La inversión Matuyama-Brunhes en la secuencia de terrazas del río Jarama entre Velilla de San Antonio y Altos de la Mejorada, al SE de Madrid (España)

Al Este de la ciudad de Madrid, en el valle del río Jarama y entre Mejorada del Campo y Velilla de San Antonio se han estudiado las propiedades paleomagnéticas de una secuencia de terrazas comprendidas entre El Rasillo y Altos de la Mejorada, a lo largo de la autopista M-203 de reciente construcción. La cartografía geomorfológica realizada permitió separar además de la llanura aluvial a +4-5 m, terrazas a +20 m, +30-35 m, +60-65 m, +85-90 m, +105-110 m y +125-130 m. De ellas se muestrearon 5 niveles, a excepción de la de +20 m, en taludes frescos de la autovía que permiten situar a las terrazas con altitudes relativas igual o mayores a +60-65 m en el Chron Matuyama, mientras que las terrazas a +20 m y +30-35 m pertenecerían al Chron Brunhes (< 0.780 Ma). Dataciones por ESR en terrazas del valle del río Arlanzón en Burgos (Moreno et al., 2012), sugieren que en el valle del Jarama la inversión Matuyama-Brunhes podría establecerse entre el final de la sedimentación de la terraza a +60-65 m y el encajamiento de la terraza a +50-55 m subsiguiente, representada aguas arriba de Mejorada del Campo, en Marchamalo (Pérez-González, 1994)

Earliest Porotic Hyperostosis on a 1.5-Million-year-old Hominin, olduvai gorge, Tanzania.

Meat-eating was an important factor affecting early hominin brain expansion, social organization and geographic movement. Stone tool butchery marks on ungulate fossils in several African archaeological assemblages demonstrate a significant level of carnivory by Pleistocene hominins, but the discovery at Olduvai Gorge of a child's pathological cranial fragments indicates that some hominins probably experienced scarcity of animal foods during various stages of their life histories. The child's parietal fragments, excavated from 1.5-million-year-old sediments, show porotic hyperostosis, a pathology associated with anemia. Nutritional deficiencies, including anemia, are most common at weaning, when children lose passive immunity received through their mothers' milk. Our results suggest, alternatively, that (1) the developmentally disruptive potential of weaning reached far beyond sedentary Holocene food-producing societies and into the early Pleistocene, or that (2) a hominin mother's meat-deficient diet negatively altered the nutritional content of her breast milk to the extent that her nursing child ultimately died from malnourishment. Either way, this discovery highlights that by at least 1.5 million years ago early human physiology was already adapted to a diet that included the regular consumption of meat

Reassessing the role of carnivores in the formation of FLK North 3 (Olduvai Gorge, Tanzania): A pilot taphonomic analysis using Artificial Intelligence tools

FLK North (FLK N) (Bed I, Olduvai Gorge, Tanzania) is one of the best examples of a palimpsest where felids, hyenids and hominins made use of the same space without or with minimal interaction between hominins and the other two carnivores. Felids have been interpreted as the main accumulators and carcass consumers followed by frequent hyenid intervention. The presence of hominins at this site has been documented through the discovery of stone tools. Here, we test previous taphonomic interpretations of this site through the application of Artificial Intelligence (AI) tools (computer vision applied to bidimensional images of tooth pits) to taxonomically discriminate carnivore-made tooth marks. The bones we analyzed constitute a small sample, being a preliminary study of bone surface modifications (BSM) through the application of AI to a sample of the FLK N archaeofaunal assemblage (mostly to Level 3 fossils), pending access to the larger excavated collections. The results obtained in the present study show that the marks analyzed have been generated both by hyenids and felids. The slight predominance of hyena tooth marks is expected, since the bone sample used is dominated by long limb bones, and hyenas are the most likely agent causing long bone breakage, although felids also break bones of carcasses smaller than 150 kg as documented in the site. Felid impact, in at least three cases, is documented with tooth marks imprinted by felids and hyenas occurring on the same specimens. Felid-hyenid interaction is, thus, documented though the deep learning methods applied. The limited number of specimens where both agents are documented suggest that both hyenids and felids were independently breaking a substantial part of the bones at FLK N. This preliminarily modifies previous interpretations that attributed most long bone fragmentation exclusively to hyenas

Flint and Quartzite: Distinguishing Raw Material Through Bone Cut Marks

Since the 1980s, several experimental analyses have been able to differentiate some lithic tool types and some of their raw materials according to the morphology of cut marks imprinted by such tools when used for butchering activities. Thus, metal tool use has been differentiated in contexts with an abundance of lithic tools, or even the use of hand axes has been documented in carcass processing, in contrast with simple unretouched or retouched flakes. As important as this information is, there are still other important aspects to be analysed. Can cut marks produced with different lithic raw material types be differentiated? Can cut marks made with different types of the same raw material type be characterized and differentiated? The objective of this study is to evaluate if cut marks resulting from the use of different flints and different quartzites are distinguishable from each other. In the present work, an experimental analysis of hundreds of cut marks produced by five types of flint and five varieties of quartzite was carried out. Microphotogrammetry and geometric–morphometric techniques were applied to analyse these cut marks. The results show that flint cut marks and quartzite cut marks can be characterized at the assemblage level. Different types of flint produced cut marks that were not significantly different from each other. Cut marks made with Olduvai Gorge quartzite were significantly different from those produced with a set comprising several other types of quartzites. Crystal size, which is larger in Olduvai Gorge quartzites (0.5 mm) than Spanish quartzites (177–250 μm), is discussed as being the main reason for these statistically significant differences. This documented intra-sample and inter-sample variance does not hinder the resolution of the approach to differentiate between these two generic raw material types and opens the door for the application of this method in archaeological contexts

