Marine Isotope Stage 5 (MIS 5) is well represented in palynological studies of North Atlantic marine cores but in only a handful of archeological sequences from the adjacent Iberian landmass. In this ...paper, we undertake a multi-proxy analysis of small mammal assemblages (insectivores, bats, and rodents) from a 6 m-thick succession, dated to MIS 5a-5b (Layers 7–22), situated in the southeastern edge of the Central Limestone massif of Estremadura at Gruta da Oliveira, near Torres Novas, Portugal. Application of quantitative (Habitat Weighting, Simpson's Diversity Index) and qualitative (Mutual Ecogeographic Range, Bioclimatic Model, Quantified Ecology) methods suggest that open woodland habitats were dominant through the time of accumulation with reconstructed mean annual temperatures (MAT) tracking the 18O curve from the NorthGRIP ice core, from the end of MIS 5c to the beginning of MIS 4. Our findings are consistent with the general trends derived from other Gruta da Oliveira proxies (wood charcoal, coprolite pollen, large mammal associations), limited evidence from other MIS 5 terrestrial sites in Iberia, and offshore marine palynological records.
•Combined quantitative and qualitative methods to reconstruct MIS 5 at Gruta da Oliveira.•Small-mammal assemblage used as a proxy to apply these methods.•A landscape dominated by open woodlands habitats has been identified.•Findings are consistent with the trends reported from other Gruta da Oliveira proxies.•Results accord with data from marine core pollen and other MIS 5 Iberian sites.
Archaeological remains have highlighted the fact that the interglacial Marine Isotope Stage (MIS) 11 was a threshold from the perspective of hominin evolution in Europe. After the MIS 12 glaciation, ...considered one of the major climate-driven crises experienced by hominins, the archaeological records show an increasing number of occupations, evidence of new subsistence behaviors, and significant technical innovations. Here, we used statistical and geographic techniques to analyze the amphibian- and reptile-based paleoclimate and habitat reconstructions generated from a large data set of the Iberian Peninsula to (1) investigate if temperature, precipitation, and/or forest cover may have impacted the hominin occupation of the territory during the Early and Middle Pleistocene, (2) propose an ‘Iberian’ ecological model before and after the MIS 12/11 transition, and (3) evaluate, based on this model, the potential hominin occupation at a European scale. The results indicate the existence of climatic constraints on human settlement related to rainfall and environmental humidity. The Early Pleistocene and the first half of the Middle Pleistocene are dominated by the occupation of relatively humid wooded areas, whereas during the second part of the Middle Pleistocene, a broadening of the earlier ecological niche is clearly observed toward the occupation of more open arid areas. Based on the estimated occupational niche for hominins, a maximum potential distribution for early hominins is proposed in Europe before and after 426 ka. Results also indicate that parts of the Iberian Peninsula may not have been suitable for early hominin occupation. Our ecological model is consistent with the pattern of hominin occupation observed in northern and central Europe, where the earliest evidence reflects only pioneering populations merely extending their ranges in response to the expansion of their preferred habitats, as compared with a more sustained occupation by 400 ka.
•Human settlement in southern Europe is related to rainfall and environmental humidity.•Before MIS 11, hominins occupied relatively humid wooded areas.•After MIS 11, hominins had the potential to be in more open arid environments.•The potential distribution for early hominins after 426 ka is much larger in Europe.•Mediterranean Europe was not always a suitable place for early hominins.
The environmental and climatic evolution of the late Middle Pleistocene to Late Pleistocene of the Garraf Massif (northeastern Iberia) is determined for Marine Isotope Stage 7 (MIS 7) to MIS 3 on the ...basis of a study of the small-vertebrate (amphibian, squamate reptile, insectivore, bat and rodent) assemblages. This paper provides a synthesis of three previously published and one partially published sets of environmental and climatic data from the Middle to Upper Paleolithic sites of Cova del Rinoceront, Cova del Gegant, Cova del Coll Verdaguer and Terrasses de la Riera dels Canyars, all of which are located in the Garraf Massif mountain range. Using the habitat weighting and mutual ecogeographic range methods to reconstruct the environmental and climatic parameters, the results show great variability in the landscape and climate of the area. However, although the human occupation is not intense in the analyzed sites, the various layers of the sites in which the human presence is relatively more intense coincide with landscapes dominated by woodland formations in mild climatic conditions. A comparison of our results with those from other sites with studies of small vertebrates in Greece, Italy, southern France, and the Iberian Peninsula reveals the same pattern, showing that the hominins that inhabited the western Mediterranean region in the late Middle Pleistocene and Late Pleistocene were closely related to forested areas.
