we detect a sharp decline in the Neanderthal mtDNA effective population size beginning ~45 ka and reaching a minimum ~42 ka, shortly before their extinction. This study demonstrates that integrating molecular and archaeological datasets provides a more detailed understanding of the Late Neanderthal population’s history, and highlights the critical role of climate-driven refugia and subsequent range expansions in shaping the genetic landscape of Neanderthals through time.

After the Last Glacial Maximum, the Swabian and Franconian Jura (in SW and SE Germany, respectively) were repopulated by Magdalenian hunter-gatherers within the same communication network. However, while the Magdalenian settlement of the Swabian Jura dates to 17-14 ka cal BP, permanent Magdalenian occupations in the Franconian Jura date to 15-14 ka cal BP. In comparison with its western counterpart, the Franconian Jura was mostly excavated in the early days of archaeological research. Does this different chronology reflect the different history of research? Why did Magdalenian foragers establish permanent occupation in the Franconian Jura nearly 2 millennia after settling in Swabia, despite the fact these regions are only 150 km apart? To address these questions, we reinvestigated two sites in the Altmühl Valley with micromorphology and luminescence dating, namely Felsenhäusl-Kellerhöhle and Klausennische. Our data show that both sites have intact Pleistocene deposits. Among these, we identified sediments dating between 17 and 15 ka that show only rare lithic artifacts and microfeatures indicative of cold and arid conditions. Our work and published data suggest that the steady settlement of Magdalenian foragers in the Altmühl Valley starting 15 ka cal BP coincides with the end of this harsh period and the onset of cool and wetter environments. Data from the Swabian Jura demonstrated that in the Lone Valley, similar environments and Magdalenian occupations commenced earlier, starting 17 ka cal BP. Therefore, we propose that regional environments acted as a barrier against the dispersal of foragers in the Franconian Jura and determined its later Magdalenian occupation. Our research highlighted that different environments, taphonomic processes, and site uses probably coexisted across the German Jura. Therefore, it remains fundamental to expand the multisite data set proposed in this article to further test hypotheses about human/environment interaction in this region.