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Bone diagenesis is a complex process that modifies bone components in response to burial conditions. These modifications help to understand deposit formation and classify fossils by stratigraphy. The combined techniques of X-ray diffraction with Rietveld refinement and infrared spectroscopy were used to study the bone diagenetic processes along the complete stratigraphic sequence of Galería site (Sierra de Atapuerca, Spain). Eleven chemometric indices considering the different bone components (phosphates, carbonates, organic phase), together with the apatite unit cell parameters and cell volume were evaluated by 9 machine learning algorithms for bone diagenesis/stratigraphic classification. The results showed differences along the stratigraphic sequence due to changes in the apatite structure chemistry (i.e., F− and OH−), producing a gradual shift of the unit cell volume (from 531.9 to 526.1 Å3) from GII to GIV associated with coupled dissolution–precipitation processes. Two diagenetic pathways are indicated: The lowest unit (GII) is characterized by leaching and carbonate loss in bone, suggesting an acidic and wet burial environment with the formation of authigenic phosphate minerals. The uppermost units (GIII-GIV) show bone apatite undergoing F− and CO3 incorporation, suggesting a slightly alkaline and drier environment. These differences enabled the development of classification models to understand deposit formation dynamics and also recontextualize dissociated fossil bones. [ABSTRACT FROM AUTHOR]

Here, we present a thorough taphonomic analysis of the 1.84 million-year-old site of Phillip Tobias Korongo (PTK), Bed I, Olduvai Gorge. PTK is one of the new archaeological sites documented on the FLK Zinj paleolandscape, in which FLK 22 level was deposited and covered by Tuff IC. Therefore, PTK is pene-contemporary with these sites: FLK Zinj, DS, AMK and AGS. The occurrence of these sites within a thin clay unit of ∼20 cm, occupying not only the same vertically discrete stratigraphic unit, but also the same paleosurface, with an exceptional preservation of the archaeological record in its primary depositional locus , constitutes a unique opportunity to explore early hominin behavioral diversity at the most limited geochronological scale possible. The Olduvai Bed I sites have been the core of behavioral modelling for the past half a century, and the newly discovered sites, excavated with 21st century technology, will increase significantly our understanding of early human adaptive patterns. Here, we present PTK as another assemblage where faunal resources were acquired by hominins prior to any carnivore, and where stone-tool assisted bulk defleshing was carried out. The abundance of juvenile individuals extends our understanding, as in Kanjera (Kenya), about the hunting skills of early Homo sensu lato. The increasing number of sites, where bulk defleshing of small and medium-sized carcasses took place is underscoring the importance of meat in the diets of some of the early hominins, and their patterned use of the space for food processing and consumption. The patterning emerging has a profound importance for the evolution of some of the features that have traditionally been used to identify the behavior of the genus Homo. • The new site of PTK, Bed I, Olduvai Gorge, Tanzania (c. 1.84 Ma) shows well-preserved evidence of hominin meat eating. • Machine learning methods are applied to discern the agent of bone breakage. • Butchery marks and machine learning provide information about past carnivore and hominin behavior. • The abundance of young individuals suggests that the hominins employed a selective hunting strategy. [ABSTRACT FROM AUTHOR]

One of the first steps to address palaeontological studies is the taxonomic identification of fossils according to their morphology. Geometric Morphometric techniques together with multivariate statistical analysis are known to be precise tools to achieve this goal. More recent alternative techniques such as Machine Learning are still rarely used in Palaeontology, although it has been shown in various examples that they can offer powerful alternative statistical approaches to analyse quantitative morphometric data. Here we show how Machine Learning applied to two-dimensional geometric morphometric data from the outline shape of the lower first molars of Mus spp. has proven useful to overcome taxonomic problems. We collated a photographic database of 303 lower first molars from modern populations of Mus musculus domesticus and Mus spretus from southwestern Europe and North Africa to compare the performance between classic multivariate statistics and Machine Learning algorithms in identifying the two species from their dental morphology. We also include Late Holocene Mus specimens from the Estrecho Cave (east-central Spain) to predict their specific status. Our results suggest that Machine Learning is more efficient than classical statistical analyses in taxonomic identification of Mus molars, reaching 100% of correct classification. The application of such techniques to fossil material showed that ensemble/stacking algorithms provided robust identification of both M. m. domesticus and M. spretus in the Estrecho Cave assemblage and confirmed that both species colonised the Iberian Peninsula at a time prior to the formation of the site. • Machine Learning combined with Geometric Morphometrics overcomes taxonomic issues. • Perfect classification of modern first lower molars of two Mus species was achieved. • Both Mus spretus and Mus musculus domesticus are identified in the Estrecho Cave. • Such identifications are in agreement with the available palaeobiogeographical data. [ABSTRACT FROM AUTHOR]

