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Testing Neanderthal behavioural hypotheses requires a spatial-temporal resolution to the level of a single human occupation episode. Yet, most of the behavioural data on Neanderthals has been obtained from coarsely dated, time-averaged contexts affected by the archaeological palimpsest effect and a diversity of postdepositional processes. This implies that time-resolved Neanderthal behaviour remains largely unknown. In this study, we performed archaeostratigraphic analysis on stratigraphic units ive, ivf, ivg, va, vb and vc from Abric del Pastor (Alcoi, Iberian peninsula). Further, we isolated the archaeological remains associated with the resulting archaeostratigraphic unit and applied raw material, technological, use-wear, archaeozoological and spatial analyses. Our results show a low-density accumulation of remains from flintknapping, flint tool-use and animal processing around a hearth. These data provide a time-resolved human dimension to previous high-resolution environmental and pyrotechnological data on the same hearth, representing the first comprehensive characterisation of a single Neanderthal occupation episode. Our integrated, multidisciplinary method also contributes to advance our understanding of archaeological record formation processes.

The relationship between hunter-gatherer group mobility and lithic raw material procurement strategies is central to the study of Neanderthal productive behaviours. In this framework, determination of flint procurement sources through lithological analysis is key to infer Neanderthal group mobility patterns. El Salt rockshelter (Alcoi, Alacant, eastern Iberia) features different nearby flint sources, including primary outcrops and secondary deposits containing flint. In this study, we sourced the stratigraphic unit viii archaeological flint assemblage based on identification of geogenic and postgenetic lithological traits. Our results indicate that flint procurement at El Salt during the stratigraphic unit viii Neanderthal occupations was mainly linked to Pleistocene secondary deposits along the upper and middle courses of Serpis river. The artefacts were made predominantly on alluvially reworked nodules of different flint types. Connecting these procurement areas with their corresponding knapping products reveals a direct relationship between flint-source distance and degree of technical intervention, and defines a hypothetically unidirectional series of rivershore itineraries of procurement. This work has been accomplished during the valid period of the research project titled Clima e interacciones humanas en el Mediterráneo central ibérico durante el MIS 4 (IBEMIS4), granted by the Spanish central government (PID2019-107113RB-I00). The first author (AM) is funded by Universitat d’Alacant through a university faculty formation grant (UAFPU2018-049). The second (SSR) and the fourth (LP) are funded by the Valencian autonomous government through a predoctoral research-staff contracting grant (ACIF/2021/407) and a postdoctoral research-staff contracting grant (APOSTD/2020/202), respectively.

High-altitude island environments, with their characteristic strong seasonal contrast and limited resources, are challenging contexts for human subsistence. However, although archaeological contexts in this kind of setting hold great potential to explore the diversity of human biological and cultural adaptations, such sites are rare. In this paper, we present the results of a microcontextual geoarchaeological study carried out at Roques de García Rockshelter, the highest altitude cave archaeological site in the Canary Islands (Spain). The site was inhabited by the aboriginal population of the island and has yielded a rich archaeological context derived from combustion activity. We carried out soil micromorphology to characterize site function and lipid biomarker analysis to investigate the natural and anthropogenic organic record. Our data indicate that the aboriginal groups that occupied the site kept goats with them (in the rockshelter) and probably used Juniperus turbinata (sabina) wood, a current distant fuel source. These results suggest that the aboriginal societies of Tenerife occupied the highlands regularly, taking their herds and firewood with them. Further research is necessary to explore the use and exploitation of fuel sources, the seasonality of these occupations and their differences with lowland sites.

El Salt (Middle Palaeolithic; Alcoi, Spain) is a key site for understanding the disappearance of Neanderthals in the eastern Iberian Peninsula, a process that is observed along its stratigraphic sequence. To improve our understanding of the palaeoclimatic context in which this process took place, we applied the UDA-ODA discrimination technique to the fossil herpetological assemblages from Stratigraphic Units (SU) Xb (52.3 ± 4.6 ka) and V (45.2 ± 3.4/44.7 ± 3.4 ka). This method is based in the application of an ecological criterion, the maximum altitude of each species on each Iberian range, to discern and remove those areas that do not meet their ecological requirements (UDA) from those that do (ODA), which are included in its distribution from Atlases from which the common distribution species is going to be extracted. Results indicate the existence of an alternation between “cold and wet” moments with “warm and dry” ones, all of them in a more humid context than nowadays. Climate was slightly warmer than nowadays in SU Xb, whereas was cooler in SU V. Regarding MAP, our results show less variation between SUs than it has been provided by previous studies. These results do not fully agree with those provided by small mammals from the same SUs, which indicate an increase of the temperatures whereas rainfall experienced the contrary. These differences could be related with the wider distribution of the Iberian herpetofauna, and some differences in the applied ecological criterion. Furthermore, herpetofaunal palaeoclimatic reconstruction shows that the abandonment of the site by Neanderthals seems to have occurred during an arid phase.

