Source Themes

Alternating carnivore and Neanderthal activities at Escoural Cave: insights from the taphonomic and machine learning analysis of leporid remains

Exploring the varied subsistence strategies and cave occupation patterns of Neanderthals is key to understanding their complex behaviors and ecological adaptations. Small game consumption, in particular, is considered a relevant indicator of their behavioral complexity. Rabbit assemblages from Pleistocene cave sites provide valuable insights into Neanderthal interactions with small prey and potential competition with carnivores. Here, we present the first detailed taphonomic analysis of faunal remains from Escoural Cave (Portugal), where a European rabbit (Oryctolagus cuniculus) assemblage was found alongside Middle Paleolithic stone tools and some macromammal remains. This study combines traditional zooarchaeological and taphonomic analysis of the rabbit remains with multivariate statistics and machine learning methods to establish the origin of the accumulation, and the implications for Neanderthal subsistence and cave use. Results from the taphonomic analysis show no evidence of human consumption but abundant evidence of small terrestrial carnivore activity, primarily from lynxes. This could indicate a sequential occurrence of Neanderthal and carnivore activities in the cave, with Neanderthal activities likely related to something other than rabbit consumption. Our study contributes to characterizing Iberian carnivore fossil accumulations and differentiating between faunal assemblages accumulated by carnivores and those by hominins. Additionally, we show that the use of machine learning analysis provides a robust and objective method for identifying and classifying taphonomic signatures, enhancing the accuracy and reliability of our interpretations. Future work will focus on analyzing additional faunal collections from both past and new excavations at Escoural, to test whether carnivores and Neanderthals focused on different prey types and how they shared the cave space.

Creating frames of reference for chert exploitation during the Late Pleistocene in Southwesternmost Iberia

Southwestern Iberia has played a key role in characterizing Late Pleistocene human ecodynamics. Among other aspects of human behavior, chert procurement and management studies in this region have received increasing attention in the past two decades, especially focusing on the sites showing repeated human occupation, such as the case of Vale Boi (Southern Portugal). However, these studies have been very limited in their geographical scope, and mostly focused on brief macroscopic descriptions of the raw materials. To further our knowledge of the relationship between regional availability of raw materials and its impact on human adaptations and mobility, a more detailed approach to characterizing geological sources is needed. This paper characterizes chert raw materials location, diversity, and availability in a geologically well-defined region of southern Portugal ‐ the Algarve. Through macroscopic and petrographic approaches, we provide a detailed characterization of geological chert sources to build a frame of reference for chert exploitation in the region. Our results show that there are four main chert formations in Algarve, and that despite the within-source variability, sufficient differences at macroscopic and petrographic levels are present to allow clear source attribution. These results provide a baseline for raw material studies in archaeological assemblages across southwestern Iberia, that will be essential to further characterize the dynamics of human behavior in some of the most important eco-cultural niches.

The sediment at the end of the tunnel: Geophysical research to locate the Pleistocene entrance of Gruta da Companheira (Algarve, Southern Portugal)

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.

SPIN enables high throughput species identification of archaeological bone by proteomics

Species determination based on genetic evidence is an indispensable tool in archaeology, forensics, ecology, and food authentication. Most available analytical approaches involve compromises with regard to the number of detectable species, high cost due to low throughput, or a labor-intensive manual process. Here, we introduce “Species by Proteome INvestigation” (SPIN), a shotgun proteomics workflow for analyzing archaeological bone capable of querying over 150 mammalian species by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Rapid peptide chromatography and data-independent acquisition (DIA) with throughput of 200 samples per day reduce expensive MS time, whereas streamlined sample preparation and automated data interpretation save labor costs. We confirm the successful classification of known reference bones, including domestic species and great apes, beyond the taxonomic resolution of the conventional peptide mass fingerprinting (PMF)-based Zooarchaeology by Mass Spectrometry (ZooMS) method. In a blinded study of degraded Iron-Age material from Scandinavia, SPIN produces reproducible results between replicates, which are consistent with morphological analysis. Finally, we demonstrate the high throughput capabilities of the method in a high-degradation context by analyzing more than two hundred Middle and Upper Palaeolithic bones from Southern European sites with late Neanderthal occupation. While this initial study is focused on modern and archaeological mammalian bone, SPIN will be open and expandable to other biological tissues and taxa.

No direct evidence for the presence of Nubian Levallois technology and its association with Neanderthals at Shukbah Cave

Blinkhorn et al.1 present a reanalysis of fossil and lithic material from Garrod’s 1928 excavation at Shukbah Cave, identifying the presence of Nubian Levallois cores and points in direct association with a Neanderthal molar. The authors argue that this demonstrates the Nubian reduction strategy forms a part of the wider Middle Palaeolithic lithic repertoire, therefore its role as a cultural marker for Homo sapiens population movements is invalid. We raise the following four major concerns: (1) we question the assumptions made by the authors about the integrity and homogeneity of the Layer D assemblage and (2) the implications of this for the association of the Neanderthal tooth with any specific component of the assemblage, (3) we challenge the authors’ attribution of lithic material to Nubian Levallois technology according to its strict definition, and (4) we argue that the comparative data presented derive from a biased sample of sites. These points critically undermine the article’s conclusion that Shukbah’s Neanderthals made Nubian cores and thus the argument that Neanderthals might have made Nubian technology elsewhere is unsubstantiated.

