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Two cryptic species of mice coexist on Cyprus: the introduced house mouse and the endemic Cypriot mouse, which remained unnoticed until the beginning of the 21st century. Their trophic positions were investigated using isotopic ecology. The shape and biomechanics of the mandible provided a complementary insight into their respective diets. The Cypriot mouse exhibits generalist habits relying on various natural food resources, including invertebrates, while the house mouse exploits a broad spectrum of anthropic food resources. The Cypriot mouse has a large mandible optimized for chewing at the molars that facilitates consumption of large and hard food items presumably abundant in the natural vegetation of Cyprus. The small mandible size of the house mouse is compensated by a large masseter area and an optimization for incisor biting, making it an all-around tool for foraging on diverse non-natural items. This fine-tuning of generalist feeding behavior ensures efficient niche partitioning between the two species on Cyprus. [ABSTRACT FROM AUTHOR]

Over the last millennium, the town of Aghmat (Morocco) has undergone major socio-economic changes, raising the question of how these transformations have affected the development of agricultural systems and exploited landscapes over time. This preliminary pilot study brings together for the first time carpological, anthracological, and isotopic results from the Aghmat archaeological program that show a certain stability for staple productions (cereals, fruit) over the last millennium, and the exploitation of various landscapes. A shift appears to occur during the late Middle Ages, potentially due to more favorable conditions, with a specialization in olive cultivation as early as the fourteenth century, and significant deforestation following this olive growing boom. During the modern period, the importance of olive cultivation is confirmed, whether or not in conjunction with a decline in water availability and what appears to be irreversible deforestation. [ABSTRACT FROM AUTHOR]

Dinosaur eggshell fragments attributed to the oofamilies Spheroolithidae and Prismatoolithidae and recovered from the latest Cretaceous Kakanaut Formation of North-eastern Russia (Chukotka) constitute one of the northernmost records of dinosaur reproductive behaviors. The high palaeolatitude of the locality (~75° N), as well as the cool near-polar climate, where summer temperatures only averaged 20 °C during the warmest month, dark near-freezing winters and egg incubation that could have lasted several months, raise questions about dinosaur reproductive strategies, particularly in terms of the timing of egg laying. In order to investigate seasonal aspects of Kakanaut dinosaur reproductions, carbonate from eggshell fragments have been analyzed for their oxygen and carbon isotope compositions, along with the oxygen and carbon isotope compositions of apatite phosphate and structural carbonate of associated theropod, hadrosaur and ankylosaur teeth as well as lepisosteid fish scales. Stable oxygen and carbon isotope compositions of eggshells from the Kakanaut Formation together with those of associated adult dinosaur teeth and fish scales reveal differences in mineralization timing between eggshells and teeth and show that eggs were laid at the very beginning of spring when snowmelt drained from nearby highlands. We propose that Kakanaut dinosaurs laid their eggs at the very beginning of spring in order to accommodate an incubation period that lasted several months. This timing would also benefit from mild temperatures and increasing food availability when the eggs hatch, allowing the hatchlings to grow large enough to survive the next winter or perhaps follow adult animals in their migration southwards. [ABSTRACT FROM AUTHOR]

This study investigates the seasonality of the mercury (Hg) concentration of olive tree foliage, an iconic tree of the Mediterranean basin. Hg concentrations of foliage, stems, soil surface, and litter were analyzed on a monthly basis in ancient olive trees growing in two groves in Lebanon, Bchaaleh and Kawkaba (1300 and 672 m a.s.l. respectively). A significantly lower concentration was registered in stems (∼7 –9 ng g -1) in comparison to foliage (∼35 –48 ng g -1) in both sites, with the highest foliage Hg concentration in late winter–early spring and the lowest in summer. It is noteworthy that olive fruits also have low Hg concentrations (∼7 –11 ng g -1). The soil has the highest Hg content (∼62 –129 ng g -1) likely inherited through the cumulated litter biomass (∼63 –76 ng g -1). A good covariation observed between our foliage Hg time series analysis and those of atmospheric Hg concentrations available for southern Italy in the western Mediterranean basin confirms that mercury pollution can be studied through olive trees. Spring sampling is recommended if the objective is to assess the trees' susceptibility to Hg uptake. Our study draws an adequate baseline for the eastern Mediterranean and the region with similar climatic inventories on Hg vegetation uptake, in addition to being a baseline to new studies on olive trees in the Mediterranean to reconstruct regional Hg pollution concentrations in the past and present. [ABSTRACT FROM AUTHOR]

