Pliocene to Middle Pleistocene climate history in the Guadix-Baza Basin, and the environmental conditions of early Homo dispersal in Europe

Pliocene to Middle Pleistocene climate history in the Guadix-Baza Basin, and the environmental conditions of early Homo dispersal in Europe Juha Saarinen a , * , Otto Oksanen a , Indr_ e Zliobait_ e a , Mikael Fortelius a , b , Daniel DeMiguel c , d , Beatriz Azanza e , Herv e Bocherens f , Carmen Luz on g , Jos e Solano-García h , Jos e Yravedra i , Lloyd A. Courtenay j , Hugues-Alexandre Blain k , l , Christian S anchez-Bandera k , l , Alexia Serrano-Ramos g , Juan Jos e Rodriguez-Alba m , Suvi Viranta a , Deborah Barsky k , l , Miikka Tallavaara a , Oriol Oms n , Jordi Agustí k , l , o , Juan Ochando p , Jos e S. Carri on p , Juan Manuel Jim enez-Arenas q a University of Helsinki, Finland b Visiting Scholars Program, University of Granada, Granada, Spain c ARAID / Universidad de Zaragoza. Departamento Ciencias de La Tierra, Zaragoza, Spain d Institut Catal a de Paleontologia Miquel Crusafont, Universitat Aut onoma de Barcelona, Barcelona, Spain e Universidad de Zaragoza, Departamento Ciencias de La Tierra, Instituto Universitario de Investigaci on en Ciencias Ambientales de Arag on (IUCA), Zaragoza, Spain f Universit€ at Tübingen, Germany and Senckenberg Centre for Human Evolution and Palaeoenvironment, Tübingen, Germany g Universidad de Granada, Programa de Doctorado en Historia y Artes, Spain h Department of Prehistory and Archaeology, University of Seville, Spain i Departamento de Prehistoria, Historia Antigua y Arqueología Universidad Complutense de Madrid, Spain j Department of Cartographic and Terrain Engineering, Higher Polytechnic School of  Avila, University of Salamanca, Hornos Caleros 50, 05003,  Avila, Spain k Institut Catal a de Paleoecologia Humana I Evoluci o Social (IPHES-CERCA), Zona Educacional 4, Campus Sescelades URV (Edifici W3), 43007, Tarragona, Spain l Universitat Rovira I Virgili, Departament D’Hist oria I Hist oria de L’Art, Avinguda de Catalunya 35, 43002, Tarragona, Spain m Departamento de Paleontología, Facultad de Ciencias Geol ogicas, Calle Jos e Antonio Novais, 2, Universidad Complutense de Madrid, 28040, Madrid, Spain n Universitat Aut onoma de Barcelona, Spain o ICREA, Instituci o Catalana de Recerca I Estudis Avançats, Pg. Lluís Companys 23, 08010, Barcelona, Spain p University of Murcia, Faculty of Biology, Department of Plant Biology, Murcia, Spain q Universidad de Granada, Departamento de Prehistoria y Arqueología / Instituto Universitario de La Paz y Los Conflictos, Granada, Spain article info Article history: Received 20 May 2021 Received in revised form 30 July 2021 Accepted 30 July 2021 Available online 13 August 2021 Handling Editor: Mira Matthews Keywords: Pleistocene Palaeoclimatology Vegetation dynamics Hominin environments Large mammals Ecometrics Mesowear abstract The Guadix-Baza Basin (GBB) in Andalucía, Spain, comprises palaeontological and archaeological sites dating from the Early Pliocene to the Middle Pleistocene, including some of the earliest sites with evidence for the presence of early humans (Homo sp.) in Europe. Thus, the history of climate and environments in this basin contributes significantly to our understanding of the conditions under which early humans spread into Europe during the Early Pleistocene. Here we present estimates of precipitation and primary productivity in the GBB from the Pliocene to the Middle Pleistocene based on dental ecometrics in fossil communities of large herbivorous mammals, and perform an ecometrics-based distribution modelling to analyse the environmental conditions of Early and Middle Pleistocene human sites in Europe. Our results show that Early Pleistocene humans generally occupied on average relatively diverse habitats with ecotones, such as woodlands and savannas, but avoided very open and harsh (cool or dry) environments. During the Middle Pleistocene in Europe, humans occupied a comparatively much broader range of environments than during the Early Pleistocene, but were on average more concentrated in environments where the dental ecometric of mammals indicate wooded palaeoenvironments. In the earliest human occupation sites of the GBB, Barranco Le on and Fuente Nueva 3, the mean annual precipitation and net primary production estimates indicate climatic conditions close to modern Mediterranean sclerophyllous woodland environments, but with slightly higher primary productivity, *Corresponding author. E-mail address: juha.saarinen@helsinki.fi(J. Saarinen). Contents lists available at ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev https://doi.org/10.1016/j.quascirev.2021.107132 0277-3791/©2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Quaternary Science Reviews 268 (2021) 107132 Europe Guadix-baza basin indicating some similarity with East African woodlands. On the other hand, the environments did not resemble African grassland savannas. The browse-dominated diets of ungulates from Barranco Le on and Fuente Nueva 3 further suggest palaeoenvironments where grasses were a minor component of the vegetation. In the slightly older site of Venta Micena that has no evidence for the presence of hominins, dental ecometric estimates indicate climate and environments similar to Mediterranean “forest steppe” environments existing in the surroundings of Baza today. Grasses were prevalent in the diet of some taxa, especially equids, in Venta Micena, but most of the species show browse-dominated diets even there. ©2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). 1. Introduction Understanding the environmental conditions under which early humans dispersed into Iberia during the Early and Middle Pleistocene is a key issue for understanding what enabled them to expand and how they interacted within different environments. Dental ecometrics and body size of large herbivorous mammals have been associated with various aspects of vegetation and climate (Fortelius et al., 2002,2016;Liu et al., 2012;Saarinen, 2014;Saarinen et al., 2016; Zliobait_ e et al., 2016; Zliobait_ e et al., 2018;Oksanen et al., 2019). Here we use dental ecometric variables and mean body size in fossil ungulate communities to predict presence of humans (species distribution of humans) during the Early and Middle Pleistocene in Europe. The model is calibrated on fossil and archaeological evidence from Pleistocene localities of Europe. Much of the debate about the environmental conditions during these episodes of earliest human dispersions has centered around the question of whether they occurred in the context of grasslands or wooded grasslands, similar to African grassland savannas (the “savannahstan”-hypothesis; Dennell and Roebroeks, 2005), or rather in woodlands or even closed forests (Belmaker, 2010a,b; Dennell, 2010;Levin, 2015;Patterson et al., 2017a,b;Belmaker and O'Brien, 2018). Also, the importance of water-edge habitats for early humans has been discussed (Cohen et al., 2012). Early human evolution in the Early Pleistocene of East Africa took place in the broad context of opening landscapes and the spread of C4 grasses, but in fact the environments where early humans occurred were diverse, with fine-scale spatial and temporal variation in woody cover (Carri on et al., 2011, 2019;Levin, 2015;Patterson et al., 2017a,b). It has been suggested that the earliest human expansion out of Africa into Southern and Eastern Asia occurred in grassland, wooded grassland and woodland habitats similar to modern African savannas (Dennell and Roebroeks, 2005;Dennell, 2010). However, this “savannahstan-hypothesis”sensu stricto is not consistently supported by multi-proxy analyses of environmental conditions in the Early Pleistocene human occupation sites in Eurasia. Based on indicator species and ecological diversity analysis, it has been suggested that the earliest human occurrence sites in Eurasia, such as Dmanisi (Georgia), and ‘Ubeidiya (Israel), had palaeoenvironments similar to African savannas (Dolukhanov, 2000;Palmqvist, 2002;Martínez-Navarro, 2004). However, taxonomic diversity measurements using correspondence analyses indicate that their palaeoenvironments differed from African savannas, comprising instead a mixture of temperate forest and Mediterranean woodland elements (Belmaker, 2006, 2010a, b). Other palaeoenvironmental proxies from Dmanisi (such as pollen, phytoliths and carpological remains) indicate landscapes that could be interpreted to be savanna-like in a physiognomic or structural sense, but not taxonomic sense, being instead dominated by temperate oak forest elements with grassy vegetation (Messager et al., 2010). Mesowear analysis of the ungulate fauna in ‘Ubeidiya further supports a wooded palaeoenvironment, being dominated by ungulates with browsing diets (Belmaker and O'Brien, 2018). Moreover, the earliest human occupation sites in Eastern Asia do not appear to have been consistently savanna-like. For example, the palaeoenvironments in the Nihewan basin (ca. 1.7e1 Ma) included elements of temperate woodlands and grasslands (Peterson et al., 2003;Teague and Potts, 2007), while the palaeoenvironment of Gonwangling (ca. 1.2 Ma) has been interpreted as subtropical montane forest (Teague and Potts, 2007). 1.1. Research history of climate and palaeoenvironments in the Guadix-Baza Basin during the pleistocene The Guadix-Baza Basin (GBB) (Andalucía, Spain) is a sedimentary basin, with an extensive record of palaeontological and archaeological sites ranging from the Pliocene to the Middle Pleistocene (ca. 4.5e0.4 Ma), including Barranco Le on and Fuente Nueva 3 (ca. 1.4e1.2 Ma), which are among the earliest sites with solid evidence of the presence of humans (Homo sp.) in Europe (Toro-Moyano et al., 2013). Somewhat contradictory palaeoenvironmental information from the Pleistocene sites in the GBB has been published based on different methods. For example, Palmqvist et al. (2003) interpreted the palaeoenvironment of Venta Micena to have been similar to East African savannas on the basis of faunal analysis, whereas a Mediterranean woodland environment was suggested by Belmaker (2006). Most analyses indicate a predominance of Mediterranean woodland and open environments in the basin during much of the Early Pleistocene (e.g., Alberdi et al., 2001;Belmaker, 2006, 2010a;Agustí et al., 2010;Blain et al., 2011;S anchez-Bandera et al., 2020;Altolaguirre et al., 2020, 2021). The presence of the Baza palaeolake, and changes in its water-level, have been key elements affecting the palaeoecology of the basin, by providing a constant supply of water and palustrine environments around the lake (Oms et al., 2011). Furthermore, the “Galerian turnover pulse”in mammal faunas (ca. 1.0e0.9 Ma) has been associated with the arrival of early humans in Europe (Azanza et al., 2000), although many of the earliest European sites, including Barranco Le on and Fuente Nueva 3, now seem to predate this event. Nonetheless, the arrival of some new species, such as the very large cervid Praemegaceros verticornis (that was proposed as the marker of the Galerian Mammal Age; Gliozzi et al., 1997) and the large equid Equus suessenbornensis, may be associated with the arrival of early humans, suggesting perhaps either a common dispersal event or a change of environmental conditions that favoured the dispersal of these taxa in Europe. In the northern margin of the GBB, on the Baza palaeolakeshore, swampy conditions are reconstructed at the earliest Pleistocene site of Hu elago (ca. 2.6 Ma) as indicated by the depositional environment, taphonomy and the abundance of browsing large herbivores in the mammal fauna. All this evidence suggests abundant wooded or bushy environments in the surroundings (Alberdi et al., 2001). Similarly, both the late Early Pleistocene site of Hu escar 1 (ca. 1.1 Ma according to Alberdi et al., 2001;900e800 ka according to Rodríquez et al., 2015, and 574e410 ka according to (Demuro et al., 2015)) and the early Middle Pleistocene site of J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 2 Cúllar-Baza 1 (0.7 Ma) have palustrine depositional environments and diverse faunas of browsing ungulates. This indicates a swampy lake-shore environment, surrounded by woodlands or shrublands in Hu escar 1, but the lack of closed-forest mammal taxa indicates open, sparsely forested environments with dry periods (Alberdi et al., 2001). Near the village of Orce, the sites of Venta Micena (VM), Barranco Le on (BL) and Fuente Nueva 3 (FN3) provide essential data for contributing to discussions about the early human occupation of Europe. Despite intensive excavations, the oldest of these sites, VM, dated to ca. 1.6e1.4 Ma (Duval et al., 2010), has not yielded any conclusive evidence for the presence of early humans. In contrast, abundant Oldowan stone tools and bones with anthropogenic modifications have been discovered in BL (1.81e1.05 [1.43 ±0.38], Barsky et al., 2010;Toro-Moyano et al., 2013;Blain et al., 2016; Espigares, 2019;Titton et al., 2020;Titton et al., 2021) and FN3 (1.4e0.98 [1.19 ±0.21], Barsky et al., 2010;Duval, 2008;Duval et al., 2012;Espigares, 2019). In addition, BL yielded a fossil human tooth (Toro-Moyano et al., 2013). Palustrine depositional environments near the Baza lakeshore have been evidenced for all these sites (Oms et al., 2011). The palaeoenvironment in VM was interpreted as similar to African savannas by Palmqvist et al. (2003), based on analyses of feeding ecology and locomotion types of large mammals. However, taxonomic correspondence analysis of large mammals (Belmaker, 2006, 2010a) indicates that the palaeoenvironment comprised elements of Mediterranean woodlands and temperate forests and was thus quite different from African savannas. Rodent faunas indicate that the precipitation and temperature in VM were roughly similar to present (Agustí et al., 2010). The reconstructions of palaeoclimate and palaeoenvironments for BL and FN3 indicate temperature conditions similar to present, but higher precipitation, with Mediterranean woodland/shrubland -type vegetation (Agustí et al., 2009,2010;Blain et al., 2011,2016; S anchez-Bandera et al., 2020). The vegetation type in level D1 at Barranco Le on, containing most of the faunal remains and evidence of human presence in BL, is described as a wooded environment. In contrast, the environmental conditions at FN3 are now reconstructed as more open and dryer than at BL, based on the amphibian and reptile fauna (S anchez-Bandera et al., 2020). In this study we provide further information about the palaeoenvironmental conditions in the GBB from the Early Pliocene (ca. 4.5 Ma) to the Middle Pleistocene (ca. 0.4 Ma), based on dental ecometrics, average body size and diet of large herbivorous mammals. We further discuss the palaeoenvironments of the earliest human occupation sites, BL and FN3, in the wider context of early human palaeoenvironments in Europe, based on distribution modelling of preferred environments during the Early and Middle Pleistocene of Europe. 2. Materials and methods 2.1. Materials The mammal fossils from Venta Micena, Barranco Le on and Fuente Nueva 3 used in this study are housed in the Archaeological Museum of Granada, Andalucía, Spain. Large mammal faunal lists of European Early and Middle Pleistocene fossil mammal localities and archaeological sites were collected from literature (references in Supplementary Table S1). Stratigraphic and sedimentological data for the GBB were also collected. In total, dental ecometric values and mean body size indices from 12 localities from the GBB and altogether 92 Early and Middle Pleistocene European localities were used in this study (Supplementary Tables S1 and S2). The localities were chosen based on the following criteria: 1) the fauna include at least 5 species of large herbivorous mammals, 2) the mammalian fauna and the possible evidence of human occupation can be shown to be associated, as far as can be told from the stratigraphy, 3) the fossil assemblage does not show obvious irregularities due to sorting by human or carnivore activities, or due to other taphonomic processes. 