On the chronological structure of the solutrean in Southern Iberia

The Solutrean techno-complex has gained particular significance over time for representing a clear demographic and techno-typological deviation from the developments occurred during the course of the Upper Paleolithic in Western Europe. Some of Solutrean's most relevant features are the diversity and techno-typological characteristics of the lithic armatures. These have been recurrently used as pivotal elements in numerous Solutrean-related debates, including the chronological organization of the techno-complex across Iberia and Southwestern France. In Southern Iberia, patterns of presence and/or absence of specific point types in stratified sequences tend to validate the classical ordering of the techno-complex into Lower, Middle and Upper phases, although some evidence, namely radiocarbon determinations, have not always been corroborative. Here we present the first comprehensive analysis of the currently available radiocarbon data for the Solutrean in Southern Iberia. We use a Bayesian statistical approach from 13 stratified sequences to compare the duration, and the start and end moments of each classic Solutrean phase across sites. We conclude that, based on the current data, the traditional organization of the Solutrean cannot be unquestionably confirmed for Southern Iberia, calling into doubt the status of the classically defined type-fossils as precise temporal markers.Fundacao para a Ciencia e Tecnologia [PTDC/HAH/64184/2006, PTDC/HIS-ARQ/117540/2010, SFRH/BD/65527/2009, SFRH/BPD/96277/2013]; National Geographic Society [8045-06]; Wenner-Gren Foundation for Anthropological Research [8290

Palaeodemographic modelling supports a population bottleneck during the Pleistocene-Holocene transition in Iberia

Demographic change lies at the core of debates on genetic inheritance and resilience to climate change of prehistoric hunter-gatherers. Here we analyze the radiocarbon record of Iberia to reconstruct long-term changes in population levels and test different models of demographic growth during the Last Glacial-Interglacial transition. Our best fitting demographic model is composed of three phases. First, we document a regime of exponential population increase during the Late Glacial warming period (c.16.6-12.9 kya). Second, we identify a phase of sustained population contraction and stagnation, beginning with the cold episode of the Younger Dryas and continuing through the first half of the Early Holocene (12.9-10.2 kya). Finally, we report a third phase of density-dependent logistic growth (10.2-8 kya), with rapid population increase followed by stabilization. Our results support a population bottleneck hypothesis during the Last Glacial-Interglacial transition, providing a demographic context to interpret major shifts of prehistoric genetic groups in south-west Europe

Nanodiamond-rich layer across three continents consistent with major cosmic impact at 12,800 cal BP

A major cosmic-impact event has been proposed at the onset of the Younger Dryas (YD) cooling episode at ≈12,800 ± 150 years before present, forming the YD Boundary (YDB) layer, distributed over 150 million km2 on four continents. In 24 dated stratigraphic sections in 10 countries of the Northern Hemisphere, the YDB layer contains a clearly defined abundance peak in nanodiamonds (NDs), a major cosmic-impact proxy. Observed ND polytypes include cubic diamonds, lonsdaleite-like crystals, and diamond-like carbon nanoparticles, called n-diamond and i-carbon. The ND abundances in bulk YDB sediments ranged up to ≈500 ppb (mean: 200 ppb) and that in carbon spherules up to ≈3700 ppb (mean: ≈750 ppb); 138 of 205 sediment samples (67%) contained no detectable NDs. Isotopic evidence indicates that YDB NDs were produced from terrestrial carbon, as with other impact diamonds, and were not derived from the impactor itself. The YDB layer is also marked by abundance peaks in other impact-related proxies, including cosmic-impact spherules, carbon spherules (some containing NDs), iridium, osmium, platinum, charcoal, aciniform carbon (soot), and high-temperature melt-glass. This contribution reviews the debate about the presence, abundance, and origin of the concentration peak in YDB NDs.We describe an updated protocol for the extraction and concentration of NDs from sediment, carbon spherules, and ice, and we describe the basis for identification and classification of YDB ND polytypes, using nine analytical approaches. The large body of evidence now obtained about YDB NDs is strongly consistent with an origin by cosmic impact at ≈12,800 cal BP and is inconsistent with formation of YDB NDs by natural terrestrial processes, including wildfires, anthropogenesis, and/or influx of cosmic dust

Late Pleistocene leopards as a bone accumulator: taphonomic results from S’Espasa cave and other Iberian key sites

The Pleistocene faunal accumulations documented in caves have commonly been attributed to the activity of humans or carnivores. According to the palaeontological and archaeological literature, cave hyena (Crocuta spelaea) was the main known bone accumulator in karstic environments. However, in recent times, the role of leopards as bone accumulators has been revealed, and recent research has identified this behaviour in the Iberian Pleistocene. Moreover, there are other caves where leopard could have been claimed as an accumulator such as S’Espasa. In this work we present its taphonomic study. This cave was compared with the actualistic studies of leopards. Besides, the site of S’Espasa was compared with the other leopard dens in the Iberian Peninsula. These sites present faunal assemblages composed mainly by leopard (Panthera pardus) and Iberian wild goat (Capra pyrenaica), the bones of this ungulate present a similar pattern of bone modification by carnivores, skeletal survival rate, and bone breakage. These features indicate that goats could have been accumulated by leopards. With the data from this work and the previous ones, we try to establish a pattern that will help in the future to identify other accumulations created by this big cat.Fil: Sauqué Latas, Víctor. Universidad de Zaragoza; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; ArgentinaFil: Sanchis, Alfred. Museu de Prehistòria de València; EspañaFil: Madurell Malapeira, Joan. Universitat Autònoma de Barcelona; Españ