Ribemont‐sur‐Ancre, France, is the biggest excavated human skeletal assemblage of Northern Gaul. It is interpreted as a post‐battle deposit constructed to celebrate war. However, the chronology of the site, its organization and the origin of the buried warriors are still poorly understood. These problems are studied by a multi‐proxy approach, based on radiocarbon dating, stable and radiogenic isotope analysis of bone remains from three structures within the site. A total of 47 human and 12 animal bone samples were analyzed for their oxygen isotope composition of bone bioapatite (δ18Op), carbon and nitrogen isotope compositions of bone collagen (δ13Ccoll and δ15Ncoll). Subsamples of 17 bone collagen and 20 bone samples were selected for radiocarbon dating and strontium isotope analysis (87Sr/86Sr), respectively. All samples show preservation from diagenesis, although 87Sr/86Sr contribution from the burial environment cannot be excluded. Therefore, the strontium isotope data are included in the study but are not used in the interpretation of the results. Homogeneous radiocarbon dates of human remains are observed, whereas later dates are obtained for some animal remains, highlighting the continuous use of the monument decades after the conflict. Human individuals have homogeneous δ18Op values, which are consistent with independent numismatic analyses and lead us to propose the Maine region as a potential geographic origin. Heterogeneities of δ13Ccoll and δ15Ncoll values are highlighted between individuals from different structures and are attributed to preferential access to animal protein and different social statuses among the buried warriors. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the olive, iconic tree of the Mediterranean basin, seasonality of (Hg) mercury pollution. Hg concentrations of foliage, stems, soil surface, and litter were analyzed on monthly basis in ancient olive trees growing in two groves in Lebanon, Bchaaleh and Kawkaba (1300 and 672 m.a.s.l respectively). A significantly lower concentration was registered in stems (~7–9 ng/g) with respect to foliage (~35–48 ng/g) in both sites with the highest foliage Hg concentration in late winter-early spring and the lowest in summer. It is noteworthy that olive fruits also have the lowest Hg concentration (~7–11 ng/g). The soil has the highest Hg content (~62–129 ng/g) likely inherited through the cumulated litter biomass (~ 63–76 ng/g). good covariation observed between our foliage Hg time-series analysis and those of pCO2 and Hg concentrations of the atmospheric Northern hemisphere confirms that mercury pollution can be studied through olive trees. More precisely, spring sampling is recommended if the objective is to assess the tree's susceptibility to Hg uptake. This may draw an adequate baseline for global inventories on Hg vegetation uptake and for new studies on olive trees in the Mediterranean for reconstructing regional Hg pollution concentrations in the past and present. [ABSTRACT FROM AUTHOR]

Strategies used by marine vertebrates to regulate their body temperature can result in local variations, and the knowledge of these regional heterothermies is crucial for better understanding the thermophysiologies of extant and extinct organisms. In order to investigate regional heterothermies in vertebrates, we analysed the oxygen isotope composition of phosphatic skeletal elements (δ18 O p) of two endothermic fishes (Thunnus thynnus and Xiphias gladius) and three dolphins (two Delphinus delphis delphis and one Cephalorhynchus commersonii kerguelensis). We observed a consistent link between δ18 O p variations and temperature heterogeneities recorded by classical methods. Our δ18 O p data indicate that: (i) bone hydroxylapatite of the axial skeleton of dolphins mineralise at a warmer temperature than that of the appendicular one, (ii) the skull is the warmest body region in X. gladius, and (iii) T. thynnus possesses high body temperature in the skull and visceral mass region. These results demonstrate the possibility of tracking regional heterothermies in extant marine vertebrates using the δ18 O p , paving the way to direct assessment of thermophysiological specificities of both living and extinct vertebrates. From a palaeoenvironmental perspective, the significant observed δ18 O p variability questions the use of some taxa or random skeletal elements for the reconstruction of palaeoceanographic parameters such as seawater temperature and δ18 O. [ABSTRACT FROM AUTHOR]

The Alps Mountains play a major role in the water cycle at a regional scale in Europe. This mountain range acts as the ‘water tower’ of Europe by storing large volumes of ice and snow, and by regulating the runoff of the rivers constituting freshwater reservoirs of paramount importance for the biodiversity and human activity. Located in the French Southern Alps, the Cerveyrette valley and a high-altitude (≈ 2000 m) swampy plain constitute a watershed of about 100 km². From August 2011 to July 2013, water samples were collected monthly from the Cerveyrette river upstream of the Cervières village (elevation = 1620 m) located in the Upper Durance catchment area. Apparent cyclicality in δ²H and δ18O of the river waters documented over these two years partly reflect seasonal variations in the isotopic compositions of precipitations that mainly occur as snow accumulating at altitudes ranging from ≈ 1700 m to 3300 m. The estimated time lag of three to four months between summer precipitations and their sampling in the Cerveyrette river at the discharge point of the watershed is interpreted to integrate both the mean transfer time of the water discharge and the rate of melting of the snow cover. Here, we show that the transfer time from mountain-accumulated snow toward the low-altitude cultivated areas (Provence) is a sensitive key variable responding to the current climate warming. Indeed, a lowering of the snow cover surface is expected to reduce the buffer effect of snow compared to rainfall, and to decrease the time period during which the discharge rate of the Durance river is large enough for constituting sizable water resources. Understanding and modeling water transit times in nival dominated watersheds are consequently critical to evaluate the impact of the ongoing climate warming on water circulation and resources in the Alps and downstream including the case of mitigation actions. [ABSTRACT FROM AUTHOR]

The Gauls, who occupied most of Western Europe during the Second Iron Age (500 BCE–50 BCE), exploited their environment through farming and trading of local resources. The study of carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) stable isotopes of 8 humans and 12 animals from the Gallic site of Thézy-Glimont, Picardie, France, provides an insight into the dietary practices of this population. Various bones from the cephalic, axial, and appendicular skeletons of three human individuals were sampled to study intra-skeletal stable isotope variability. All bones have similar collagen δ13C, δ15N, and δ34S values for each individual, showing that they followed a consistent diet during their life, and that isotopic compositions are homogeneously recorded in bones despite various turnover rates. The δ13C (− 20.5‰ to − 19.8‰) and δ15N (+ 7.6‰ to + 9.0‰) values indicate that the studied Gallic individuals followed a continental omnivorous diet based on C3-plants and cattle meat. High δ34S values, in the range + 11.7‰ to + 17.7‰, are apparently at variance with these conclusions as they reflect a marine contribution. However, they can also be explained by a more intense regime of precipitation from the westerlies and possible contributions from the geological substratum. While deepening the knowledge of the cultural practices of Gallic tribes from Northern Gaul during the Second Iron Age, this study highlights how stable isotope compositions of body tissues can reflect the interactions between populations and their environment. [ABSTRACT FROM AUTHOR]

Strategies used by marine vertebrates to regulate their body temperature can result in local variations, and the knowledge of these regional heterothermies is crucial for better understanding the thermophysiologies of extant and extinct organisms. In order to investigate regional heterothermy in vertebrates, we analysed the oxygen isotope composition of phosphatic skeletal elements ^18Op) of two poikilothermic (Atlantic bluefin tuna and swordfish) and three homeothermic endotherms (dolphins). We observed a consistent link between δ18Op variations and temperature heterogeneities recorded by classical methods. Our δ18Op data indicate that: (i) bone hydroxyapatite of the axial skeleton of dolphins mineralize at a warmer temperature than that of the appendicular one, (ii) the skull is the warmest body region in swordfish, and (iii) Atlantic bluefin tuna possesses high body temperature in the skull and visceral mass region. These results demonstrate the possibility of tracking regional heterothermies in extant marine vertebrates using the δ1^ρ, paving the way to direct assessment of thermophysiological specificities of both living and extinct vertebrates. From a paleoenvironmental perspective, the significant observed δ18Op variability questions the use of some taxa or random skeletal elements for the reconstruction of paleoceanographic parameters such as seawater temperature and δ1^. [ABSTRACT FROM AUTHOR]