2.2. Dental ecometric trait data We use dental ecometric traits within large mammal communities to model mean annual temperature (MAT), minimum annual temperature (MINT), mean annual precipitation (MAP) and net primary production (NPP) of GBB localities and other Early and Middle Pleistocene European localities. Such an approach is taxonfree (Damuth, 1992) in the sense that the inference of past conditions is based on generalised dental ecometric traits rather than individual adaptations of taxa, even if the traits are coded at species-level and are in this sense based on species lists per localities. It has been demonstrated that dental ecometric traits are not significantly influenced by non-ecological processes such as phylogenetic concervatism or spatial autocorrelation, and are instead primarily driven by climatic variables (Lawing et al., 2017). Dental ecometric traits for the large herbivorous mammal species present in the GBB and other locations in Early and Middle Pleistocene Europe were determined following the coding of Liu et al. (2012) and Zliobaite et al. (2018). The dental ecometric traits were observed from second upper molar in ungulates, or from the third upper molar in pigs and proboscideans. The traits were scored at the species level. They include: - Hypsodonty, HYP (tooth crown height): 1 (brachydont), 2 (mesodont) or 3 (hypsodont). Hypsodonty is an adaptation for increasing functional durability of dentition. Mean ordinated hypsodonty in large mammal communities is correlated with precipitation through the link of high abrasion on teeth in dry climatic conditions, possibly because of multiple factors, including aeolian dust accumulation and prevalence of grasses with phytoliths in dry environments (e.g., Fortelius et al., 2002;Liu et al., 2012). - Longitudinal loph count, LOP: the number of elongated cutting edge structures that are oriented in the direction of the tooth row (for example rhinoceroses have one (the ectoloph), ruminants and horses have two (the buccal and lingual “lophids”formed by the flattened cusps), and proboscideans have none (because all the lophs are transverse)). LOP is correlated with temperature (high LOP value indicating cool climate), because longitudinal lophs are most abundant in ungulates feeding seasonally on bark and branches of deciduous trees that drop their leaves during cold months (e.g., Liu et al., 2012). - Horizodonty (HOD): the amount of transverse cusp pairs or lophs; the categories are: 1 (brachyhorizodont: two cusp pairs or lophs, this includes most herbivorous mammals), 2 (mesohorizodont: three cusp pairs or lophs, this happens e.g. in some pigs with enlarged last molars), 3 (hypsohorizodont: more than three cusp pairs or lophs, this includes mostly mammutids, gomphotheres and elephants, and some derived pigs such as warthog). Horizodonty is associated with increase in tooth volume by increasing lophs or cusp pairs, and is associated with functional durability of dentition (Zliobaite et al., 2016). - Presence of acute lophs (AL): 1 (present), 0 (absent); these are sharp, cutting lophs that maintain sharp facets when worn, such as the ectoloph of most rhinos, the chisel-like lophs of tapirs, and the sharp buccal lophs of most cervids,but e.g. horses and almost all (hypsodont) bovids lack these. Acute lophs are typical for browsers in forested environments (Zliobaite et al., 2016; 2018) If in doubt, AL for selenodonts is assigned if mesowear is sharp. The proportion of acute lophs in a community is correlated with temperature today, as it is highest in deciduous forest communities where most J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 3 ungulate species cut branches when leaves are dropped during cold season (see also Oksanen et al., 2019). - Presence of obtuse lophs (OL): 1 (present), 0 (absent); these are “blunt”lophs that become basin-like without maintaining sharp facets when worn (e.g., the transverse lophs in rhinos, hippos, gomphotheres and elephants, and most of the “lophs”in bovids and equine horses). - Structural fortification of cusps (SF): 1 (present), 0 (absent); these are any morphological features of the cusps that make the cusp stand out from the occlusal surface (by resisting wear) in worn teeth. The most typical examples of such structures are: buccal cusps with bulbous, thickened lingual enamel loops in some ruminants (e.g. reduncine antelopes and bovines), cusps with heavily folded enamel (e.g. in many pigs such as Sus scrofa), and molars with raised central ridges formed by conules or thickened enamel edges (e.g. in Hippopotamus). Structural fortification occurs in modern herbivorous mammal communities in fresh-grass grazers and mixed-feeders in wooded habitats, primarily in forests and wetlands, and are thus indicators of such habitats (Zliobaite et al., 2018). - Occlusal topography (OT): 1 (flat), 0 (non-flat); this refers to the overall shape of the worn occlusal surface of the teeth in buccolingual direction. Flat occlusal topography is typical for grazing ungulates such as horses. -Plain selenodonty (PS): 1 (present), 0 (absent): this is a combination of traits where longitudinal loph count is 2, only obtuse lophs are present, there is no structural fortification, no coronal cement and the occlusal topography is non-flat. This dental morphology type is particularly abundant in ruminants and camels inhabiting relatively harsh environments, such as deserts and montane environments. -Bunodonty (BUN): 1 (present), 0 (absent); bunodonty refers to dental morphology with separate cusps that are not fused into elongated, loph-like structures. This dental morphology type is typical for omnivores and frugivores such as most suids and primates. High proportion of bunodont taxa indicates relatively warm and humid forest environments. We used mesowear analysis (Fortelius and Solounias, 2000) for reconstructing the dietary composition of herbivorous mammals in an attrition-abrasion (browse vs. grass) continuum for the three localities from the vicinity of the village of Orce, Venta Micena, Barranco Le on and Fuente Nueva 3. Average mesowear signal in the ungulate communities from the Orce sites provides further information about the vegetation type at the Orce sites. The mesowear method is based on scoring the relief and shape of worn ungulate molar teeth, which reflects the degree of abrasion caused by grass on the molar surface, and allows comparing the dietary composition in the fossil ungulate populations with known diets of extant ungulates by hierarchical clustering (Fortelius and Solounias, 2000). Mesowear was scored at the specimen-level. The hierarchical clustering was performed using Ward's method with Euclidean distances. The clustering was performed in twodimensional space, based on the shape and relief scores of the traditional mesowear scoring system of Fortelius and Solounias (2000). 2.3. Locality mean body size indices In addition to the dental ecometric traits (crown types and mesowear), body mass estimates were calculated for a large set of large herbivorous mammals from the 92 Early and Middle Pleistocene European localities. Relative body size indices were calculated for each locality by calculating the mean body mass of ungulate species within each locality and dividing these locality means with the highest mean body mass in the total set of localities. For the body mass estimates, we used primarily postcranial bone measurements utilising the regression equations of Scott (1990) for bone measurements and body mass in modern ungulates, and Christiansen (2004) for proboscideans. These were complemented by body mass estimates based on second upper and lower molar lengths for taxa for which postcranials were not available, using the equations of Janis (1990). Relative body size indices were calculated for each of the 92 Early and Middle Pleistocene localities. This was done using the following method: 1) Measurements of postcranial bones or molar teeth were obtained from the literature (or measuring in museums by JS) and used for calculating body mass estimates (preferably for populations of the species within localities, but if measurement data of a species was lacking for a locality, total mean body mass estimate for the species was used instead). 2) Mean body mass was calculated for each locality as the mean value of the body mass estimates of each ungulate species in the locality (palaeopopulations). 3) Relative body mass indices (BMloc) were calculated for each locality by dividing their mean body mass value with the largest mean body mass value in the total set of 92 localities. Thus, the locality with the largest BMloc has the value 1, and all the other localities have values between 0 and 1. The mean body mass indices of the localities were then used in the human distribution modelling analysis as an additional ecometric trait, as average body size of ungulates correlates with habitat openness on one hand, and resource quality and availability on the other hand (see Saarinen, 2014;Saarinen et al., 2016). Proboscidea was omitted from the body size categories because of lack of resolution in the body mass estimate data. The normalised body mass indices for the localities are composite values that take into account the relative size of the species (whether on average small- or large-sized species are dominant in the localities) and for abundantly sampled species, body mass variation within species. 