The Acheulean of the Upper Guadiana River Basin (Central Spain). Morphostratigraphic Context and Chronology

In the upper basin of the Guadiana River, especially in the sectors drained by its right-bank tributaries, the Bullaque and Becea rivers, important concentrations of Acheulean and Mousterian industries can be found in a superficial position. These industries have provided series containing tens of thousands of pieces. Deposits in stratigraphic position have also been identified, related to the fluvial terraces of the Guadiana and Jabalón rivers and some tributaries. Within the sector studied, in the province of Ciudad Real, the position of these deposits is related to alluvial fans developed on the slopes of the immediate reliefs. These fans, mainly composed of Lower and Middle Ordovician quartzite gravel, were eroded in their distal positions by the Bullaque and Becea rivers, forming very low terraces on which large concentrations of Acheulean and Mousterian lithic industry can be found. El Sotillo, the only known stratigraphic site in the area, was excavated in 2017–2019 and consists of several levels with Mousterian and Acheulean industry. We present the technological characteristics of the main Acheulean assemblage recognised at this site, for which numerical dates have been obtained placing its chronology in the second half of the Middle Pleistocene. The location of these sites, in surficial position and El Sotillo, allows us to recognise a territorial space with specific geographic characteristics and a very significant human impact

The Middle to Late Pleistocene herpetofaunal assemblages from the Jarama and Manzanares valleys (Madrid, central Spain): an ecological synthesis

The successive fossil amphibian and reptile assemblages from the Middle to Late Pleistocene sites from the Manzanares and Jarama River Valleys (Madrid, central Spain) permitted the reconstruction of part of the climate instability with high-amplitude and rapid shifts of the last 450 ka and their associated landscapes: Áridos-1 (MIS11b), Valdocarros II (MIS8a/7e), Estanque de Tormentas de Butarque ETB-H02 (MIS7d or MIS6), PRERESA (MIS7/6 or MIS5a) and HAT (MIS5a). This work aims to present a regional synthesis of the palaeoclimatic and palaeoenvironmental data obtained from the herpetofaunal assemblages for these two valleys and their influence on the biodiversity during the Pleistocene. As a whole, these archaeo-paleontological localities document a total of 20 taxa (8 anurans and 12 reptiles) thus representing 76.9% of the modern authochtonous herpetofauna of the southeast of the Region of Madrid. Taking as a reference the modern situation in the area, the successive herpetofaunal assemblages permits a hypothetical landscape reconstruction where three different periods are represented with a glacial landscape (ETB-H02), a landscape of transition from cool to temperate climatic conditions (Valdocarros II), and an interglacial landscape (Áridos-1, HAT, PRERESA, and today). Environment is particularly open during dry periods, independently of if it is cold or warm. The main difference between an interglacial and a glacial period is the opposite representation of woodlands vs. moist environments: the last ones being more represented during cold periods than during warm periods. Finally, as documented by the succession from Valdocarros II, periods of transition between cold and warm climate are more forested but at the expense of humid meadows progressively. According to the relation between richness, biodiversity and climatic and environmental factors, a clear correlation appears between reptile richness and woodlands. In a similar way, mean annual precipitation (MAP) is revealed to be the most influent factor on reptile local diversity certainly because of its implications on vegetal cover extension and ecosystem productivity and resources. For amphibians the MAP does not influence dominancy but species richness: anuran richness being higher for lower MAP. Such an unusual pattern is certainly due to the fact that there are no strict forest-dweller anurans within the archaeological assemblages and that most of the anurans present in the sites are well adapted to arid conditions

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements