José-Antonio López-Sáez

Bio: José-Antonio López-Sáez is an academic researcher from Spanish National Research Council. The author has contributed to research in topics: Radiocarbon dating & Peninsula. The author has an hindex of 4, co-authored 5 publications receiving 83 citations.

A context for the last Neandertals of interior Iberia: Los Casares cave revisited

Abstract: Introduction and objectives Although the Iberian Peninsula is a key area for understanding the Middle to Upper Paleolithic transition and the demise of the Neandertals, valuable evidence for these debates remains scarce and problematic in its interior regions. Sparse data supporting a late Neandertal persistence in the Iberian interior have been recently refuted and hence new evidence is needed to build new models on the timing and causes of Neandertal disappearance in inland Iberia and the whole peninsula. In this study we provide new evidence from Los Casares, a cave located in the highlands of the Spanish Meseta, where a Neandertal-associated Middle Paleolithic site was discovered and first excavated in the 1960’s. Our main objective is twofold: (1) provide an updated geoarcheological, paleoenvironmental and chronological framework for this site, and (2) discuss obtained results in the context of the time and nature of the last Neandertal presence in Iberia. Methods We conducted new fieldwork in an interior chamber of Los Casares cave named ‘Seno A’. Our methods included micromorphology, sedimentology, radiocarbon dating, Uranium/Thorium dating, palinology, microfaunal analysis, anthracology, phytolith analysis, archeozoology and lithic technology. Here we present results on site formation processes, paleoenvironment and the chronological setting of the Neandertal occupation at Los Casares cave-Seno A. Results and discussion The sediment sequence reveals a mostly in situ archeological deposit containing evidence of both Neandertal activity and carnivore action in level c, dated to 44,899–42,175 calendar years ago. This occupation occurred during a warm and humid interval of Marine Isotopic Stage 3, probably correlating with Greenland Interstadial 11, representing one of the latest occurrences of Neandertals in the Iberian interior. However, overlying layer b records a deterioration of local environments, thus providing a plausible explanation for the abandonment of the site, and perhaps for the total disappearance of Neandertals of the highlands of inland Iberia during subsequent Greenland Stadials 11 or 10, or even Heinrich Stadial 4. Since layer b provided very few signs of human activity and no reliable chronometric results, and given the scarce chronostratigrapic evidence recorded so far for this period in interior Iberia, this can only be taken as a working hypothesis to be tested with future research. Meanwhile, 42,000 calendar years ago remains the most plausible date for the abandonment of interior Iberia by Neandertals, possibly due to climate deterioration. Currently, a later survival of this human species in Iberia is limited to the southern coasts.

First modern human settlement recorded in the Iberian hinterland occurred during Heinrich Stadial 2 within harsh environmental conditions.

Abstract: As the south-westernmost region of Europe, the Iberian Peninsula stands as a key area for understanding the process of modern human dispersal into Eurasia. However, the precise timing, ecological setting and cultural context of this process remains controversial concerning its spatiotemporal distribution within the different regions of the peninsula. While traditional models assumed that the whole Iberian hinterland was avoided by modern humans due to ecological factors until the retreat of the Last Glacial Maximum, recent research has demonstrated that hunter-gatherers entered the Iberian interior at least during Solutrean times. We provide a multi-proxy geoarchaeological, chronometric and paleoecological study on human–environment interactions based on the key site of Pena Capon (Guadalajara, Spain). Results show (1) that this site hosts the oldest modern human presence recorded to date in central Iberia, associated to pre-Solutrean cultural traditions around 26,000 years ago, and (2) that this presence occurred during Heinrich Stadial 2 within harsh environmental conditions. These findings demonstrate that this area of the Iberian hinterland was recurrently occupied regardless of climate and environmental variability, thus challenging the widely accepted hypothesis that ecological risk hampered the human settlement of the Iberian interior highlands since the first arrival of modern humans to Southwest Europe.