2.4. Mean annual precipitation, mean annual temperature and net primary production estimates for the pliocene epleistocene of Guadix-Baza Basin Mean annual precipitation and net primary productivity in the GBB localities ranging from the Pliocene (ca. 4.5 Ma) to the Middle Pleistocene (ca. 400 ka) were estimated based on hypsodonty, longitudinal loph count and presence of acute lophs, averaged in the large herbivorous mammal assemblages, using the equations by Oksanen et al. (2019). Based on these estimates, the climate history in the GBB from the Early Pliocene to the Middle Pleistocene is discussed. The equations for the estimation are: Mean annual temperatureðMATÞ¼27 :28:5AL Mean temperature of coldest monthðMINTÞ¼18 :42:9AL Mean annual precipitationðMAPÞ¼2:491 289HYP 841LOP Net primary productionðNPPÞ¼2601 144HYP 935LOP The climatic variables (MAT, MINT and MAP) for the modern surroundings of Baza were obtained from long-term weather observation data (https://en.climate-data.org/europe/spain/ andalusia-252/). NPP for the modern Baza area was estimated from dental ecometrics of a combined species assemblage of wild ungulates and domestic ungulates that are herded in that region today. This approach is justified based on the observation that adding feral domestic ungulates in dental ecometrics -based J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 4 estimates of climate and vegetation type compensate for the bias in the ecometric signal caused by the loss of ungulate species by human interference, for example as has been observed in the Sahel today (Zliobaite et al., 2018). The MAP, MINT and NPP estimates of the GBB localities based on dental ecometrics were compared with both estimated and measured values for modern biomes and ecosystems using hierarchical clustering. For the comparisons, dental ecometric estimates of MAP, MINT and NPP were calculated for selected modern IUCN sites from Eurasia, North America and East Africa, and several Early and Middle Pleistocene early human sites from Africa, in order to evaluate the similarity of the GBB sites with modern environments and African early human sites (Supplementary Table S3). In addition, measured MAP, MINT and NPP values for the modern biomes were calculated from the values reported by Olson et al. (2013) and compared with the dental ecometric estimates of MAP, MINT and NPP of the GBB sites (Supplementary Table S4). The hierarchical clustering was performed using Ward's method, with the Euclidean distances. The MAP, MINT and NPP values were normalised for the hierarchical clustering analyses. The IUCN sites for the comparison of ecometric estimates from the Pliocene and Pleistocene GBB localities were chosen to represent a wide range of modern environments that are relatively undisturbed by human activities and contain diverse large herbivorous mammal faunas, including boreal forests (Nahanni NP and British Columbia), boreal forest-grassland mosaic (Yellowstone), European temperate forest (Bialowieza NP), Mediterranean high-altitude forest (Sierra Nevada NP), Mediterranean lowaltitude woodland/shrubland (near Baza), and a series of tropical African environments from rainforest (Nouabale-Ndoki NP) to grassland savanna (Serengeti) and dry shrubland/woodland (near Nairobi). In addition, dental ecometric estimates from a wide range of African early human sites were chosen for comparison, including Lake Turkana region, Kenya, Olduvai, Tanzania and Swartkrans, South Africa (Supplementary Table S3). To complement the hierarchical clustering analysis of the GBB sites, we use MAP ranges of modern Mediterranean biomes (Qu ezel and M edail, 2003;Suc and Popescu, 2005) as a further reference point for discussing the palaeoenvironments of the GBB sites. 2.5. Modelling of the environmental conditions under which early humans occurred in the early eMiddle Pleistocene in europe For the modelling of early human habitats in Early and Middle Pleistocene in Europe, we used a tailored species distribution modelling approach. The modelling task was to predict the probability of presence or absence of humans based on ecometric contexts of large mammal communities on sites. The model itself was a logistic regression fit via generalised linear modelling. The presence/absence of humans was coded for 92 Early and Middle Pleistocene palaeontological and archaeological localities from Europe, and dental ecometric traits of large herbivorous mammals were used as the predictive variables for the probability of human presence. We experimented on the analysis using different combinations of traits in the analysis (but with a maximum of 5 traits at time to avoid overfitting) and ended up with a model using hypsodonty (HYP), acute lophs (AL), structural fortification (SF) for Early Pleistocene and Middle Pleistocene localities, and HYP, AL, SF and locality mean body size indices (BM) for the complete set of localities. We evaluated how well the model predicts presence of humans by applying a leave-one out approach to compute the average Area Under the Roc Curve (Fielding and Bell, 1997). In addition, we used mean absolute errors and confidence statistics over the wrights og input variables in the models to compare the performance of the models. We performed principal component analyses (PCA) to further explore the effect of ecometric traits on the presence/absence of humans in Early Pleistocene and Middle Pleistocene localities separately, and the presence of Early Pleistocene, early Middle Pleistocene and late Middle Pleistocene human sites in the complete set of localities. This was done in order to compare the relative and common associations of the ecometric traits with human presence. Partial per cent contribution of the ecometric traits on the principal components were used for evaluating the significance of associations of the constituent ecometric traits on human presence, and generalised conclusions about the environmental conditions of most Pleistocene European human presence sites are discussed based on this analysis. 3. Results 3.1. Pliocene to Middle Pleistocene history of climate and net primary production in the Guadix-Baza Basin Mean annual precipitation (MAP) and net primary production (NPP) estimates based on dental ecometrics in large herbivorous mammal communities indicate a drastic decline from ca. 870 to ca. 450 mm/a in MAP and from ca.1130 to ca. 700 g(C)/m 2 /a in NPP from the Early Pliocene of Baza 1 (ca. 4.6 Ma) to the Plio-Pleistocene boundary of Hu elago (ca. 2.6 Ma) in the GBB (Table 1,Fig. 2). After this, Fuente Nueva 1 (ca. 2.2 Ma) and Fonelas P-1 (ca. 2 Ma) as well as Venta Micena (ca. 1.6 Ma) have the lowest estimated MAP and NPP, while Barranco del Paso (ca. 1.8 Ma) with intermediate age has relatively high MAP and NPP estimates. After the drop at ca.1.6 Ma in Venta Micena, the MAP and NPP estimates become more homogenous and equable, ranging from ca. 600e700 mm MAP and 900e1050 g(C)/m2/year NPP. The MAP in the GBB today is around 450 mm (ca. 470 mm in Guadix (https://en.climate-data.org/europe/ spain/andalusia/guadix-57014/), ca. 430 mm in Baza (https://en. climate-data.org/europe/spain/andalusia/baza-56902/)), which is similar to the estimated value for Fuente Nueva 1 and Venta Micena, while the rest of the Pleistocene localities in the GBB are estimated to have higher mean annual precipitation values. Also the NPP value of modern surroundings of Baza, including semi-feral domestic ungulates, is similar to the estimated values for Fuente Nueva 1 and Venta Micena (Table 1). In the hierarchical clustering of dental ecometric-based MAP, MINT and NPP estimates, Venta Micena and Fuente Nueva 1 consistently cluster together with modern surroundings of Baza (Fig. 3 a and b), and with modern Mediterranean oak and pine woodland biomes (Fig. 3 b). Hu elago and Fonelas P-1, together with Dmanisi, consistently form a cluster of their own next to the cluster containing modern Baza and Mediterranean forests in Fig. 3 a and b. Baza 1, Solana del Zamborino and Barranco del Paso cluster together with Bialowieza forest and Sierra Nevada National Park, indicating temperate forest-dominated palaeoenvironments. The rest of the GBB sites, including BL and FN 3, form a cluster of their own together with modern African woodland/shrubland and some Pleistocene African sites, and this cluster is separate from modern African grassland savanna (Serengeti plains) and most of the Pleistocene East African hominin sites (Fig. 3 a). Also ‘Ubeidiya, Israel, clusters together with these sites. A further comparison of the MAP values of the GBB sites with MAP ranges of modern Mediterranean biomes (Qu ezel and M edail, 2003;Suc and Popescu, 2005) indicates that Hu elago, Fuente Nueva 1, Fonelas P-1, Mencal 9 and Venta Micena, together with modern environment of Baza, fall within the range of modern “forest steppe”with Artemisia,Pinus halepensis and scarce evergreen Quercus (Table 1). In contrast, Barranco del Paso, Fuente Nueva 3, Barranco Le on, Hu escar 1 and Cúllar-Baza 1 are within the range of J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 5 evergreen forests dominated by sclerophyllous Quercus and Pinus, and Baza 1 and Solana del Zamborino have higher MAP values indicating affinity with mixed forest of deciduous Quercus,Fagus and conifers (Table 1). We consider these vegetational interpretations as further reference to the vegetation at the GBB sites, but note that these are likely to be oversimplified as they do not take into account temperature and NPP (see Discussion). 