Investigations of organic lithic micro-residues have, over the last decade, shifted from entirely morphological observations using visible-light microscopy to compositional ones using scanning electron microscopy and Fourier-transform infrared microspectroscopy, providing a seemingly objective chemical basis for residue identifications. Contamination, though, remains a problem that can affect these results. Modern contaminants, accumulated during the post-excavation lives of artifacts, are pervasive, subtle, and even “invisible” (unlisted ingredients in common lab products). Ancient contamination is a second issue. The aim of residue analysis is to recognize residues related to use, but other types of residues can also accumulate on artifacts. Caves are subject to various taphonomic forces and organic inputs, and use-related residues can degrade into secondary compounds. This organic “background noise” must be taken into consideration. Here we show that residue contamination is more pervasive than is often appreciated, as revealed by our studies of Middle Palaeolithic artifacts from two sites: Lusakert Cave 1 in Armenia and Crvena Stijena in Montenegro. First, we explain how artifacts from Lusakert Cave 1, despite being handled following specialized protocols, were tainted by a modern-day contaminant from an unanticipated source: a release agent used inside the zip-top bags that are ubiquitous in the field and lab. Second, we document that, when non-artifact “controls” are studied alongside artifacts from Crvena Stijena, comparisons reveal that organic residues are adhered to both, indicating that they are prevalent throughout the sediments and not necessarily related to use. We provide suggestions for reducing contamination and increasing the reliability of residue studies. Ultimately, we propose that archaeologists working in the field of residue studies must start with the null hypothesis that miniscule organic residues reflect contamination, either ancient or modern, and systematically proceed to rule out all possible contaminants before interpreting them as evidence of an artifact’s use in the distant past.

This study presents a hydroclimatic reconstruction from Crvena Stijena (Montenegro, Balkan Peninsula), a rock shelter that has yielded evidence for Middle Paleolithic human occupation. The integration of lipid biomarkers, hydrogen (dD) isotopic compositions of n-alkanes, and organic elemental geochemistry in the 7-m deep vertical sedimentary sequence enables reconstruction of the main hydrological and environmental changes during the MIS 3 and their correlation with the presence at the site. We apply agglomerative hierarchical clustering and principal component analysis to the geochemical, molecular, and stable isotopic data to obtain a robust hydrological record. We find evidence of three aridity trends from the studied period, one of them correlated with the Heinrich Event 5, and humid and cold -temperate conditions in archaeology-rich layers. Our dataset also contributes to the knowledge of past hydrological variability in the Balkan Peninsula, a sensitive area to short-lived climatic shifts, and overall, in the Mediterranean region during the last glacial/interglacial cycle.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). BCS1758285 info:eu-repo/semantics/publishedVersion

El Salt is emerging as a reference site for the study of the extinction of Neanderthal populations in the Eastern Iberian Peninsula during MIS 3. The small vertebrate assemblage analysed in this work is framed within this general objective and comes from Stratigraphic Unit V, the most recent unit with human presence. Nearly 1300 small mammal remains have been studied in order to reconstruct the palaeoecological conditions of this debated period. A total of seven rodents (Microtus arvalis, Microtus duodecimcostatus, Microtus cabrerae, Sciurus vulgaris, Arvicola sapidus, Eliomys quercinus and Apodemus sylvaticus), three insectivores (Talpa occidentalis, Crocidura sp., Sorex sp.) and one lagomorph (Oryctolagus cf. cuniculus) were identified. Palaeocological analyse points to drier conditions in the upper part (Unit V) of the stratigraphic sequence, supporting the hypothesis that an aridification scenario may have played a role in the disappearance of the Neanderthal groups inhabiting this region of the Iberian Peninsula.

The locality of El Salt (Alcoi, Spain) is a key site for understanding the extirpation of Neanderthals in the eastern part of Iberia. In this paper, we analyse an assemblage of amphibians and reptiles from Stratigraphic Unit V (45.2 ± 3.4 ka to 44.7 ± 3.4 ka), which corresponds to one of the last regional records of Neanderthals, to improve knowledge of the palaeoecology and palaeoclimate of this event. The assemblage comprises three anurans (Pelodytes sp., Alytes obstetricans, and Epidalea calamita), two lizards (Lacertidae indet. and Chalcides bedriagai), and five snakes (Colubridae indet., Coronella sp., Coronella sp./Zamenis sp., Natrix maura, and Vipera latastei). Palaeoclimatic reconstruction, based on the Mutual Ecogeographic Range method, indicates that climate was cooler and slightly wetter climate than the present day climate of the Alcoi area. Applying the Habitat Weighting Method, we infer that the area surrounding El Salt was dominated by open dry regions, alternating with rocky areas with scarce scrubs and forest patches that would have developed under mesomediterranean conditions. These results are not entirely consistent with those obtained with other proxies (charcoal and small mammal assemblages) from the same site, which suggest slightly warmer and drier conditions. We hypothesise that these divergences may be partly related to the current wide distribution of reptiles and amphibians across Iberia. A key finding is that the extirpation of the Neanderthals in Iberia coincided with aridification. Fil: Marquina Blasco, Rafael. Universidad de Valencia; España. Museu Valencià D’història Natural; España Fil: Fagoaga, Ana. Universidad de Valencia; España. Museu Valencià D’història Natural; España Fil: Crespo Roures, Vicente Daniel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Museo Paleontológico de Alpuente; España Fil: Bailon, Salvador. Centre National de la Recherche Scientifique; Francia. Histoire naturelle de l’Homme prehistorique; Francia Fil: Mallol, Carolina. Universidad de La Laguna; España Fil: Hernández, Cristo M.. Universidad de La Laguna; España Fil: Galván, Bertila. Universidad de La Laguna; España Fil: Ruiz Sánchez, Francisco Javier. Universidad de Valencia; España. Museu Valencià D’història Natural; España. Universidad Estatal Península de Santa Elena; Ecuador

The El Salt site (Alcoi, Alicante, Spain) is one of the latest Neanderthal sites in the south-eastern Iberian Peninsula. The disappearance of this human group is controversial and needs detailed studies from different research areas. Taphonomy is essential to establish how representative is a fossil assemblage of the past living organisms that produced it and to interpret the formation process of the fossil site. In the case of El Salt, we have analyzed the micromammal assemblages of Units X and V, which contain fossils of Neanderthals and/or evidence of their activity. In contrast with previous identifications of the little owl (Athene noctua), our detailed taphonomic study shown here allows us to conclude that the main predator involved in the production of the micromammal assemblages was the European eagle owl (Bubo bubo). This is an opportunistic predator whose feeding preferences and behavior reflect the abundance of local micromammalian species, which can therefore provide a representation of past ecosystems near El Salt. The taphonomic information provided by this study also indicates the absence of transport and reworking processes, and reinforces previous paleoecological interpretations, suggesting an increase of aridity at the top of El Salt sequence that coincided with the local disappearance of Neanderthals., This investigation has been carried out thanks to the Spanish Government project HAR2015-68321-P: “Neandertales en la montaña alicantina. Un enfoque multianalítico” (2016–2019) MICINN-FEDER, and the project UV-INV_AE17-708551 (University of Valencia), Conselleria d’Educació, Investigació, Cultura i Esport from the Valencian Government and the University of La Laguna (Tenerife, Spain).

The small-vertebrates’ assemblage recovered comes from Units I to IV from El Salt site (Alcoi, Spain). The sample is composed by nearly 310 remains, and includes one toad (Epidalea calamita), two lizards (Lacertidae indet. and Chalcides cf. bedriagai), two snakes (Coronella cf. girondica and cf. Coronella sp.), two insectivores (Crocidura sp. and Sorex sp.), one lagomorph (Oryctolagus cuniculus) and seven rodent taxa (Arvicola sapidus, Microtus sp., M. arvalis, M. cabrerae, M. duodecimcostatus, Apodemus sylvaticus, and Eliomys quercinus). All the species described in the present work are consistent with a Late Pleistocene-Holocene chronology. The presence of M. cabrerae (absent in the Middle Pleistocene) and M. duodecimcostatus (absent in the Mediterranean until the Late Pleistocene) seem to confirm this age. The presence of Neolithic pottery and M. arvalis in the same deposit is inconsistent from a biochronically point of view since this species was extirpated from this region at the end of the Late Pleistocene. Several taphonomic alterations related to transport within the small mammal remains have been identified. Further taphonomical and geoarchaeological work is needed to clarify the provenience of the studied faunal assemblages, which, given the high energy, erosional morphology and lithology of the sedimentary deposit, could have been reworked in a more recent time period.

A comprehensive view of our evolutionary history cannot ignore the ancestral features of our gut microbiota. To provide some glimpse into the past, we searched for human gut microbiome components in ancient DNA from 14 archeological sediments spanning four stratigraphic units of El Salt Middle Paleolithic site (Spain), including layers of unit X, which has yielded well-preserved Neanderthal occupation deposits dating around 50 kya. According to our findings, bacterial genera belonging to families known to be part of the modern human gut microbiome are abundantly represented only across unit X samples, showing that well-known beneficial gut commensals, such as Blautia, Dorea, Roseburia, Ruminococcus, Faecalibacterium and Bifidobacterium already populated the intestinal microbiome of Homo since as far back as the last common ancestor between humans and Neanderthals., Simone Rampelli, Silvia Turroni and colleagues report ancient bacterial profiles of fecal sediments from four stratigraphic units of El Salt Middle Paleolithic site in Spain. The results of this study suggest a core human gut microbiome that could have been shared by Neanderthals and modern humans, and would pre-date the split between these two lineages.