Late Middle Pleistocene malacofauna of the Acheulean site of Valdocarros II, Jarama river valley, Madrid, Spain

ing to its geographical position relative to northwestern Europe, the Iberian Peninsula was a refuge for many species during periods of harsh environmental conditions in the Quaternary. Despite this, the Pleistocene history of non-marine molluscs in Spain has been scarcely addressed. In this study, we examine the malacofauna of Valdocarros II, a site within the Complex Terrace of Arganda in the Jarama river valley tributary of the Tagus River in central Spain. This large, minutely-excavated site consists of five flood sequences identified in five archaeological levels and has been dated to the late Middle Pleistocene (end MIS 8–beginning MIS 7). Specimens of twelve freshwater and eighteen land mollusc taxa were identified. The most abundant species observed was Xerotricha madritensis, a land snail endemic to the Iberian Peninsula that today inhabits exposed surfaces with scarce plant cover. The most abundant freshwater species found was Anisus spirorbis, which currently thrives in tributaries of the Jarama River. This malacofauna assemblage features different ecological components, though dry, open-ground terrestrial species predominate. A correspondence analysis of the most frequently appearing land animals and the archaeological levels revealed a slight separation of level 2 from the other levels, indicative of its mesophilous character. However, few differences among these levels were identified in three correspondence analyses performed on the land or freshwater species datasets. Our observations of the malacofauna assemblage of Valdocarros II indicate a site characterized by a temperate climate and open areas with riverside vegetation. Furthermore, we propose the assignment of this site to an interstadial given the observed malacofauna of the five levels

Reconstitution paléoenvironnementale et paléoclimatique du Pléistocène supérieur ancien (MIS 5a) dans le Centre de l’Espagne : les petits vertébrés (Amphibia, Reptilia & Mammalia) des gisements de Hat et Preresa (sud-est de Madrid

Les gisements archeologiques de Hat et Preresa sont situes respectivement dans les vallees des rivieres Jarama et Manzanares, a environ 6 km l’un de l’autre et a 18 km au sud-est de Madrid. Ils correspondent a des depots de plaines d’inondation ayant conserve les restes d’activites ponctuelles de groupes de neanderthaliens notamment le depecage de carcasses de grands mammiferes il y a environ 80 000 ans. Les assemblages de petits vertebres recuperes lors des campagnes de fouilles de 2001 a Hat et de 2003 a 2005 a Preresa sont composes par des amphibiens (Pelobates cultripes, Pelodytes sp., Bufo bufo, Bufo calamita, Hyla sp. et Pelophylax perezi), des reptiles (Testudinoidea indet., Blanus sp., Timon lepidus, Psammodromus cf. algirus, Natrix maura, Coronella sp. et Vipera latastei) et des petits mammiferes (Erinaceus europaeus, Crocidura russula, Rhinolophus ferrumequinum, Eliomys quercinus quercinus, Apodemus sp., Cricetulus (Allocricetus) bursae, Arvicola aff. sapidus, Microtus cabrerae, Microtus duodecimcostatus et Oryctolagus cuniculus). Ces deux gisements, d’âge plus ou moins similaire, ont permis de mettre en evidence a la fin du dernier interglaciaire (MIS 5a) et dans le Centre de la peninsule Iberique l’existence d’un climat de type mediterraneen (quatre mois de secheresse durant l’ete et le debut de l’automne) comparable, voire plus chaud que l’actuel avec des precipitations plus abondantes durant les mois d’hiver et de printemps, et d’une continentalite moins prononcee, comme consequence d’une hausse des temperatures hivernales. Ce climat semble avoir ete propice, a l’existence de zones boisees humides, au moins en bordure des fleuves et d’espaces steppiques ou de prairies seches avec arbustes sur les plateaux environnants

Non-funerary Bell Beakers in the province of Toledo: the site of Las Vegas (the valley of Huecas once again).

Presentamos los resultados de los sondeos del yacimiento de Las Vegas, Huecas (Toledo). Se trata de un área abierta, junto al arroyo y al pie de la necrópolis de Valle de las Higueras. Un fuerte depósito de coluvión sepulta el yacimiento. Sin evidencias en superficie, su detección se realizó mediante prospección geofísica. Carece de estructuras y está formado por un único estrato, un depósito secundario que contiene campaniforme Ciempozuelos y metal, con una fecha C14 de la 2ª mitad del III milenio a.C. La cerámica es el material más abundante. Su estudio macroscópico y mediante fluorescencia de rayos X (FRX) avala su producción local, la rápida formación del depósito y su larga exposición en superficie. Planteamos que el depósito procede de la limpieza y mantenimiento de un área de ocupación anexa. El patrón de poblamiento parece seguir las tierras bajas del valle con ocupaciones cuyas producciones cerámicas difieren de las de los contextos funerarios.This article presents the latest results of the excavations at the site of Las Vegas in Huecas (Toledo). The site is located in an open area, near a stream and at the foot of the Valle de las Higueras necropolis. It is buried by a considerable colluvial deposition and was detected by geophysical survey. The site lacks structures and is made up of a single archaeological layer: it is a secondary deposit, containing Bell Beaker pottery and metal. A 14C sample has dated it to the second half of the 3rd millennium BC. Ceramics are the most abundant remain from this deposit. Macroscopic and X‑ray Fluorescence (FRX) analysis of the ceramics indicates a local production, the fast formation of this deposit, and its long‑term exposure on the surface. We suggest that it was formed by cleaning and maintenance activities carried out in a nearby occupational area. We suggest that settlement occurred in the valley bottom, with occupations whose ceramic productions differ from the ones found in funerary contexts