3.2. Mesowear analysis of the large herbivorous mammals from the orce sites The results show that most of the Orce ungulate species from all the three localities (Venta Micena, Fuente Nueva 3 and Barranco Le on) are clustered with extant ungulates that have predominantly browsing and browse-dominated diets (Fig. 4, see Supplementary Table S5 for a summary of mesowear results of the Orce ungulates). Only Equus altidens shows mesowear signals that in VM indicate purely grazing diet similar to extant zebras and white rhinoceros, and in BL and FN3 grass-dominated but mixed diet similar to extant saiga antelope and rock hyrax. Abundance of sharp cusps but low relief in E. altidens molars from BL and FN3 indicates a significant dietary element of some sort of tough vegetation that was not very abrasive. Somewhat surprisingly, the larger species of horse, Equus suessenbornensis, from BL and FN3 have mesowear signals similar to extant browsers such as moose and Javan rhinoceros, although they are represented by relatively small sample sizes. There is a slight but interesting difference between Venta Micena and the rest of the Orce sites, especially in the estimated diet of the horses: the browsing large species of horse (E.suessenbornensis) is absent from Venta Micena and the diet of the smaller species, E. altidens, is more grass-dominated in VM than in the other sites. Table 1 Mean annual precipitation (MAP), minimum annual temperature (MINT) and net primary production estimates for the GBB sites, based on mammalian dental ecometrics (Oksanen et al., 2019). Modern MAP and MINT values for the vicinity of Baza are from climate observation data (https://en.climate-data.org/europe/spain/andalusia/baza- 56902/) and the modern NPP value is estimated from dental ecometrics of large wild and domestic ungulates occurring in the area today. The Mediterranean vegetation zones (Qu ezel and M edail, 2003) indicated in the last column are: 1) Forest-steppe with Artemisia,Pinus halepensis,Juniperus and scarce evergreen Quercus (250 <MAP <600 mm), 2) Evergreen forest with sclerophyllous oaks, Pinus pinaster and P. pinea (600 <MAP <800 mm) and 3) Mixed forest with deciduous oaks, Fagus and conifers (MAP >800 mm). Age (Ma) Locality presence of humans MAP (mm) MINT (  C) NPP (g(C)/ m 2 /a) vegetation type estimated from MAP range of modern Mediterranean vegetation zones (Qu ezel and M edail, 2003) 4.6 Baza 1 absent 873 [0] 1131 3 2.6 Hu elago absent 447 0.5 691 1 2.2 Fuente Nueva 1 absent 384 10 713 1 2 Fonelas P-1 absent 543 1.5 797 1 1.8 Barranco del Paso absent 678 1 975 2 1.7 Mencal 9 absent 538 13 882 1 1.6 Venta Micena absent 449 11 767 1 1.4 Barranco Le on present 602 8.5 914 2 1.2 Fuente Nueva 3 present 602 8.5 914 2 0.9 Hu escar 1 present? 708 12 1049 2 0.7 Cúllar Baza 1 present 602 8.5 914 2 0.4 Solana del Zamborino present 945 2 1221 3 0 Modern (around Baza) present 433 7 683 1 Fig. 1. Map of the Guadix-Baza Basin with the localities. J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 6 3.3. Early human (Homo sp.) habitat modelling based on dental ecometrics and body size of large herbivorous mammals We selected the following model for predicting human occurrence for the complete set of Early and Middle Pleistocene localities, based on estimated coefficients of dental traits, their p-values, accuracy as area under ROC and the mean absolute error: P (occurrence) ¼1/(1 þe-Z), where Z¼15.852 þ3.542*HYP þ10.662*SF þ9.526*AL þ5.327*BMloc. In the model for all Early and Middle Pleistocene localities, the strongest significant positive effect for the probability of human presence is given by percentage of the presence of acute lophs (AL), followed by percentage of structural fortification (SF) in the large mammal communities (Table 2). When the model is divided into Early Pleistocene and Middle Pleistocene separately, hypsodonty (HYP), structural fortification (SF) and acute lophs (AL) remain the most significant constituents of the model, but the model is different for Early Pleistocene and Middle Pleistocene. In the Early Pleistocene, the most significant positive correlation for the probability of human presence is provided by structural fortification, whereas in the Middle Pleistocene the most significant correlation is with acute lophs (Table 2.) Component 1 in the principal component analysis of human presence based on the traits corresponds to 46.5% of variation in human presence and it is contributed by the opposite effects of SF þAL þBMloc and PS þHYP (Fig. 5). Component 2 corresponds to 38.6% of the variation in human presence and is mainly driven by the opposite effects of PS and SF þBMloc. In general, human occurrence is concentrated in localities with high values of acute lophs (AL), structural fortification (SF), high mean body mass index of ungulates in localities (BM_loc), mean bunodonty (BUN) and mean horizodonty (HOD), moderate values of hypsodonty (HYP) and low values of plain selenodont ecomorphs (PS) (Appendix,Fig. A.1). The positive correlation with the presence of Early Pleistocene Homo sp. is dominated by the effects of high percentage of structural fortification and high locality mean body size index, while the correlation with the Middle Pleistocene humans varies more is more strongly driven by high percentage of acute lophs (Fig. 5). Furthermore, within the Middle Pleistocene, the Early Middle Pleistocene human sites are more associated with high percentage of acute lophs (AL) than the Late Middle Pleistocene localities (Appendix,Fig. A.1). Human habitat suitability scores were calculated based on the total dental ecometric model prediction for all the 92 Early and Middle Pleistocene European localities included in this study and compared with the presence or absence of humans in the localities. The human habitat suitability scores for the localities, ranked from highest to lowest, are presented in Supplementary Table S6. Since the model was fit on observed presence-absence data, the sites where the evidence for human presence is lacking generally have the lowest habitat suitability scores and sites where humans are present have the highest scores, but there are some notable exceptions to this pattern. Most notably, several localities with evidence for human presence have lower-than-average estimated habitat suitability scores (Atapuerca TE9c, Bisnik Cave, Visogliano, Orgnac 3, Caune de l’Arago, Pakefield, Swanscombe, Pirro Nord, Hoxne, Vallparadis, Dmanisi and Cúllar-Baza 1). Of these, Orgnac 3, cool stage levels of Caune de l’Arago and Bisnik Cave are Fig. 2. Mean annual precipitation and net primary production in the Guadix-Baza Basin from the Early Pliocene to the Middle Pleistocene as estimated from dental ecometrics of large herbivorous mammals using the equations published by Oksanen et al. (2019). J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 7 characterised by the presence of cold-climate taxa such as Coelodonta and Rangifer tarandus, indicating harsh climatic conditions in this respect. In contrast, some sites with no evidence for human presence have higher-than-average habitat suitability scores, suggesting that conditions there could have been suitable for humans, or more specifically, that condition there were quite similar to those where humans have found. Such sites without evidence for human presence but with high suitability estimates are the Early Pleistocene sites Colle Curti, Cesi, Castagnone and Monte Riccio in Italy and the early Middle Pleistocene sites of Mosbach and Prezletice in Central