An archaeomagnetic, rock magnetic and magnetic fabric study has been carried out on seven anthropogenic ash horizons in theMiddle Palaeolithic sedimentary level XXIV at the rock shelter of Crvena Stijena (‘Red Rock’), Montenegro. The study has multiple goals, including the identification of iron bearingminerals formed during combustion, assessment of the suitability of these combustion features for recording the Earth´s magnetic field direction, revelation of the magnetic fabric and its significance in the characterization of cave (rock shelter) burnt facies, and identification of post-burning alteration processes. Magnetite has been identified as themain ferromagnetic component of the ash. The ash layers exhibit a high thermomagnetic reversibility in contrast to the irreversible behaviour of their subjacent burnt black layers which is related to the different temperatures attained. Seven mean archaeomagnetic directions were obtained with acceptable statistical values indicating that these features recorded the field direction at the time of burning. However, some of them are out of the expected range of secular variation for mid-latitude regions suggesting post-burning alterations. The magnetic fabric of the ash was characterized by anisotropy of low field magnetic susceptibility measurements. Statistical analysis (box and whisker plot) of the basic anisotropy parameters, such as foliation, lineation, degree of anisotropy and the shape parameter, along with the alignment of the principal susceptibilities on stereoplots, revealed variation among the ash units. The diverse, oblate to prolate, lineated or strongly foliated, quasi-horizontally and vertically oriented fabrics of the units may indicate different slope processes, such as orientation by gravity, solifluction, run-off water, quasi-vertical migration of groundwater and post-burning/post-depositional alteration of the fabric by rockfall impact. In sum, the magnetic characterization of the ash layers has shown the occurrence of different post-burning alteration processes previously not identified at the site. Alteration processes in prehistoric combustion features are often identified from macroscopic observations but our study demonstrates that multiple processes can affect them and are usually unnoted because they take place on a microscopic scale. Their identification is critical for a correct chronological and cultural interpretation of a site (e.g. collection of samples for dating, stratigraphic displacement of remains), especially if significant alterations are involved. Magnetic methods are therefore a powerful but underutilized tool in palaeolithic research for the identification and evaluation of taphonomic processes affecting prehistoric fires., BU235P18 (Junta de Castilla y León, Spain) and the European Regional Development Fund(ERDF) and the CGL2016-77560- C2, PID2019-108753GB-C21 and PID2019-105796GB-I00 of the Agencia Estatal de Investigación (AEI/10.13039/501100011033). AHL gives thanks to Junta de Castilla y León (Spain) and European Social Fund for the financial support during her predoctoral period. Micromorphological investigations by CM are funded by ERC Consolidator Grant project ERC-2014-CoG- 648871-PALEOCHAR.

The nature and timing of the shift from the Late Middle Paleolithic (LMP) to the Early Upper Paleolithic (EUP) varied geographically, temporally, and substantively across the Near East and Eurasia; however, the result of this process was the archaeological disappearance of Middle Paleolithic technologies across the length and breadth of their geographic distribution. Ortvale Klde rockshelter (Republic of Georgia) contains the most detailed LMP-EUP archaeological sequence in the Caucasus, an environmentally and topographically diverse region situated between southwest Asia and Europe. Tephrochronological investigations at the site reveal volcanic ash (tephra) from various volcanic sources and provide a tephrostratigraphy for the site that will facilitate future correlations in the region. We correlate one of the cryptotephra layers to the large, caldera-forming Nemrut Formation eruption (30,000 years ago) from Nemrut volcano in Turkey. We integrate this tephrochronological constraint with new radiocarbon dates and published ages in an OxCal Bayesian age model to produce a revised chronology for the site. This model increases the ages for the end of the LMP (∼47.5–44.2 ka cal BP) and appearance of the EUP (∼46.7–43.6 ka cal BP) at Ortvale Klde, which are earlier than those currently reported for other sites in the Caucasus but similar to estimates for specific sites in southwest Asia and eastern Europe. These data, coupled with archaeological, stratigraphic, and taphonomic observations, suggest that at Ortvale Klde, (1) the appearance of EUP technologies of bone and stone has no technological roots in the preceding LMP, (2) a LMP population vacuum likely preceded the appearance of these EUP technologies, and (3) the systematic combination of tephra correlations and absolute dating chronologies promises to substantially improve our inter-regional understanding of this critical time interval of human evolution and the potential interconnectedness of hominins at different sites.

The identification and characterization of hearths is crucial for reconstructing the history of fire use and pyrotechnology. In addition to ashes and charcoals, an active fire will also produce alterations of the underlying substrate to varying degrees. To date, however, few studies have addressed how the characteristics of burned substrates relate to pyrotechnology. Here, we systematize the use of colour to identify burnt sediments by performing quantitative colour measurements in the CIELab system of experimentally heated soils and sediments. The experimental design included different temperatures, different heating durations and substrates with varied chemical and mineralogical compositions, including naturally red soils and sediments with different degrees of pedogenesis. The measured colours were analysed by multivariate statistics for diagnosing whether sediments have been heated or not, and to which temperature. We achieved an accurate identification of heated versus unheated samples independently of their composition. The determination of the temperature of heating required prior knowledge of basic mineralogy and chemical properties in the targeted sediments (silicate or carbonate material, total and secondary Fe, Ca contents and the amount and kind of organic matter). The algorithm developed can be applied to recognize burned layers and estimate burning temperatures in archaeological contexts. info:eu-repo/semantics/publishedVersion

This paper reports on a series of heating experiments that focus on n-alkanes extracted from leaf, bark, and xylem tissues of the Celtis australis plant. These lipid biomarkers were analysed for their compound-specific hydrogen isotopic composition (δ2Hwax) under limited oxygen conditions at 150, 250, 350, and 450 °C. Our results reveal isotopic variations in wax lipids of different plant organs during short-term low-temperature combustion. We conclude that, in the absence of a detailed characterisation of the depositional environment in advance of sampling, δ2Hwax values in archaeological or otherwise highly anthropogenic environments should be interpreted cautiously. In addition, we observed that variation is δ2Hwax of leaves is minimal at temperatures ≤ 350 °C, highlighting the potential for δ2Hwax in thermally altered combustion substrates to yield palaeoclimate information, which could allow researchers to investigate links between archaeological and climatic records at a high spatial and temporal resolution.