The spatial patterning of Middle Palaeolithic human settlement in westernmost Iberia

Currently available data on the Pleistocene human occupation of the westernmost territories of Iberia attest to the presence of Middle Palaeolithic industries from c. 240 ka cal bp until c. 37 ka cal bp. Previous studies focusing on this time frame have suggested that Middle Palaeolithic populations were highly mobile and predominately utilised locally available raw materials, with many cave and open-air sites being located near fluvial settings. Other than these observations, no specific studies have focused on exploring the factors influencing human site location choice during that time range. Employing statistical and GIS approaches, this paper provides an initial assessment of spatial patterning in human settlement during the Middle Palaeolithic of westernmost Iberia. Results show that site locations are biased towards lower elevations and riverine settings and suggest that distance to rivers might have impacted the diversity and specific types of lithic raw materials used at each site. These results help to shed light on the particularities of Neanderthal adaptations in a region regarded as a refugium during periods of unfavourable climate during the Middle Palaeolithic.

Late Glacial and Early Holocene human demographic responses to climatic and environmental change in Atlantic Iberia

Successive generations of hunter–gatherers of the Late Glacial and Early Holocene in Iberia had to contend with rapidly changing environments and climatic conditions. This constrained their economic resources and capacity for demographic growth. The Atlantic façade of Iberia was occupied throughout these times and witnessed very significant environmental transformations. Archaeology offers a perspective on how past human population ecologies changed in response to this scenario. Archaeological radiocarbon data are used here to reconstruct demographics of the region over the long term. We introduce various quantitative methods that allow us to develop palaeodemographic and spatio-temporal models of population growth and density, and compare our results to independent records of palaeoenvironmental and palaeodietary change, and growth rates derived from skeletal data. Our results demonstrate that late glacial population growth was stifled by the Younger Dryas stadial, but populations grew in size and density during the Early to Middle Holocene transition. This growth was fuelled in part by an increased dependence on marine and estuarine food sources, demonstrating how the environment was linked to demographic change via the resource base, and ultimately the carrying capacity of the environment.

The early Aurignacian dispersal of modern humans into westernmost Eurasia

Documenting the first appearance of modern humans in a given region is key to understanding the dispersal process and the replacement or assimilation of indigenous human populations such as the Neanderthals. The Iberian Peninsula was the last refuge of Neanderthal populations as modern humans advanced across Eurasia. Here we present evidence of an early Aurignacian occupation at Lapa do Picareiro in central Portugal. Diagnostic artifacts were found in a sealed stratigraphic layer dated 41.1 to 38.1 ka cal BP, documenting a modern human presence on the western margin of Iberia ∼5,000 years earlier than previously known. The data indicate a rapid modern human dispersal across southern Europe, reaching the westernmost edge where Neanderthals were thought to persist. The results support the notion of a mosaic process of modern human dispersal and replacement of indigenous Neanderthal populations.

Paleoenvironments and human adaptations during the Last Glacial Maximum in the Iberian Peninsula: A review

The Iberian Peninsula is considered one of the most well-suited regions in Europe to develop studies on the relationship between environmental changes and human adaptations across the Late Pleistocene. Due to its southwesternmost cul-de-sac position and eco-geographical diversity, Paleolithic Iberia was the stage of cyclical cultural/technological changes, linked to fluctuations in climate and environments, human demographics, and the size, extension, and type of social exchange networks. Such dynamics are particularly evident during the Last Glacial Maximum (LGM) timeframe, with a series of innovations emerging in the archaeological record, marking the transitions between the traditionally defined Gravettian, Proto-Solutrean, Solutrean, and Magdalenian technocomplexes. Stemming from a workshop organized in Erlangen in 2019 on “The Last Glacial Maximum in Europe - state of knowledge in Geosciences and Archaeology”, this paper presents, in the first part, an updated review on the paleoenvironments and human adaptations across four macro-regions (Northern, Inland, Mediterranean, and Western Atlantic Façade) in Iberia during the LGM; and, in a second part, a discussion on the pronounced inter-regional variability, unresolved research questions, and the most promising research topics for future studies.

Territoriality and the organization of technology during the Last Glacial Maximum in southwestern Europe

Climate changes that occurred during the Last Glacial Maximum (LGM) had significant consequences in human eco-dynamics across Europe. Among the most striking impacts are the demographic contraction of modern humans into southern refugia and the potential formation of a population bottleneck. In Iberia and southern France transformations also included the occurrence of significant technological changes, mostly marked by the emergence of a diverse set of bifacially-shaped stone projectiles. The rapid dissemination of bifacial technologies and the geographical circumscription of specific projectile morphologies within these regions have been regarded as evidence for: (1) the existence of a system of long-distance exchange and social alliance networks; (2) the organization of human groups into cultural facies with well-defined stylistic territorial boundaries. However, the degree and modes in which cultural transmission have occurred within these territories, and how it may have influenced other domains of the adaptive systems, remains largely unknown. Using southern Iberia as a case-study, this paper presents the first quantitative approach to the organization of lithic technology and its relationship to hunter-gatherers’ territorial organization during the LGM. Similarities and dissimilarities in the presence of morphological and metric data describing lithic technologies are used as a proxy to explore modes and degrees of cultural transmission. Statistical results show that similarities in technological options are dependent on the chronology and geographical distance between sites and corroborate previous arguments for the organization of LGM settlement in Southern Iberia into discrete eco-cultural facies.