Europe. According to the model prediction, the Orce human sites Barranco Le on and Fuente Nueva 3 have a higher habitat suitability score for early humans than Venta Micena where evidence of human presence is lacking. The colour-interpolated maps of human habitat suitability scores in Europe through time indicate geographical patterns of habitat suitability that reflects the history of early human dispersals in Europe (Fig. 6). Some of the earliest indication of increase in habitat suitability for humans (as predicted by the model) occur in the first phase of Early Pleistocene (2.6e1.8 Ma) in Central Italy and Dmanisi, Georgia. During the second phase of Early Pleistocene (1.8e0.7 Ma) the areas of elevated human habitat suitability scores Fig. 3. Hierarchical clustering of the Pleistocene Guadix-Baza sites based on MAP, MINT and NPP estimated from dental ecometrics with a) dental estimates of MAP, MINT and NPP for modern IUCN sites and Pleistocene African hominine sites, and b) reported MAP, MINT and NPP for modern biomes (Chirici et al., 2007;Olson et al., 2013). The Euclidean distance values marking branch lengths are indicated for 11 first branches. The GBB localities in separate clusters are marked with different colours. Dmanisi and ‘Ubeidiya are included as examples of earliest Eurasian human sites outside the GBB. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 8 are centered in Israel, Spain, Northern Italy and in the Black Sea coast. During the early Middle Pleistocene, Central Europe and Southern England show a notable increase in the estimated human habitat suitability scores. In the late Middle Pleistocene, most of the European site have relatively high habitat suitability scores, except for a few sites indicating cold climatic conditions, such as Orgnac 3 (see Fig. 6). 4. Discussion The Guadix-Baza Basin in Andalucía, Spain, has particular relevance for the question of early human habitats and dispersals, as the archaeological and palaeontological sites of Barranco Le on and Fuente Nueva 3 (both ca. 1.4 Ma in age) have provided some of the earliest evidence for the presence of early humans (Homo sp.) in Europe (Toro-Moyano et al., 2013). Understanding the history of climatic and environmental conditions in the GBB and elsewhere in Fig. 4. Hierarchical clustering of mesowear of the Orce ungulates with extant ungulate species, based on percentage of high relief, percentage of sharp cusps and percentage of blunt cusps (following the methodology of Fortelius and Solounias, 2000). Dietary interpretations are based on known diets of the modern ungulate species in the clusters (see Fortelius and Solounias, 2000). The ungulate taxa from Barranco Le on (BL) are marked in green colour, the ones from Fuente Nueva 3 (FN3) in red, and the ones from Venta Micena (VM) in blue. The numbers in brackets indicate number of dental specimens used for each ungulate palaeopopulation from the Orce sites. Half square Euclidean distances are indicated for the first 10 clusters. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 9 Appendix Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.quascirev.2021.107132. References Agustí, J., Blain, H.-A., Cuenca-Besc os, G., Bailon, S., 2009. Climate forcing of first hominid dispersal in Western Europe. Journal of Human Evolution 57, 815e821. https://doi.org/10.1016/j.jhevol.2009.06.005. Agustí, J., Blain, H.-A., Furi o, M., de Marf a, R., Santos-Cubedo, A., 2010. The early Pleistocene small vertebrate succession from the Orce region (Guadix-Baza Basin, SE Spain) and its bearing on the first human occupation of Europe. Quat. Int. 223e224, 162e169. Agustí, J., Lordkidpanidze, D., 2019. An alternative scenario for the first human dispersal out of Africa. L’Anthropologie 123, 682e687. Alberdi, M.T., Alonso, M.A., Azanza, B., Hoyos, M., Morales, J., 2001. Vertebrate taphonomy in circum-lake environments: three cases in the Guadix-Baza Basin (Granada, Spain). Palaeogeogr. Palaeoclimatol. Palaeoecol. 165, 1e26. Altolaguirre, Y., Postigo-Mijarra, J.M., Barr on, E., Carri on, J.S., Leroy, S.A.G., Bruch, A.A., 2019. An environmental scenario for the earliest hominins in the Iberian Peninsula: early Pleistocene palaeovegetation and palaeoclimate. Rev. Palaeobot. Palynol. 260, 51e64. Altolaguirre, Y., Bruch, A., Gibert, L., 2020. A long early Pleistocene pollen record from Baza Basin (SE Spain): major contributions to the palaeoclimate and palaeovegetation of Southern Europe. Quat. Sci. Rev. 231, 106199. Altolaguirre, Y., Schulz, M., Gibert, L., Bruch, A.A., 2021. Mapping Early Pleistocene environments and the availability of plant food as a potential driver of early Homo presence in the Guadix-Baza Basin (Spain). J. Hum. Evol. 155, 102986.  Alvarez-Posada, C., Par es, J.M., Sala, M., Viseras, C., Pla-Pueyo, S., 2017. New magnetostratigraphic evidence for the age of Acheulean tools at the archaeopalaeontological site ‘Solana del Zamborino’(GuadixeBaza Basin, S Spain). Scientific Reports 7, 13495. https://doi.org/10.1038/s41598-017-14024-5. Anad on, P., Oms, O., Riera, V., Juli a, R., 2015. The geochemistry of biogenic carbonates as a paleoenvironmental tool for the Lower Pleistocene Barranco Le on sequence (BL-5D, Baza Basin, Spain). Quat. Int. 389, 70e83. Azanza, B., Alberdi, M.T., Prado, J.L., 2000. Large mammal turnover pulses correlated with latest Neogene glacial trends in the northwestern Mediterranean region. Geological Society, London, Special Publications 181, 161e170. Baena, J., Lordikpanidze, D., Cuartero, F., Ferring, R., Zhvania, D., Martín, D., Shelia, T., Bidzinashuili, G., Roca, M., Rubio, D., 2010. Technical and technological complexity in the beginning: the study of Dmanisi lithic assemblage. Quat. Int. https://doi.org/10.1016/j.quaint.2010.01.019. Barsky, D., Celiberti, V., Cauche, D., Gr egoire, S., Leb egue, F., de Lumley, H., Toro- Moyano, I., 2010. Raw material discernment and technological aspects of the Barranco Leon and Fuente Nueva 3 stone assemblages (Orce southern Spain). Quat. Int. 223e224, 201e219. Belmaker, M., 2006. Large Mammalian Community Structure through Time: ‘Ubeidiya as a Case Study. Ph.D. Dissertation. The Hebrew University of Jerusalem. Belmaker, M., 2010a. Early Pleistocene faunal connections between Africa and Eurasia: an ecological perspective. In: Fleagle, J.G., Shea, J.J., Grine, F.E., Baden, A.L., Leakey, R.E. (Eds.), Out of Africa I: the First Human Colonization of Eurasia. Springer, Dordrecht. Belmaker, M., 2010b. On the road to China: the environmental landscape of the Early Pleistocene in Western Eurasia and its implication for the dispersal of Homo. In: Norton, C.J., Braun, D.R. (Eds.), Asian Palaeoanthropology: from Africa to China and beyond, Vertebrate Palaeobiology and Palaeoanthropology. Springer, pp. 31e40. https://doi.org/10.1007/978-90-481-9094-2_3. Belmaker, M., O'Brien, H.D., 2018. Mesowear study of ungulates from the early Pleistocene site of ‘Ubeidiya (Israel) and the implications for early Homo dispersal from Africa. Quat. Int. 480, 66e77. Blain, H.-A., Bailon, S., Cuenca-Besc os, G., Benn asar, M., Rofes, J., L opez-García, J.M., Huguet, R., Arsuaga, J.L., Bermud ez del Castro, J., Carbonell, E., 2010. Climate and Figure A.1. Principal component analysis of localities with Early Pleistocene Homo, early Middle Pleistocene Homo and late Middle Pleistocene Homo, with effect of individual dental traits on the principal components. Early and late Middle Pleistocene Homo localities are concentrated on environments with relatively high SF, HOD and OT values, which early Midde Pleistocene Homo localities are associated with localities where average AL and BUN values are high. Localities without evidence for the presence of Homo are associated with high mean PS (only mean is indicated). J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 16 environment of the earliest West European hominins inferred from amphibian and squamate reptile assemblages: sima del Elefante Lower Red Unit, Atapuerca, Spain. Quat. Sci. Rev. 29, 3034e3044. Blain, H.-A., Bailon, S., Agusti, J., Martínez-Navarro, B., Toro, I., 2011. Palaeoenvironmental and palaeoclimatic proxies to the Early Pleistocene hominids of Barranco Le on D and Fuente Nueva 3 (Granada, Spain) by means of their amphibian and reptile assemblages. Quat. Int. 243, 44e53. https://doi.org/ 10.1016/j.quaint.2010.12.031. Blain, H.