Burned or charred organic matter in anthropogenic combustion features may provide important clues about past human activities related to fire. To interpret archaeological hearths, a correct identification of the organic source material is key. In the present work, Raman spectroscopy is applied to characterise the structural properties of char produced in laboratory heating- and open-fire experiments. This reference data set is compared to analyses of three different archaeological sites with Middle Palaeolithic combustion contexts. The results show that it is possible to determine whether a charred fragment is the product of burning animal-derived matter (e.g. meat) or plant-derived matter (e.g. wood) by plotting a few Raman spectral parameters (i.e. position of G and D bands, and intensity ratios HD/HG and HV/HG) against one another. The most effective parameters for discriminating animal- from plant-derived matter are the position of the G band and the HV/HG intensity ratio. This method can be applied on raw sample material and on uncovered micromorphological thin sections. The latter greatly compliments micromorphology by providing information about char fragments without any clear morphological characteristics. This study is the first of its kind and may provide archaeologists with a robust new method to distinguish animal- from plant-derived char in thin sections.

El Salt is an important reference site for understanding the extinction of Neanderthal populations in the eastern Iberian Peninsula during MIS 3. In this paper, we describe the small mammal assemblage from Stratigraphic Unit V, the youngest unit with evidence of human presence, based on nearly 1300 specimens. A total of seven rodents (Microtus arvalis, Microtus duodecimcostatus, Microtus cabrerae, Sciurus vulgaris, Arvicola sapidus, Eliomys quercinus and Apodemus sylvaticus), three insectivores (Talpa occidentalis, Crocidura sp., Sorex sp.) and one lagomorph (Oryctolagus cf. cuniculus) were identified. Palaeocological analyses point to drier conditions in this part of the stratigraphic sequence, supporting the hypothesis that an aridification scenario may have played a role in the extinction of the Neanderthal groups inhabiting this region of the Iberian Peninsula., Research at El Salt is funded by the Spanish Government project HAR2015-68321-P (MINECO FEDER/UE), UV-INV_AE17-708551 (University of Valencia) and Conselleria d'Educació, Investigació, Cultura i Esports from the Valencian government. This investigation was also carried out thanks to the Prometeo Project of the Secretariat for Higher Education, Science, Technology and Innovation from Ecuador and the University of La Laguna (Tenerife, Spain).

Within the framework of archaeological palimpsest dissection, stratigraphic association of lithic remains with hearths and other archaeological materials in undisturbed Neanderthal contexts allows us to seek patterns in lithic and faunal assemblage composition, assess the degree of time averaging within assemblages and investigate the spatial distribution of archaeological remains. So far, the European Neanderthal record shows variability in such spatial parameters, not only among different geographic regions but also across time. This approach has been employed to draw conclusions about the main features of Neanderthal occupations from in situ archaeological contexts within individual site sequences. As contribution to this topic, we present new results from our ongoing archaeostratigraphic investigation of stratigraphic unit xa from El Salt (Alcoi, Alacant, eastern Iberia). Our previous study, based on stratigraphic analysis of the lithic record consisting of raw material units, yielded several micropalimpsests within unit xa. Here, we carry out further technological and spatial analysis of the micropalimpsest units. The results obtained from it suggest that we may be able, in specific cases, to recognise indicators of diachrony within the context of these archaeostratigraphic units. This confirms the existence of a micropalimpsest, and suggests that we have the chance to find analytical frames that are even closer to the human temporal scale than the AU. This should be the target of future interdisciplinary behavioural study of El Salt unit xa. This work illustrates the potential of a spatial and archaeostratigraphic approach to stone tool technology and brings to light the importance of archaeological palimpsest dissection as a first step for behavioural analysis in Palaeolithic research. Archaeological excavations at El Salt rockshelter are funded by the Spanish central government through the project called Neandertales en la montaña alicantina: un enfoque multianalítico (MEC-FEDER HAR2015-68321-P), and by the Valencian autonomous government through public research funding (DOGV P-0300900-H). One of the authors (AM) is also funded by Universitat d’Alacant through a university faculty formation grant (UAFPU 2018-049).

Tropical dry islands are currently facing major challenges derived from anthropogenic and climatic pressures. However, their trajectories of environmental change, which could provide relevant information applicable to biodiversity conservation, remain understudied. This is mainly due to poor micro-fossil preservation and irregular sediment deposition. Multi-proxy palaeoecological analyses spanning decades to 1000s of years can add perspective as to how vegetation, fungal communities, and the fauna responded to previous natural and anthropogenic disturbances. In Sao Nicolau, Cabo Verde, we used palaeoecological methods to analyse a highland soil profile (1000 m asl) dated to 5900 cal yr BP. We analysed how vegetation (abundances in pollen of native and introduced species, and leaf wax n-alkanes), ferns and fungal communities (abundance of non-pollen palynomorphs) varied over time in relation to fire (charcoal concentration) and erosion regimes (grain sizes and elemental composition). Between 5000 and 400 cal yr BP the highlands held native woody taxa such as Euphorbia tuckeyana, Dracaena draco subsp. caboverdeana, and Ficus, taxa that can be used for future reforestation programmes. From 400 cal yr BP to the present day, replacement of native taxa by introduced and cultivated taxa (Pinus, Eucalyptus, Asystasia, Opuntia) has occurred. Vegetation burning and grazing caused loss of vegetation and erosion, acting as conjoined drivers of scrubland degradation. This dataset helps to set historically contextualised restoration goals such as the re-introduction of native species, monitoring of recently introduced species and control of free grazing. This can serve as a model system for the conservation of tropical dry islands' biodiversity.