•Synthesis of climatic and environment data for Middle-late to late Pleistocene.•Mutual Ecogeographic Range and Habitat weighting used to reconstruct its conditions.•Methods applied in the same way for herpetofauna and small mammal's assemblages.•Results shows a great variability of the landscape and climate of the studied area.
Understanding past climate and the mechanisms of climate change remain major challenges in scientific research. The Mutual Ecogeographic Range (MER) method for climatic reconstruction uses the ...current geographical distribution of fossil assemblages to infer palaeoclimatic conditions. Current species distributions used in the MER method are usually obtained from biogeographic atlases that record the absence/presence of species in a 10 × 10 km grid. A 10 × 10 km area is quite broad and the method only records presence/absence, without considering the real area occupied by any given species. Thus, the method overlooks the fact that environmental heterogeneity is strongly related to topography, and climatic conditions may change abruptly over a few kilometres. To improve the accuracy of small vertebrate palaeoclimatic reconstructions derived from the MER method, we developed the UDA-ODA discrimination methodology, which is applied to stratigraphic units Xb and Upper Unit V from El Salt (Alcoi, Spain). We identified the Occupied Distribution Area (ODA), which denotes realistic occupied areas where the species may be present and the UDA (Uncertain Distribution Area) where the species may be absent. We achieved this by combining the species’ distribution recorded in the atlases and the species environmental requirements described in the literature. Climate values resulting from the MER method and our UDA-ODA discrimination methodology showed significant differences. Extrapolating values from areas that are more similar to the areas occupied by the different species today yielded more representative climatic parameters for the assemblage tested, resulting in a more accurate palaeoclimatic reconstruction. Moreover, the discrimination analysis proposed here allows us to work with species whose distribution is currently disturbed, which was not possible using the MER method.
•UDA-ODA discrimination methodology provides more accurate climatic reconstructions.•GIS allow us to obtain reproducible results of the reconstruction process.•The methodology enables the inclusion of the species with perturbed distribution.
One of the major challenges in scientific research is to understand past climate and the mechanisms of climate change. Small vertebrates, and especially rodents, are very sensitive to shifts in ...climate and habitat, and their variations over time in terms of taxa and abundance can be successfully used to reconstruct past environments. The vast array of approaches to palaeoclimatic reconstruction reflects the great effort that has gone into this line of investigation. Recently, the UDA-ODA discrimination technique has been postulated as a more reliable ecologically-based methodology compared to the classical MER method.
To provide biogeographical information to be analysed by the UDA-ODA discrimination technique, the distributions of four species (Sorex minutus, Chionomys nivalis, Talpa europaea and Crocidura russula) documented in levels O, N, E and D of the Abric Romaní site were processed. The results reveal a statistical difference between the climatic values for the occupied distribution areas (ODA) and those for the uncertain distribution areas (UDA). This technique was then applied to small-mammal assemblages from the above-mentioned levels of Abric Romaní, to test whether the use of the ODAs of the species improves the precision of the climatic reconstruction compared to the atlas distributions of the species used in MER procedures. Our results suggest an improvement in the discrimination analysis over the previous MER reconstructions when wider distributions for an assemblage are obtained. The coldest values obtained for level O of Abric Romaní seem to reinforce the pollen interpretation of the level as coetaneous with a cold period. For the whole MIS 3 climatic scenario for Neanderthals, a colder and wetter climate is derived from the small-mammal analysis. However, as different methods and analyses have inherent limitations, a standardization of the methods applied to the different levels and sites should be carried out in order to provide comparable results.
•Species' ODAs from Abric Romaní got more accurate climatic results only in level D.•Wider mutual distributions imply high probability of precision with ODAs.•Consistency between methods is observed in the climatic tendency along the sequence.•A cold and wet scenario is deduced from the different proxies and methods applied.