-A., Lozano-Fern andez, I., Agustí, J., Bailon, S., Men endez, L., Patrocinio, M., Ros-Montoya, S., Manuel, J., Toro-Moyano, I., Martínez-Navarro, B., Sala, R., 2016. Refining upon the climatic background of the early Pleistocene hominid settlement in western Europe: Barranco Le on and Fuente nueva-3 (Guadix- Baza Basin, SE Spain). Quat. Sci. Rev. 144, 132e144. Blain, H.-A., Fagoaga, A., Ruiz-S anchez, F.J., García-Medrano, P., Oll e, A., Jim enez- Arenas, J.M., 2021. Coping with arid environments: a critical threshold for human expansion in Europe at the Marine Isotope Stage 12/11 transition? The case of the Iberian Peninsula. J. Hum. Evol. 153, 102950. Bond, W.J., 2005. Large parts of the world are brown or black: a different view on the ‘Green World’hypothesis. J. Veg. Sci. 16, 261e266. Bradshaw, R.H.W., Hannon, G.E., Lister, A.M., 2003. A long-term perspective on ungulateevegetation interactions. For. Ecol. Manag. 181, 267e280. Carri on, J.S., Ochando, J., Fern andez, S., Munuera, M., Amor os, G., Blasco, R., Rosell, J., Finlayson, S., Giles, F., Jennings, R., Finlayson, G., Giles-Pacheco, F., Rodríguez- Vidal, J., Finlayson, C., 2018. Last neanderthals in the warmest refugium of Europe: palynological data from vanguard Cave. Rev. Palaeobot. Palynol. 259, 63e80. Carri on, J.S., Rose, J., Stringer, C., 2011. Early human evolution in the western Palearctic: ecological scenarios. Quat. Sci. Rev. 30, 1281e1295. Carri on, J.S., Scott, L., deMenocal, P., 2019. Paleofloras, Paleovegetation and human evolution. Rev. Palaeobot. Palynol. 267, 32e38. Chirici, G., Barbati, A., Maselli, F., 2007. Modelling of Italian forest net primary productivity by the integration of remotely sensed and GIS data. For. Ecol. Manag. 246, 285e295. Christiansen, P., 2004. Body size in proboscideans, with notes on elephant metabolism. Zoological Journal of the Linnean Society 140, 523e549. Cohen, K.M., MacDonald, K., Joordens, J.C.A., Roebroeks, W., Gibbard, P.L., 2012. The earliest occupation of north-west Europe: a coastal perspective. Quat. Int. 271, 70e83. Dallman, P., 1998. Plant Life in the World's Mediterranean Climates. University of California Press, Berkeley, CA. Damuth, J., 1992. Taxon-free characterization of animal communities. In: Behrensmeyer, A.K., Damuth, J.D., DiMichelle, W.A., Potts, R., Sues, H.D., Wing, S.L. (Eds.), Terrestrial Ecosystems through Time: Evolutionary Paleoecology of Terrestrial Plants and Animals. University of Chicago Press, Chicago, IL, pp. 183e203. Dennell, R.W., Roebroeks, W., 2005. An Asian perspective on early human dispersal from Africa. Nature 438, 1099e1104. Demuro, M., Arnold, L.J., Par es, J.M., Sala, R., 2015. Extended-range luminescence chronologies suggest potentially complex bone accumulation histories at the Early-to-Middle Pleistocene palaeontological site of Hu escar-1 (Guadix-Baza basin, Spain). Quaternary International 389, 191e212. Dennell, R.W., 2010. The colonization of “savannahstan”: issues of timing(s) and patterns of dispersal across Asia in the late Pliocene and early Pleistocene. In: Norton, C.J., Braun, D.R. (Eds.), Asian Palaeoanthropology: from Africa to China and beyond, Vertebrate Palaeobiology and Palaeoanthropology. Springer, pp. 7e30. https://doi.org/10.1007/978-90-481-9094-2_2. Dev es, M., Sturdy, D., Godet, N., King, G.C.P., Bailey, G.N., 2014. Hominin reactions to herbivore distribution in the lower Palaeolithic of the southern Levant. Quat. Sci. Rev. 96, 140e160. Dolukhanov, P.M., 2000. Microenvironments and the initial hominid settlement in Western Asia. In: Lordkipanidze, D., Bar-Yosef, O., Otte, M. (Eds.), Early Humans at the Gates of Europe. Li ege: Etudes et Recherches Arch eologiques de l'Universit edeLi  ege, pp. 93e98. Duval, M., 2008. Evaluation du potentiel de la m ethode de la datation par R esonance de Spin Electronique (ESR) appliqu ee aux gisements du Pl eistoc ene inf erieur:  etude des gisements d'Orce (bassin de Guadix-Baza, Espagne) et contribution  a la connaissance des premiers peuplements de l'Europe. PhD. Dissertation. Museum national d'Histoire naturelle de Paris. Duval, M., Toro-Moyano, I., Falgu eres, C., Mestour, B., Perrenoud, C., Patrocinio Espigares, M., Ros, S., 2010. Estudio litoestratigr afico del yacimiento arqueol ogico de Fuente Nueva 3 (Orce, cuenca de Guadix-Baza, Espa~ na). In: Toro-Moyano, I., Martínez-Navarro, B., Agustí, J. (Eds.), Ocupaciones humanas en el Pleistoceno inferior y medio de la Cuenca de Guadix-Baza. Junta de Andalucía, Consejería de Cultura, pp. 57e76. Duval, M., Falgu eres, C., Bahain, J.J., Grün, R., Shao, Q., Aubert, M., Toro-Moyano, I., 2012. On the limits of using combined U-series/ESR method to date fossil teeth from two Early Pleistocene archaeological sites of the Orce area (Guadix-Baza basin, Spain). Quat. Res. 77, 482e491. Espigares, 2019. The earliest cut marks of Europe: a discussion on hominin subsistence patterns in the Orce sites (Baza basin, SE Spain). Sci. Rep. 9, 15408. https://doi.org/10.1038/s41598-019-51957-5. Farjon, A., Horne, D., Parfitt, S.A., Buckland, P.I., Lewis, M.D., 2020. Early Pleistocene conifer macrofossils from Happisburgh, Norfolk, UK, and their environmental implications for early hominin occupation. Quat. Sci. Rev. 232, 106115. https:// doi.org/10.1016/j.quascirev.2019.106115. Fauquette, S., Suc, J.P., Guiot, J., Diniz, F., Feddi, N., Zheng, Z., Bessais, E., Drivaliari, A., 1999. Climate and biomes in the west mediterranean area during the Pliocene. Palaeogeogr. Palaeoclimatol. Palaeoecol. 152, 15e36. Fielding, A.H., Bell, J.F., 1997. A review of methods for the assessment of prediction errors in conservation presence/absence models. Environ. Conserv. 24, 38e49. Fortelius, M., Solounias, N., 2000. Functional characterization of ungulate molars using the abrasion-attrition wear gradient: a new method for reconstructing palaeodiets. Am. Mus. Novit. 3301, 1e36. https://doi.org/10.1206/0003- 0082(2000)301<0001:FCOUMU>2.0.CO;2. Fortelius, M., Eronen, J.T., Jernvall, J., Liu, L., Pushkina, D., Rinne, J., Tesakov, A., Vislobokovo, I., Zhang, Z., Zhou, L., 2002. Fossil mammals resolve regional patterns of Eurasian climate change during 20 million years. Evol. Ecol. Res. 4, 1005e1016. Fortelius, M.,  Zliobait_ e, I., Kaya, F., Bibi, F., Bobe, R., Leakey, L., Werdelin, L., 2016. An ecometric analysis of the fossil mammal record of the Turkana basin. Phil. Trans. Biol. Sci. 371, 1e13. https://doi.org/10.1098/rstb.2015.0232. Garcia, T., F eraud, G., Falgu eres, C., de Lumley, H., Perrenoud, C., Lordkidpanidze, D., 2010. Earliest human remains in Eurasia: new 40Ar/39Ar dating of the Dmanisi hominid-bearing levels, Georgia. Quat. Geochronol. 5, 443e451. Gibert, J., Arribas, A., Ter an, J., Palomar, J., 1992. Contexto geol ogico del Barranco del Paso (Orce, Granada). In: Gibert, J. (Ed.), Presencia Humana en el Pleistoceno Inferior de Granada y Murcia Proyecto Orce-Cueva Victoria (1988-1992. Ayuntamiento de Orce, pp. 203e218. Gliozzi, E., Abbazzi, L., Argenti, P., Azzaroli, A., Caloi, L., Capasso Barbato, L., Di Stefano, G., Esu, D., Ficcarelli, G., Girotti, O., Kotsakis, T., Masini, F., Mazza, P., Mezzabotta, C., Palombo, M.R., Petronio, C., Rook, L., Sala, B., Sardella, R., Zanalda, E., Torre, D., 1997. Biochronology of selected mammals, molluscs and ostracods from the Middle Pliocene to the late Pleistocene in Italy. The state of the art. Rivista Italiana di Paleontologia Stratigrafica 103, 369e388. Guldemond, R., Purdon, A., van Aarde, R.J., 2017. Asystematic review of elephant impact across Africa. PloS One 12, e0178935. Hesla, B.I., Tieszen, H.L., Boutton, T.W., 1985. Seasonal water relations of savanna shrubs and grasses in Kenya, East Africa. J. Arid Environ. 8, 15e31. Huguet, R., Vallverdú, J., Rodríguez-  Alvarez, X.P., Terradillos-Bernal, M., Bargall o, A., Lombera-Hermida, A., Men endez, L., Modesto-Mata, M., Van der Made, J., Soto, M., Blain, H.