Hearths present sedimentary features, artifacts, and direct evidence for maintained and controlled fire in the past. The use of hearths reflects regular access to fire and its diverse benefits. Among these benefits are cooked food, protection from the cold and from predators, and fire’s transformative power regarding raw materials. Hearths may have also served as focal points of activity at Paleolithic campsites and triggered changes in social structures. As sedimentary features, combustion structures function as behavioral as well as paleoenvironmental archives. The papers in this special issue focus on the former aspect, how combustion feature can serve as transmitters of behavior, and with what tools we can explore them. We here briefly present an overview on the range of topics explored in these papers, which include ethnoarchaeological research on fire use among recent hunter-gatherer groups, spatial analysis of burnt lithics, actualistic experiments regarding fire function and fire use in tool production.

Analyses devoted to palimpsest dissection and archaeological assemblage formation are currently topics of growing interest in Palaeolithic research. For many researchers, it is becoming increasingly clear that the temporal dimension of archaeo-sedimentary deposits should not be overlooked, because approaches based on the analysis of diachronically deposited assemblages impede accurate behavioural interpretations. In this work, we present the results of the zooarchaeological and taphonomic analyses of faunal remains from several high-resolution analytical contexts defined by archaeostratigraphic techniques in Stratigraphic Unit Xa from the Middle Palaeolithic site of El Salt. Our main goal is to identify behavioural tendencies related to the treatment of animal resources at a temporal scale of analysis as close as possible to ‘ethnographic time’. The behavioural, spatial and temporal information resulting from this study and from previous works based on the lithic record is discussed in order to investigate the settlement dynamics of Neanderthal groups in the highlands of Alicante (southeastern Iberian Peninsula) during the MIS 3.

The Carbon Preference Index (CPI) is a molecular ratio often used to assign the biological source and maturity of organic matter. This parameter is frequently employed in paleoenvironmental studies and archaeological applications. In this paper, we have evaluated the different results for this index using peak areas or concentrations from calibration curves. For this purpose, plant reference samples (Celtis Australis L.) and sediments from two archaeological sites were analysed. The results show that the values obtained depend on the method employed and, thus, interpretations may differ significantly. Consequently, the method used must be clearly stated in each particular application and results can only be compared when using the same protocol.

Leaf waxes have been assumed to be the dominant source of wax delivered to sediment. However, wooden branches and twigs have not been widely considered in this context and could be a potential source of wax lipids in fire places or combustion structures. Black sedimentary layers are the main material of open-air archaeological combustion structures and represent either carbonized fuel (wood) or the charred ground beneath the fire (mainly leaves) and it is difficult to discern between the two sources. To identify different plant parts as components of combustion residues, fresh and charred leaves, branches and twigs (bark and xylem) of the Celtis australis tree were analyzed for aliphatic and aromatic hydrocarbons and fatty acid concentrations, as well as the carbon isotopic composition of n-alkanes (δ13Calkane). Charred biomass was produced under limited oxygen conditions at 150, 250 (3 and 5 h), 350 and 450 °C for 1 h. The n-alkyl profiles in different parts of C. australis are sufficiently distinct to allow their identification as components of combustion structures under low combustion temperature conditions. Average chain lengths and carbon preference index ratios decrease with increasing temperature and vary among plant parts. The δ13Calkane values remained slightly unaltered up to 350 °C and changed by 3–4‰ at 450 °C. Our results provide new information on the molecular and isotopic changes that occur upon burning different plant parts, which in turn show potential for good preservation of organic matter in archaeological black layers and for positive identification of burned leaf and wood residues in them.

Although the occurrence of burned bones in the archeological record has been widely investigated, very few studies have focused on the distinction of temporality in burned bones assemblages, which would be useful in helping to identify human activity areas, as well as distinguishing combustion residues from those resulting from other activities. In this work, we present the results of an experiment designed to characterize direct/indirect thermal alteration of rabbit bones, based on macroscopic and microscopic surface features. These results are then compared with an archeological burned bone assemblage associated with various Middle Paleolithic combustion structures from El Salt Stratigraphic Unit X (Alicante, Spain). In the experimental assemblage, we observed that rabbit bones tossed into a fire were strongly altered, while bones thrown on the cooled ashes and lying on the surface beneath the fire or slightly buried, were not. We observed a strong thermal surface alteration of fresh bone (color changes, high degrees of fragmentation, cracks and structural changes on the cortical surface), while dry bone showed only color changes. Taking this data into account when analyzing the archeological assemblage, we observed surface features corresponding to thermally altered fresh bone and others more like thermally altered dry bone. Crucially, the archaeological specimens are associated with black layers of combustion structures and exhibit signs of trampling. The results suggest that fresh bones were trampled into human occupation surfaces and were subsequently unintentionally or indirectly burned due to their position beneath hearths, along with other dry bones present there. Our study shows that investigating ways to distinguish temporality in burned bones may be a good tool for isolating different depositional events and thus contributing to archeological palimpsest dissection.