Stable isotope compositions of ancient halite fluid inclusions have been recognized to be valuable tools for reconstructing past environments. Nevertheless, in order to better understand the genesis of halite deposits, it could be of great interest to combine both δ2H and δ18O measurements of the water trapped as inclusions in the defects of the mineral lattice. We developed a method combining off‐axis integrated cavity output spectroscopy (OA‐ICOS) connected on line with a modified elemental analyzer (EA‐OA‐ICOS) to perform those measurements. The first step was to test the method with synthetic halite crystals precipitated in the laboratory from isotopically calibrated waters. Water isotopic signatures have been measured with conventional techniques, equilibration for δ18O and chromium reduction for δ2H. Then, we modified and optimized a conventional EA to connect it online with an OA‐ICOS instrument for H2O measurements. The technique is first evaluated for calibrated free water samples. The technique is also evaluated for salt matrix effect, accuracy, and linearity for both isotopic signatures. Then, the technique is used to measure simultaneously δ2H and δ18O values of halite water inclusions precipitated from the evaporation experiments. Data generated with this new technique appeared to be comparable with those inferred from prior off‐line technique studies. The advantages offered by the OA‐ICOS technique are the simultaneous acquisition of both isotopic ratios and the substantial reduction of data acquisition time and sample aliquot size. Natural halite samples have been analyzed with this method. Natural halite samples as old as Precambrian have also been analyzed with this method. [ABSTRACT FROM AUTHOR]

Summary: Nitrogen (N) assimilation is associated with 14N/15N fractionation such that plant tissues are generally 15N‐depleted compared to source nitrate. In addition to nitrate concentration, the δ15N value in plants is also influenced by isotopic heterogeneity amongst organs and metabolites. However, our current understanding of δ15N values in nitrate is limited by the relatively small number of compound‐specific data.We extensively measured δ15N in nitrate at different time points, in sunflower and oil palm grown at fixed nitrate concentration, with nitrate circulation being varied using potassium (K) conditions and waterlogging.There were strong interorgan δ15N differences for contrasting situations between the two species, and a high 15N‐enrichment in root nitrate. Modelling shows that this 15N‐enrichment can be explained by nitrate circulation and compartmentalisation whereby despite a numerically small flux value, the backflow of nitrate to roots via the phloem can lead to a c. 30‰ difference between leaves and roots. Accordingly, waterlogging and low K conditions, which down‐regulate sap circulation, cause a decrease in the leaf‐to‐root isotopic difference.Our study thus suggests that plant δ15N can be used as a natural tracer of N fluxes between organs and highlights the potential importance of δ15N of circulating phloem nitrate. [ABSTRACT FROM AUTHOR]

Reconstructing the living environment of extinct vertebrates is often challenging due to the lack of proxies. We propose a new proxy to the living environment based on the combined oxygen and sulphur stable isotope analysis of vertebrate hydroxyapatite. We tested this isotopic proxy to 64 biogenic apatite (bones) samples that represent a wide spectrum of the extant vertebrate phylogenetic diversity including crocodiles, snakes, turtles, mammals, birds, lizards, fish and amphibians. We show that the combination of these two isotopic systems allows the living environment of all these vertebrates to be unambiguously distinguished between freshwater (aquatic vs semi-aquatic), seawater (aquatic vs semi-aquatic) and terrestrial. The main goal of this study is to provide a present-day isotopic reference frame and to discuss methodological issues that will serve to interpret future oxygen and sulphur isotope results obtained either from fossil or modern skeletal material. This new isotopic approach of combined oxygen and sulphur isotope analysis will be particularly useful to document major aquatic-terrestrial transitions in the fossil record but also to better constrain the living environment of some present-day species. [ABSTRACT FROM AUTHOR]

Teleosauridae and Metriorhynchidae were thalattosuchian crocodylomorph clades that secondarily adapted to marine life and coexisted during the Middle to Late Jurassic. While teleosaurid diversity collapsed at the end of the Jurassic, most likely as a result of a global cooling of the oceans and associated marine regressions, metriorhynchid diversity was largely unaffected, although the fossil record of Thalattosuchia is poor in the Cretaceous. In order to investigate the possible differences in thermophysiologies between these two thalattosuchian lineages, we analysed stable oxygen isotope compositions (expressed as δ18O values) of tooth apatite from metriorhynchid and teleosaurid specimens. We then compared them with the δ18O values of coexisting endo-homeothermic ichthyosaurs and plesiosaurs, as well as ecto-poikilothermic chondrichthyans and osteichthyans. The distribution of δ18O values suggests that both teleosaurids and metriorhynchids had body temperatures intermediate between those of typical ecto-poikilothermic vertebrates and warm-blooded ichthyosaurs and plesiosaurs, metriorhynchids being slightly warmer than teleosaurids. We propose that metriorhynchids were able to raise their body temperature above that of the ambient environment by metabolic heat production, as endotherms do, but could not maintain a constant body temperature compared with fully homeothermic ichthyosaurs and plesiosaurs. Teleosaurids, on the other hand, may have raised their body temperature by mouth-gape basking, as modern crocodylians do, and benefited from the thermal inertia of their large body mass to maintain their body temperature above the ambient one. Endothermy in metriorhynchids might have been a by-product of their ecological adaptations to active pelagic hunting, and it probably allowed them to survive the global cooling of the Late Jurassic, thus explaining the selective extinction affecting Thalattosuchia at the Jurassic-Cretaceous boundary. [ABSTRACT FROM AUTHOR]