-A., García, N., Cuenca-Besc os, G., G omez-Merino, G., P erez- Martínez, R., Exp osito, I., Allu e, E., Rofes, J., Burjachs, F., Canals, A., Benn asar, M., Nu~ nez-Lahuerta, C., Bermud ez del Castro, J.M., Carbonell, E., 2017. Level TE9c of Sima del Elefante (Sierra de Atapuerca, Spain): a comprehensive approach. Quat. Int. 433, 278e295. Janis, C.M., 1990. Correlation of cranial and dental variables with body size in ungulates and macropodoids. In: Damuth, J., MacFadden, B.J. (Eds.), Body Size in Mammalian Palaeobiology eEstimation and Biological Implications. Cambridge University Press, New York, pp. 255e299. Kujper, D.P.J., te Beest, M., Churski, M., Cromsigt, J.P.G.M., 2015. Bottom-up and topdown forces shaping wooded ecosystems: lessons from a cross-biome comparison. In: Hanley, T.C., La Pierre, K.J. (Eds.), Trophic Ecology: Bottom-Up and Top-Down Interactions across Aquatic and Terrestrial Systems. Ecological Reviews. Cambridge University Press, pp. 107e133. Lawing, A.M., Eronen, J.T., Blois, J.L., Graham, C.H., Polly, P.D., 2017. Community functional trait composition at the continental scale: the effects of nonecological processes. Ecography 40, 651e663. Levin, N.E., 2015. Environment and climate of early human evolution. Annual Review of Earth and Planetary Sciences 43, 405e429. Liu, L., Puolam€ aki, K., Eronen, J.T., Mirzaie Ataabadi, M., Hernesniemi, E., Fortelius, M., 2012. Dental functional traits of mammals resolve productivity in terrestrial ecosystems past and present. Proc. R. Soc. Lond. B Biol. Sci. 279, 2793e2799. Martínez, K., Garcia, J., Carbonell, E., Agustí, J., Bahain, J.-J., Blain, H.-A., Burjachs, F., C aceres, I., Duval, M., Falgu erez, C., G omez, M., Huguet, R., 2010. A new lower Pleistocene archeological site in Europe (Vallparadís, barcelona, Spain). Proceedings of the National Academy of Sciences USA 107, 5762e5767. Martínez-Navarro, B., 2004. Hippos, pigs, bovids, saber-toothed tigers, monkeys, and hominids: dispersals through the Levantine Corridor during Late Pliocene and Early Pleistocene times. In: Goren-Inbar, N., Speth, J.D. (Eds.), Human Palaeoecology in the Levantine Corridor. Oxbow Books, Oxford, pp. 37e52. Messager, E., Lordkidpanidze, D., Kvavadze, E., Ferring, C.R., Voinchet, P., 2010. Palaeoenvironmental reconstruction of Dmanisi site (Georgia) based on palaeobotanical data. Quat. Int. 223e224, 20e27. Nogueira, C., Bugalho, M.N., Pereira, J.S., Caldeira, M.C., 2017. Extended autumn drought, but not nitrogen deposition, affects the diversity and productivity of a Mediterranean grassland. Environ. Exp. Bot. 138, 99e108. Ochando, J., Carri on, J.S., Blasco, R., Fern andez, S., Amor os, G., Munuera, M., Sa~ nudo, P., Fern andez Peris, J., 2019. Silvicolous neanderthals in the far west: the mid-pleistocene palaeoecological sequence of bolomor Cave (Valencia, Spain). Quat. Sci. Rev. 217, 247e267. Oksanen, O.,  Zliobait_ e, I., Saarinen, J., Lawing, A.M., Fortelius, M., 2019. A Humboldtian approach to life and climate of the geological past: estimating palaeotemperature from dental traits of mammalian communities. J. Biogeogr. 1e17. https://doi.org/10.1111/jbi.13586,2019. NPP multi-biome: global primary production data initiative products, R2. Data set. In: Olson, R.J., Scurlock, J.M.O., Prince, S.D., Zheng, D.L., Johnson, K.R. (Eds.), 2013. from the Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/617. Available on-line. http://daac.ornl.gov. J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 17 Oms, O., Anad on, P., Agustí, J., Julìa, R., 2011. Geology and chronology of the continental Pleistocene archeological and palaeontological sites of the Orce area (Baza basin, Spain). Quat. Int. 243, 33e43. Palmqvist, P., 2002. On the community structure of the large mammals assemblage from Dmanisi (East Georgia, Caucasus). In: De Renzi, M., Alonso, M., Belinch on, M., Pe~ nalver, E., Montoya, P., M arquez-Aliaga, A. (Eds.), Current Topics on Taphonomy and Fossilization. Ajuntament de Valencia, pp. 151e160. Palmqvist, P., Gro€ ocke, D.R., Arribas, A., Fari~ na, R.A., 2003. Palaeoecological reconstruction of a Early Pleistocene large mammal community using biogeochemical (d13C, d15N, d18O Sr:Zn) and ecomorphological approaches. Palaeobiology 29, 205e229. Parfitt, S.A., Ashton, N., Lewis, S.G., Abel, R.L., Coope, G.R., Field, M.H., Gale, R., Hoare, P.G., Larkin, N.R., Lewis, M.D., Karloukovski, V., Maher, B.A., Peglar, S.M., Preece, R.C., Whittaker, J.E., Stringer, C.B., 2010. Early Pleistocene human occupation at the edge of the boreal zone in northwest Europe. Nature 466, 229e233. Patterson, D.B., Braun, D.R., Behrensmeyer, A.K., Lehmann, S.B., Merrit, S.R., Reeves, J.S., Wood, B.A., Bobe, R., 2017b. Landscape scale heterogeneity in the East Turkana ecosystem during the okote member. J. Hum. Evol 112, 148e161, 1.56e1.38 Ma. Patterson, D.B., Braun, D.R., Behrensmeyer, A.K., Merrit, S.,  Zliobait_ e, I., Reeves, J.S., Wood, B.A., Fortelius, M., Bobe, R., 2017a. Ecosystem evolution and hominin palaeobiology at East Turkana, northern Kenya between 2.0 and 1.4 Ma. Palaeogeogr. Palaeoclimatol. Palaeoecol. 481, 1e13. Peterson, E.C., Shen, C., Chen, C., Chen, W., Tank, Y., 2003. Taphonomy of an early Pleistocene archaeofauna from xiaochangliang, Nihewan basin, north China. In: Current Research in Chinese Pleistocene Archaeology, vol. 1179. Bar International Series, Oxford, pp. 83e98. Pi~ nero, P., Agustí, J., Oms, O., Blain, H.-A., Laplana, C., Ros-Montoya, S., Martínez- Navarro, B., 2017. Rodents from Baza-1 (Guadix-Baza Basin, southeast Spain): filling the gap of the early Pliocene succession in the Betics. Journal of Vertebrate Paleontology 37, e1338294. https://doi.org/10.1080/ 02724634.2017.1338294. Qu ezel, P., M edail, F., 2003. Que faut-il entendre par "for^ ets m editerran eennes"? For^ et m editerran eenne XXIV, 11e31. Rodríquez, J., Mateos, A., Martín-Gonz ales, J.A., Rodríguez-G omez, G., 2015. How rare was human presence in Europe during the Early Pleistocene? Quat. Int. 389, 119e130. Saarinen, J., 2014. Ecometrics of Large Herbivorous Land Mammals in Relation to Climatic and Environmental Changes during the Pleistocene. PhD thesis. Department of Geosciences and Geography, University of Helsinki, ISBN 978- 952-10-9468-2. Retrieved from. http://urn.fi/URN. Saarinen, J., Eronen, J., Fortelius, M., Sepp€ a, H., Lister, A.M., 2016. Patterns of diet and body mass of large ungulates from the Pleistocene of Western Europe, and their relation to vegetation. Palaeontol. Electron. 19, 1e58, 3.32A. palaeo-electronica. org/content/2016/1567-pleistocene-mammal-ecometrics. S anchez-Bandera, C., Oms, O., Blain, H.-A., Lozano-Fern andez, I., Bispal-Chinesta, J.F., Agustí, J., Saarinen, J., Fortelius, M., Titton, S., Serrano-Ramos, A., Luz on, C., Solano-García, J., Barsky, D., Jim enez-Arenas, J.M., 2020. New stratigraphically constrained palaeoenvironmental reconstructions for the first human settlement in western Europe: the early Pleistocene herpetofaunal assemblages from Barranco Le on and Fuente Nueva 3 (Granada, SE Spain). Quat. Sci. Rev. 243, 106466. Scott, K.M., 1990. Postcranial dimensions of ungulates as predictors of body mass. In: Damuth, J., MacFadden, B.J. (Eds.), Body Size in Mammalian Palaeobiology e Estimation and Biological Implications. Cambridge University Press, New York, pp. 301e335. Scott, G.R., Gibert, L., 2009. The oldest hand-axes in Europe. Nature 461, 82e85. Suc, J.-P., Popescu, S.-M., 2005. Pollen records and climatic cycles in the North Mediterranean region since 2.7 Ma. In: Head, M.J., Gibbard, P.L. (Eds.), EarlyeMiddle Pleistocene Transitions: the LandeOcean Evidence, vol. 247. Geological Society, London, Special Publications, pp. 47e158. Teague, R.L., Potts, R., 2007. Faunal and behavioral context of the earliest Pleistocene Homo in East Asia. Am. J. Phys. Anthropol. 44, 230. Titton, S., Barsky, D., Bargall o, A., Serrano-Ramos, A., Verg es, J.M., Toro-Moyano, I., Sala-Ramos, R., García Solano, J., Jim enez-Arenas, J.M., 2020. Subspheroids in the lithic assemblage of Barranco Le on (Spain): Recognizing the late Oldowan in Europe. PLoS ONE 15, 1e41. https://doi.org/10.1371/journal.pone.0228290 e0228290. Titton, S., Oms, O., Barsky, D., Bargall o, A., Serrano-Ramos, A., García-Solano, J., S anchez-Bandera, C., Yravedra, J., Blain, H.-A., Toro-Moyano, I., Jim enez- Arenas, J.M., Sala-Ramos, R., 2021. Oldowan stone knapping on a raw material reservoir deposit 1.4 million years ago at Barranco Le on (Orce, Spain). Archaeological and Anthropological Sciences 13 (108). https://doi.org/10.1007/s12520- 021-01353-w. Toro-Moyano, I., Martínez-Navarro, B., Agustí, J., Souday, C., Bermúdez de Castro, J.M., Martin on-Torres, M., Palmqvist, P., 2013. The oldest human fossil in Europe, from Orce (Spain). J. Hum. Evol. 65, 1e9.  Zliobait_ e, I., Rinne, J., Toth, A., Mechenich, M., Liu, L.P., Behrensmeyer, A.K., Fortelius, M., 2016. Herbivore teeth predict climatic limits in Kenyan ecosystems. Proc. Natl. Acad. Sci. U.S.A. 113, 12751e12756.  Zliobait_ e, I., Tang, H., Saarinen, J., Fortelius, M., Rinne, J., Rannikko, J., 2018. Dental ecometrics of tropical Africa: linking vegetation types and communities of large plant-eating mammals. Evol. Ecol. Res. 19, 127e147. J. Saarinen, O. Oksanen, I.  Zliobait_ e et al. Quaternary Science Reviews 268 (2021) 107132 18