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Level TE9c of the Sima del Elefante site (Sierra de Atapuerca, Spain) is one of the oldest sites with evidence of human occupation in western Europe. We began excavating level TE9c in 2003, and the work there continues today. The studies of the archaeology, palaeontology and geology from this locality have provided an indispensable dataset with which to capture a picture in the scenario of the origin of humans in Europe. Based on these data, we raise and discuss several topics, such as the possible origin of the lineage of the first hominins that inhabited western Europe; their capacity to have active hunting or scavenging abilities; whether their subsistence strategies were successful; and what the environment and habitats where these hominin groups settled was like. The aim of this paper is to present the results and discussions obtained from the research team and to establish the primary features of early human occupations in southwestern Europe. Tentatively, we may conclude, based on the events recorded at TE9c, that the first humans were in the Iberian peninsula at around 1.2 Ma they used the caves of the Sierra de Atapuerca as shelters probably during their hunting activities; the cavities were surrounded by Mediterranean forest, rivers and water ponds, and varied habitats as suggested by the rich and diverse assemblage of fossils of vertebrates (fish, amphibians and reptiles, birds, large and small mammals); where humans possibly caught what they found in the surroundings., This research project was supported by MINECO projects (CGL2012-38434-C03-03, CGL2012-38434-C03-02, CGL2012-38434-C03-01, HAR 2012-032548/HIST, HAR2013-41197-P) and AGAUR project (2014SGR-899, 2014-SGR 901).

No ideal method can be used alone to provide an accurate and irrefutable chronology for dating European Early Pleistocene localities. The solution lies in the combination of different, but complementary, approaches for complementing their chronological framework. In that regard, the results of the present study show that biochronology may be a useful additional tool to further refine the chronology of these localities, by providing not only relative chronological information between the sites, but also giving some important indications about a younger or older Jaramillo age. Our study presents the revised faunal list of each Early Pleistocene levels from the localities of Gran Dolina (TD) and Sima del Elefante (TE), in Atapuerca. Both localities have very likely the richest associations of small mammal species in the Quaternary of Europe. Perhaps the most striking observation is the lack of similarities between the assemblages from each site, which can only be explained by a chronological gap between them. Although the Jaramillo subchron has not been directly identified at Atapuerca, the existing chronostratigraphical framework combined with similarities of the faunal assemblages between Gran Dolina and Vallparadis indicate with some confidence that Sima del Elefante levels are older than the Jaramillo subchron. Consequently, the Early Pleistocene levels of both Atapuerca sites TE and TD are the only sequence from Spain that allows the study of a continuous stratigraphic succession of the interval around the Jaramillo subchron in terrestrial sequences. The biostratigraphy of the Early Pleistocene from Europe, based mainly in the few isolated localities of the Olduvai–Jaramillo time interval, is reinforced by the faunal succession of the Atapuerca sites.

The cave of Askondo (Manaria, Bizkaia, Spain) is an archaeological site on the western flank of Asko Mount. Archaeological excavations in 2011 have provided a prehistoric and historic sequence from the Middle Palaeolithic to the Bronze Age. Approximately 3000 microvertebrate elements (including mammals, reptiles, and amphibians) were recovered, of which 387 were identified to the genus and/or species levels. The small mammal assemblage comprises at least 17 taxa: nine species of rodents (Glis glis, Apodemus sylvaticus-flavicollis, Arvicola amphibius, Microtus agrestis, Microtus arvalis, Microtus (Terricola) sp., Microtus oeconomus, Chionomys nivalis, and Clethrionomys glareolus), two insectivores (Sorex araneus-coronatus and Talpa sp.), three amphibians (Bufo calamita, Bufo bufo, and Rana temporaria-iberica), and three reptiles (Lacertidae indet., Anguis fragilis, and Colubridae indet.). This assemblage has enabled us to roughly reconstruct the environmental conditions that prevailed in the cave's surrounding area. It evolved from a landscape with considerable woodlands to an arid one, characteristic of cold conditions, at the beginning of the Upper Palaeolithic (ca. 35,300 cal BP). After a short episode of alternating woodland expansion and contraction, the woodlands expanded again at the end of the Solutrean (ca. 21,000 cal BP). Finally, at the top of the sequence, the climate began a warming trend that has led to its current landscape.