The interior of the Iberian Peninsula has few Middle Palaeolithic sites, especially when compared to other areas of the Mediterranean Basin and the northern Spanish region. Few in number too are the zooarchaeological and taphonomic studies that throw light on the relationships between Neanderthal groups, their environment, and the use they made of it. The present work examines, both zooarchaeologically and taphonomically, the faunal remains of levels F and D of the Navalmaíllo Rock Shelter (Pinilla del Valle, Madrid, Spain) - the largest collection of such remains ever studied from the Iberian interior. The results allow this site to be interpreted as a Neanderthal hunting camp where occupations were short-term. Neanderthal people were the main agents that accumulated the site's faunal remains - largely those of large bovids and to a lesser extent medium-sized cervids. The activity of carnivores was also identified, but these animals mostly left behind the remains of small prey or fed upon carcasses abandoned at the camp by human hunters. • Navalmaíllo Rock Shelter has been interpreted as a Neanderthal hunting camp. • All phases of butchery were identified, along with the extraction of bone marrow. • Bovines and cervids are the more common taxa in the assemblage. • There is a low degree of competition between hominins and large carnivores. • The faunal assemblage was little affected by post-depositional processes. [ABSTRACT FROM AUTHOR]

Neanderthals have been claimed to have had a selective adaptation to rugged, wooded landscapes that would have partially compensate their high basal metabolic rate and locomotor energetic costs through reducing search time and increasing diet breadth. The archaeological site of the Navalmaíllo rockshelter (Pinilla del Valle, Madrid), located in a mountain environment in central Iberian Peninsula, has been interpreted as a repeated short-term occupation hunting camp by Neanderthal groups, mainly focused on primary access to large bovids and cervids. Navalmaíllo rockshelter has also furnished fish, toads, frogs, tortoises, lizards and snakes remains. This association of amphibians and reptiles suggests a much warmer climate (+2.8 °C) for layer F than at present, with similar temperatures during the summer but higher temperatures throughout the remaining months. Rainfall was slightly more abundant (+180.6 mm) than today, with a more contrasted regime during the year, with rainier winters and drier summers. A two-month period of aridity is observed during summer, representing a similar duration to present-day climatic conditions. Reconstructed landscapes are mainly constituted by open areas with dry grassland and rocky or stony areas, evolving laterally to humid meadows, probably close to the aquatic and peri-aquatic areas, such as rivers or ponds with riverside vegetation. Woodland environments are also well represented around the site, with medium scrublands to forest formations. Fish complete this reconstruction by documenting the presence of a pre-mountain well-developed river system characterized by relatively cold, permanent, oxygen-rich, and running waters. Such reconstruction is in disagreement with previous pollen interpretation for Layer F that suggested a very open and cold environment. Our new interpretation suggests that the Neanderthal occupation of the Navalmaíllo rockshelter occurred during a somewhat temperate and humid period, probably within the later part of the Marine Isotope Stage 5, effectively favouring the presence of a high biodiversity around the site. • Neanderthal paleoecology from the Navalmaíllo rockshelter is revisited. • Amphibians and reptiles suggest warm and humid climate conditions. • Woodland environments are well represented around the site. • Such reconstruction is in disagreement with previous pollen-based interpretation. • Neanderthal occupation was favored by the presence of a high biodiversity. [ABSTRACT FROM AUTHOR]