Taphonomic and Ecologic Information Form Bone Weathering

Abstract: Bones of recent mammals in the Amboseli Basin, southern Kenya, exhibit distinctive weathering characteristics that can be related to the time since death and to the local conditions of temperature, humidity and soil chemistry. A categorization of weathering characteristics into six stages, recognizable on descriptive criteria, provides a basis for investigation of weathering rates and processes. The time necessary to achieve each successive weathering stage has been calibrated using known-age carcasses. Most bones decompose beyond recognition in 10 to 15 yr. Bones of animals under 100 kg and juveniles appear to weather more rapidly than bones of large animals or adults. Small-scale rather than widespread environmental factors seem to have greatest influence on weathering characteristics and rates. Bone weathering is potentially valuable as evidence for the period of time represented in recent or fossil bone assemblages, in- cluding those on archeological sites, and may also be an important tool in censusing populations of animals in modern ecosystems.

Chronostratigraphy of the Middle-to-Upper Paleolithic Transition in the Iberian Peninsula : Euskadi / Joao Zilhao.

Abstract: The complex environmental history of Isotope Stage Three carries the implication that cave and rockshelter sites containing deposits from the time of the Middle-to-Upper Paleolithic transition must have been significantly affected by syn- and post-depositional disturbance processes. A detailed taphonomic critique of the stratigraphic successions, of the integrity of archeological levels, of the composition of industrial assemblages, and of the associations between samples selected for dating and the events or processes they are supposed to date is therefore an absolute requirement in assessing the tempo and mode of that transition. Once the evidence yielded by the key Iberian sites is passed through such a taphonomic filter, and the chronometric results obtained by different dating methods are reduced to a single, calendar timescale, and taken with due consideration of the inherent level of statistical uncertainty, a rather clear picture emerges. Regions located north of the Ebro divide follow the general European pattern, where the transition is a two step process featuring, first, the emergence out of local Middle Paleolithic roots of different Neandertal-associated early Upper Paleolithic technocomplexes (in the case of northern Iberia, the Châtelperronian, known from Morin, in the west, to l’Arbreda, in the east) and, second, the replacement of the latter by the Protoaurignacian, which takes place ca. 42 ka BP (in calendar years), i.e., at about the time when modern human populations are first recorded in Europe. South of the Ebro divide, a Neandertal-associated Middle Paleolithic survives for several millennia more, and is eventually replaced by the Evolved Aurignacian (Aurignacian II), an event that, from Alicante, in the east, to Portugal, in the west, takes place no later than ca.35 ka BP (in calendar years). The paleoenvironmental record suggests that this delayed survival of Middle Paleolithic Neandertals in southwestern Iberia is related to a prolonged period of ameliorated climatic conditions that, at least in littoral areas, may have favored the expansion of woodland landscapes.

Erratum: A late Neanderthal associated with Upper Palaeolithic artefacts

Abstract: Nature 381, 224–226 (1996) One of the important morphometric variables assessed in the comparisons between the bony labyrinths of Neanderthals and modern humans is the sagittal labyrinthine index. This index expresses what percentage of the posterior semicircular canal is situated inferiorly to the plane of the lateral semicircular canal.

Oldest Evidence of Toolmaking Hominins in a Grassland- Dominated Ecosystem

Abstract: Background: Major biological and cultural innovations in late Pliocene hominin evolution are frequently linked to the spread or fluctuating presence of C4 grass in African ecosystems. Whereas the deep sea record of global climatic change provides indirect evidence for an increase in C4 vegetation with a shift towards a cooler, drier and more variable global climatic regime beginning approximately 3 million years ago (Ma), evidence for grassland-dominated ecosystems in continental Africa and hominin activities within such ecosystems have been lacking. Methodology/Principal Findings: We report stable isotopic analyses of pedogenic carbonates and ungulate enamel, as well as faunal data from ,2.0 Ma archeological occurrences at Kanjera South, Kenya. These document repeated hominin activities within a grassland-dominated ecosystem. Conclusions/Significance: These data demonstrate what hitherto had been speculated based on indirect evidence: that grassland-dominated ecosystems did in fact exist during the Plio-Pleistocene, and that early Homo was active in open settings. Comparison with other Oldowan occurrences indicates that by 2.0 Ma hominins, almost certainly of the genus Homo, used a broad spectrum of habitats in East Africa, from open grassland to riparian forest. This strongly contrasts with the habitat usage of Australopithecus, and may signal an important shift in hominin landscape usage.