This paper presents a multiproxy palaeoenvironmental study from Abric del Pastor (Alcoy, Spain), a rock shelter which has yielded evidence for Middle Palaeolithic human occupation. The sedimentary sequence has been analysed for lipid biomarker n-alkane abundances (ACL, CPI), compound specific leaf wax δH and δC, and bulk organic geochemistry (TOC, %N, %S), providing a record of past climate and local vegetation dynamics. Site formation processes have been reconstructed through the application of soil micromorphology. Analyses of anthracological, microvertebrate and macrofaunal assemblages from selected subunits are also presented here. Our data indicates that a variable climate marked by predominantly cold conditions persisted through most of the sequence and that Neanderthal occupations in stratigraphic unit IVd, assigned to MIS 4 or late MIS 5, occurred in a landscape setting characterised by a mosaic of biotopes. The presence of key resources inside the ravine where the site is located suggests that the occupation of the rock shelter may have been strategically motivated by a subsistence and mobility strategy which focused on zones of localised ecological resilience, such as intra-mountainous valleys or ravines, during periods of global or regional environmental downturn., This research was supported by the ERC Consolidator Grant project PALEOCHAR – 648871. Excavations at Abric del Pastor are funded by Spanish Ministry of Science, Innovation and Universities Project HAR2015-68321-P and the Government of Valencia Cultural Heritage Department.

There is a relatively low amount of Middle Paleolithic sites in Europe dating to MIS 4. Of the few that exist, several of them lack evidence for anthropogenic fire, raising the question of how this period of global cooling may have affected the Neanderthal population. The Iberian Peninsula is a key area to explore this issue, as it has been considered as a glacial refugium during critical periods of the Neanderthal timeline and might therefore yield archaeological contexts in which we can explore possible changes in the behaviour and settlement patterns of Neanderthal groups during MIS 4. Here we report recent data from Abric del Pastor, a small rock shelter in Alcoy (Alicante, Spain) with a stratified deposit containing Middle Palaeolithic remains. We present absolute dates that frame the sequence within MIS 4 and multi-proxy geoarchaeological evidence of in situ anthropogenic fire, including microscopic evidence of in situ combustion residues and thermally altered sediment. We also present archaeostratigraphic evidence of recurrent, functionally diverse, brief human occupation of the rock shelter. Our results suggest that Neanderthals occupied the Central Mediterranean coast of the Iberian Peninsula during MIS 4, that these Neanderthals were not undergoing climatic stress and they were habitual fire users., This research was funded by a Leakey Foundation General Grant, Spanish Ministry of Science, Innovation and Universities Projects HAR2008-06117/HIST and HAR2015-68321-P, Junta de Castilla y León-FEDER Project BU235P18, the LabEx Sciences Archéologiques de Bordeaux (LaScArBx ANR-10-LABX-52) and ERC Consolidator Grant ERC-CoG-2014. Archaeological excavations at Abric del Pastor are supported by the Archaeological Museum of Alcoy and the Government of Valencia Cultural Heritage Department.

Molecular and isotopic approaches offer the chance to identify combustion residues and substrate components of archaeological combustion features to infer past fire-related activities. Analysis of fatty acid methyl esters by gas chromatography-combustion-isotope ratio mass spectrometry have been successfully used to distinguish among different animal fat groups. However, plant oils from different tissues have not been widely investigated even though organic residues from leaf, root, and wood tissues are preserved in sediments from archaeological combustion structures. Our analyses of plant residues from controlled laboratory heating sequences and experimental hearths involving wood and animal residues, provide references to discern anatomical parts of fresh and charred plants and to differentiate contributions of terrestrial plants and animal sources in open air hearths. This information is compared with charred organic residues from combustion structures from three Middle Palaeolithic sites: El Salt (Spain), Abric del Pastor (Spain) and Crvena Stijena (Montenegro). The occurrence of n-alkyl nitriles in our samples corroborates their potential as combustion temperature biomarkers and the δ13C16:0 and δ13C18:0 values allow us differentiate between charred and fresh plant anatomical parts and between fresh plant oils and animal fats.

Protocol for the manufacture of micromorphological thin sections performed at AMBI Lab, Universidad de La Laguna, Tenerife, Spain.