The study of paleoclimates enables us to improve and better constrain climate models in order to forecast future climate variations. Marine Isotope Stage 11 (MIS11), which began around 425,000 yr BP and lasted about 65,000 yr, is a warm isotope stage of paramount importance, because the astronomical configuration was similar to the one characterizing the Holocene. Therefore, this warm isotope stage is the most appropriate analog to present-day climate known to date. This study aims to provide new data on sea-surface temperatures (SSTs) inferred from the carbon and oxygen isotope compositions of skeletal carbonates of marine invertebrates preserved in two marine deposits of the Canary Islands located at Piedra Alta, Lanzarote, and Arucas, Gran Canaria. According to published isotopic fractionation equations the marine deposit from Arucas recorded SSTs of 15.9 ± 2.2°C on average, while the tsunamite from Piedra Alta recorded SSTs of 21.2 ± 1.9°C on average. Absolute dating, mollusc assemblages, and calculated marine temperatures suggest that the Arucas marine deposit corresponds to the beginning of MIS11, while the Piedra Alta tsunamite was formed during MIS11c. These results show that low latitudes also experienced sizable SST changes during interglacial stages. [ABSTRACT FROM AUTHOR]

The large range of stable oxygen isotope values of phosphate‐bearing minerals and dissolved phosphate of inorganic or organic origin requires the availability of in‐house produced calibrated silver phosphate of which isotopic ratios must closely bracket those of studied samples. We propose a simple protocol to synthesise Ag3PO4 in a wide range of oxygen isotope compositions based on the equilibrium isotopic fractionation factor and the kinetics and temperature of isotopic exchange in the phosphate–water system. Ag3PO4 crystals were obtained from KH2PO4 that was dissolved in water of known oxygen isotope composition. Isotopic exchange between dissolved phosphate and water took place at a desired and constant temperature into PYREX™ tubes that were placed in a high precision oven for defined run‐times. Samples were withdrawn at desired times, quenched in cold water and precipitated as Ag3PO4. We provide a calculation sheet that computes the δ18O of precipitated Ag3PO4 as a function of time, temperature and δ18O of both reactants KH2PO4 and H2O at t = 0. Predicted oxygen isotope compositions of synthesised silver phosphate range from −7 to +31‰ VSMOW for a temperature range comprised between 110 and 130 °C and a range of water δ18O from −20 to +15‰ VSMOW. [ABSTRACT FROM AUTHOR]

We demonstrate an improved method based on continuous-flow elemental analyser pyrolysis isotopic ratio mass spectrometry (CF-EA-PY-IRMS) to measure the ²H/¹H ratios of water trapped in halite crystals. Two challenges to overcome are the low hydrogen concentration of samples (10-50 μmol H2·g-1) and the high chloride concentration released when reacting halite in an elemental analyser. We describe an optimization procedure for determining the ²H/¹H ratio of this trapped water with an acceptable accuracy. This technique involves the use of a high-temperature Cr reactor to quantitatively convert H2O into H2. The initial step was performed on halite crystals precipitated from a water reservoir where ²H/¹H ratios were monitored from its initial stage until the end of evaporation. The ²H/¹H isotopic analyses were automated online in continuous-flow mode. Precision of the method was determined for those "synthetic" samples with hydrogen concentrations ranging from 0.2 to 0.5 wt%. ²H/¹H isotopic ratios of evaporating waters bracket the compositions of water inclusions. The formation of fluid inclusions is not instantaneous and records the isotopic signature of the residual waters across a time range during which the isotopic values of the water still evolve. This property explains why the δ²HVSMOW standard deviation of ±5‰ (2σ) observed for 10-mg aliquots of halite exceeds the instrumental error (about ±1.5‰ 2σ) determined on the basis of IAEA-CH7, NBS 30, and NBS 22 references along with calibrated waters with and without added halite crystals. We also applied this method to Mesoproterozoic (1.4 Ga) and Neoproterozoic (0.8 Ga) halite samples with relatively low hydrogen concentrations (300-1500 ppm). The measured δ²HVSMOW values for Precambrian waters range from -89‰to -54‰. We propose that this technique offers a new perspective and great potential for palaeoenvironmental reconstructions based on the ²H/¹H analyses of water trapped in halite. [ABSTRACT FROM AUTHOR]