Dmanisi (Georgia) is one of the oldest Early Paleolithic sites discovered out of Africa. In addition, it is the best site to understand the first Homo deme out of Africa and the first hominin ...occupation of Central to Western Eurasia. It has produced more than 40 hominin remains, including several very informative skulls, found in direct association with faunal remains and numerous lithic artifacts. To date, fossil amphibians and reptiles are one of the few proxies that have been used to propose quantitative climate reconstructions for the time where the hominins were living at Dmanisi. The aim of the present study is to review and amplify the previous paleoclimatic interpretation given by Blain et al. (2014), with an enhanced methodology using geographic information system and based on uncertain distribution area-occupied distribution area discrimination technique. This procedure permits to approach to a more precise common species distribution area and then using the WorldClim v. 2.1 climate database to propose for the first time monthly reconstructions for temperature and rainfall, in addition to annual parameters. The same technique is used to infer dominant ecoregions through the study area and potential tree coverage. Dmanisi climate is newly reconstructed as warm and semi-arid, similar to the present-day Mediterranean climate. New estimates however suggest warmer temperatures than previously reconstructed, together with a slightly higher but much more irregular amount of rainfall. The aridity indexes suggest a six months dry period, from May to October. Associated regional paleoenvironment is mainly characterized by Mediterranean forests, woodlands, and scrub, and the potential tree coverage is around 25%, that is, much less forested than today. New estimates agree with the ‘Iberian’ hominin ecological model, and with other proxies (large mammals, small mammals and archaeobotanical remains) that indicate a period of increased aridity contemporaneous with human occupations of the site.
•Dmanisi is one of the oldest Early Paleolithic sites discovered out of Africa.•Climate is newly reconstructed as Mediterranean warm and semi-arid.•New estimates however suggest warmer temperatures than previously reconstructed.•Paleoenvironment is characterized by Mediterranean forests, woodlands, and scrub.•Mediterranean biome was a suitable place for early hominins as early as 1.8 Ma.
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 δ2H and δ13C, 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.
•New palaeoenvironmental data for Neanderthal site of Abric del Pastor is presented.•Degradation of n-alkanes linked to anthropogenic fire.•Occupations in S.U. IVd occurred in generally cold and dry conditions.•The Barranc del Cinc acted as a vegetation refugium.•Occupation of rock shelter may have been strategically motivated by its location.
Amphibians are considered excellent indicators of ecological and climatic changes with a remarkable phenotypic plasticity. The study of such adaptative capacities is central to understanding the ...climate and environmental changes that occurred during the Early-Middle Pleistocene Transition, at around 1.2 Ma, when the persistence of subtropical ecosystems in Europe came to an end, and several reptile and tree taxa were extirpated. The SE Spain sites in the Guadix-Baza Basin offer an exceptional opportunity for studying this change, in addition to the significant findings made in this area in the field of human evolution.
We have analysed the body size of the most well-represented amphibian species in the sites, the Iberian waterfrog, Pelophylax perezi. In order to reconstruct past body sizes from fossil samples, a regression model from current osteological collections has been generated. Also, diversity of the herpetofauna community was studied at different levels as richness or species number. Finally, to study the relationships between body size, richness, climate and productivity, OLS regression models and Pearson correlations were applied. Also for this purpose, a productivity indicator was designed based on the addition of the two most productive ecosystems from previous habitat reconstruction.
Amphibian body size appears to be negatively associated with primary productivity, reaching minimum values during the interglacial stages, when species richness increased. In contrast, during glacial periods characterised by greater aridity and fewer resources, amphibian body size increased while species richness decreased. Main explanations proposed to justify this pattern are the “water-availability hypothesis” and a trade-off between somatic growth and reproductive opportunities for females. The study of herpetofaunal diversity shows a clear correlation to regional plant diversity and primary productivity. The results of this work indicate that species richness and amphibian body size are valuable proxies that can complement current environmental and climate reconstruction methods.
•Somatic growth and reproduction: the trade-off which determines amphibian body size.•Amphibian body size decreases towards more productive ecosystems.•Primary productivity determines species richness.•Frog body size is defined as a new indicator of Pleistocene ecosystem conditions.
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