The cave of Santimamine (Kortezubi, Bizkaia, Spain), on the southern slopes of the Erenozar Mountain (Urdaibai biosphere reserve), is one of the most famous prehistoric localities of the Cantabrian range. Between 2004 and 2006, a test trench revealed a 6 m-deep stratigraphic sequence in the inner vestibule of the cave covering ∼20,000 years, from the latest Late Pleistocene (MIS 2) to the middle Holocene (MIS 1). It comprises six chrono-cultural units: lower, middle and upper Magdalenian, Azilian, Neolithic, and Chalcolithic/Bronze Age, plus seven lower purely palaeontological levels. More than 47,000 microvertebrate elements (including mammals, birds, reptiles, amphibians and fishes) were recovered, of which 1587 were identified to the genus and/or species levels. Of these, small mammals were used for paleoenvironmental reconstruction since they are very sensitive to climatic conditions and their distributions over time, measured in terms of relative abundance, serve as reliable proxies of habitat and climatic change. The reconstruction of Santimamine past environments based on small mammals roughly coincides with other proxies, such as the amphibian/reptile, large mammal/bird, palynological, and cryoclastic records on the local scale; other paleoenvironmental reconstructions from north Iberia on the regional scale; and the oxygen isotopic curve of an ice core from central Greenland on the global scale. All Magdalenian levels from Santimamine were deposited during the Oldest Dryas, a mostly cold and humid period including the Heinrich event 1. Small mammalian, palynological and cryoclastic evidence likely document the shift from the cold Younger Dryas to the beginning of the Holocene Climatic Optimum during Azilian times. The uppermost level, deposited during a moderate re-opening of the landscape at the Subboreal, slightly postdates the Holocene Cooling Event 3.

The Kiputz IX site records climatic variations during the Late Pleistocene since it represents a continuous time interval record (ca. 25–13 ka cal BP). Carbon and nitrogen stable isotopes from the bone collagen of herbivores ( Rangifer tarandus , Cervus elaphus , and Bison priscus ) were analysed to establish environmental and climatic conditions in the northern Iberian Peninsula. Faunal distribution over time represents a response to climatic variations, showing inverse patterns with reindeer and bison profusion during cold periods and red deer abundance during warmer times. The increase in reindeer δ 15 N values during stadial GS-2 appears to be greater in magnitude than in continental Europe and reflects drier, warmer climatic conditions. The δ 13 C values of red deer suggest more humid environmental conditions south of the Pyrenees. During interstadial GS-1 the climatic conditions of southern Pyrenees appear to be analogous to that of northern Pyrenees regions.

Acknowledgements go first of all to the Atapuerca Foundation, the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences and the MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences of Fudan University in collaboration with the Spanish Pavilion of the Shanghai Universal Expo 2010, which organized the Shanghai conference “First Human Settlements in Eurasia”. Over the last 20 years the Atapuerca excavation team has helped with the extraction of small mammals. The study and conservation of the fossils is supported by the University of Zaragoza, the Junta de Castilla y Leon, the MICINN-CGL2009-12703-C03-03project, the Fundacion Atapuerca, the Fundacion Duques de Soria, and Grupos Consolidados del Gobierno de Aragon. The SEM photographs were taken by us with the help of the SEM Service of the University of Zaragoza. J.R. (JCI-2010-06148) and J.M.L-G (JCI-2009-04026) have been supported by a postdoctoral grant from the Juan de la Cierva Subprogram, V.S.L (B019/09) and R.R.G (B113/2007) FPI program of the Gobierno de Aragon.

Thousands of fossils of small vertebrates are recorded in one of the most complete stratigraphic sequences of the continental European Pleistocene, in the Sierra de Atapuerca. This sequence, with a few interruptions, spans the last 1.5 million years. The stratigraphic series is recorded in six karstic cavities in the Sierra de Atapuerca. From the oldest record to the most modern one, these are the Sima del Elefante, Gran Dolina, Galeria–Zarpazos, Sima de los Huesos, El Portalon and El Mirador. The faunal successions of continental microvertebrates have made it possible to divide the Atapuerca sequence into 7 faunal units (Atapuerca Faunal Units, ATA FUs), which are based on the first and last local appearances of taxa (LO, HO). The Spanish Quaternary small vertebrate faunas are grouped into 5 distinct biozones, from the oldest to the most recent: Allophaiomys pliocaenicus , Allophaiomys lavocati , Allophaiomys chalinei , Iberomys brecciensis and Iberomys cabrerae . These are calibrated with radiometric and palaeomagnetic dating, allowing the proposal of a continental biochronological scale for the Pleistocene of the Iberian Peninsula.