Molecular and isotopic analysis of sediments from archaeological combustion features is a relatively new area of study. Applications can inform us about ancient pyro-technologies and patterns of animal exploitation in a wide range of human contexts, but may be particularly informative with regard to ancient hunter-gatherers. Our analyses of sediments from experimental bone and wood fires, and from controlled laboratory heating sequences, provide fine-grained data on the formation and location of biomarkers from pyrolyzed animal fats in hearths. Integrating microstratigraphic, molecular, and isotopic data can improve recognition of bone fires in archaeological contexts, perhaps even where bone preservation is poor. Experimental bone fires produced an upper layer of calcined bone above a thin layer of tarry black amorphous material coating mineral sediments. Mineral sediments beneath the black layer showed little alteration but high lipid content. Sampling for molecular and isotopic analysis should target the black layer as the bulk of pyrolyzed biomarkers are located here and stable isotope values are less affected than in the overlying layer of ash or calcined bone. The combined presence of certain symmetric and slightly asymmetric saturated long-chain ketones (14-nonacosanone, 16-hentriacontanone 16-tritriacontanone, and 18-pentatriacontanone), especially together with heptadecane (C17n-alkane), are molecular indicators of the thermal degradation of terrestrial animal fat. Formation and relative dominance of these molecules in hearth sediments relates to the initial prevalence of specific precursor fatty acids and can provide broad separations between sources. We suggest that separations could be further supported and expanded by combining stable isotope analysis of the same compounds.

El Salt is an important reference site for understanding the extinction of Neanderthal populations in the eastern Iberian Peninsula during MIS 3. In this paper, we describe the small mammal assemblage from Stratigraphic Unit V, the youngest unit with evidence of human presence, based on nearly 1300 specimens. A total of seven rodents (Microtus arvalis, Microtus duodecimcostatus, Microtus cabrerae, Sciurus vulgaris, Arvicola sapidus, Eliomys quercinus and Apodemus sylvaticus), three insectivores (Talpa occidentalis, Crocidura sp., Sorex sp.) and one lagomorph (Oryctolagus cf. cuniculus) were identified. Palaeocological analyses point to drier conditions in this part of the stratigraphic sequence, supporting the hypothesis that an aridification scenario may have played a role in the extinction of the Neanderthal groups inhabiting this region of the Iberian Peninsula.

We present a new method based on the QuEChERS protocol (Quick, Easy, Cheap, Effective, Rugged, and Safe) for the determination of 29 n-alkanes (C12-C40) and two isoprenoid acyclic hydrocarbons (pristane and phytane) in sediments using gas chromatography-mass spectrometry for their separation and determination. Different factors affecting the extraction efficiency of these lipid biomarkers (such as type of extraction solvent, water addition proportion and timing, agitation mode, and type and amount of clean-up sorbent) were optimized by means of a step-by-step approach. The methodology was validated in terms of matrix-matched calibration, detection and quantification limits, and recovery using 5-α-androstane as internal standard. Calibration curve determination coefficients were higher than 0.9902 while relative recovery values varied in the range 60–117% for alkanes C20-C40, C14, C16, and C18 and 34–69% for C12, C13, C15, C17, C19, pristane, and phytane, with relative standard deviation values below 20%. The method's quantification limits ranged between 2.2 and 37.9 ng/g. Finally, five sediment samples from the Neanderthal site of El Salt (Alicante, Spain) were analyzed using the new method, yielding alkanes C22 to C34 with odd to even predominance and C16 to C33. This paper represents the first application of QuEChERS for the extraction of alkanes and the analysis of archaeological or geochemical samples

International audience; Processing and combustion of animal products including bone, fat, and oil for food and fuel can provide a crucial source of calories, heat, and light in cold, fuel-poor environments. Previous studies have shown that remnant lipids from the combustion and processing of animal products preserve exceptionally well in many Arctic sites, and various terrestrial and aquatic lipid sources can be identified through combined molecular and isotopic analyses. Similar analyses could be applied to fire-related sediments from some Middle and Upper Paleolithic sites. However, there are added challenges to the detection and identification of lipid sources in very old deposits and those located in warmer environmental settings. Lipid concentrations in Middle and Upper Paleolithic combustion structures are expected to be much lower than those encountered in more recent Arctic sites. Furthermore, difficulties distinguishing certain more recent lipids from ancient lipids could introduce interpretive errors. Given these concerns, biomarker selection in this study has focused on compounds with greater long-term preservation potential than those typically relied upon in arctic settings. Our research is also focused on specific molecules that can be linked to combustion events. This talk will present data on the molecular and isotopic analysis of black layers from experimental fires as well as data from laboratory heating experiments. Experimental fires were constructed with various combinations of ruminant long-bones, seal oil, and wood. Laboratory heating experiments sought to produce the same biomolecules under more controlled conditions using a variety of animal tissues, temperature programs, and artificial sediments. Analysis of black layers from experimental fires and laboratory heating experiments have identified a suite of biomarkers formed through pyrolysis of animal fats, which are otherwise rare in the environment. Applications to Middle and Paleolithic fire-related sediments may provide a unique line of evidence on resource processing and technological behaviors related to heating, lighting, and food preparation.

International audience; Remnant lipids from the combustion and heat-related processing of animal products preserve exceptionally well in many Arctic sites. Various terrestrial and aquatic lipid sources can be identified through combined molecular and isotopic analyses, but studies are still in an early phase. Here, we present results from recent field and laboratory experiments that provide clarification on pyrogenic biomarker formation in combustion related sediments. Our analyses of sedimentary layers from experimental fires, laboratory heating experiments, and archaeological hearths have identified a range of biomarkers formed through pyrolysis of animal fats, which are otherwise rare in the environment.

International audience; Ethnoarchaeology of fire and combustion residues: Current approaches