The fish-to-tetrapod transition—followed later by terrestrialization—represented a major step in vertebrate evolution that gave rise to a successful clade that today contains more than 30,000 tetrapod species. The early tetrapod Ichthyostega was discovered in 1929 in the Devonian Old Red Sandstone sediments of East Greenland (dated to approximately 365 million years ago). Since then, our understanding of the fish-to-tetrapod transition has increased considerably, owing to the discovery of additional Devonian taxa that represent early tetrapods or groups evolutionarily close to them. However, the aquatic environment of early tetrapods and the vertebrate fauna associated with them has remained elusive and highly debated. Here we use a multi-stable isotope approach (δ13C, δ18O and δ34S) to show that some Devonian vertebrates, including early tetrapods, were euryhaline and inhabited transitional aquatic environments subject to high-magnitude, rapid changes in salinity, such as estuaries or deltas. Euryhalinity may have predisposed the early tetrapod clade to be able to survive Late Devonian biotic crises and then successfully colonize terrestrial environments. An approach using multiple stable isotopes reveals that early tetrapods of the Devonian period were euryhaline animals that inhabited aquatic environments of highly variable salinity. [ABSTRACT FROM AUTHOR]

Earthquakes or explosive eruptions generate tsunami, which are at the origin of thick and chaotic coastal sediments. These commonly fossiliferous deposits are formed instantaneously at the historical or geological timescale and therefore have the potential to provide snapshot records of past climates. In Crete, near the city of Palaikastro, crops out a 1- to 9-m-thick sedimentary layer deposited by a huge tsunami that has been previously estimated to be about 9 m high. The presence of volcanic ash, the geometry, the archeological and faunal contents of the sedimentary deposit along with radiocarbon dating converge for interpreting this tsunamite as coeval with the Minoan Santorini (Thera) eruption ≈3350 yr BP. During its drawback, the tsunami deposited rocky blocks and a muddy matrix containing mollusc shells dredged from the seabed as well as cattle skeletal remains and various artifacts belonging to the contemporaneous Minoan civilization. While the oxygen isotope compositions of terrestrial vertebrate bone remains most likely resulted from diagenetic alteration, those of a bovid tooth revealed that air temperatures during MM3 and LM1 periods were about 4°C higher than nowadays. Oxygen isotope measurements of marine mollusc shells also revealed that sea surface temperatures were higher by about 2°C. Those results compare with the 2.5°C temperature difference already estimated according to both δ2H and δ18O values of Greenland ice cores. Incremental sampling of marine gastropods and bovid teeth suggests that the seasonal amplitude was similar to that prevailing during the second half of the 20th century. [ABSTRACT FROM AUTHOR]

Rationale: We have used a high‐precision, high‐efficiency method for the measurement of the ²H/¹H ratios of hydrous silicates (amphiboles) and nominally anhydrous minerals (NAM) such as clinopyroxene, garnet and diamond, which are usually extremely resistant to pyrolysis. This opens up new fields of investigation to better understand the conditions of formation for deep‐Earth minerals. Methods: The technique described here involves Isotope Ratio Mass Spectrometry (IRMS) on‐line in continuous flow mode with an Elemental Analyser (EA) using "purge and trap" technology rather than separation by conventional packed column gas chromatography (GC). The system is equipped with a special high‐temperature furnace reaching 1500°C, with a longer hot zone and improved temperature stability. Emphasis is put on the efficiency of the system to reliably pyrolyse refractory minerals difficult to analyse with other conventional systems. Results: While conventional systems usually fail to generate hydrogen suitable for isotopic analyses, with the technique presented here we were able to measure ²H/¹H ratios from four diamond samples (δ²H = -60, -77, -84 and -79‰ V‐SMOW; average SD = 4.5‰; n = 2), three garnet samples (δ²H from -70 to -63‰), and nine clinopyroxenes (δ²H from -92 to -58‰) associated with seven amphiboles (δ²H from -76 to -27‰) from single mantle rock. Conclusions: The possibility of using such a system to reliably measure ²H/¹H ratios from refractory minerals, which are usually extremely difficult to analyse, offers a new tool of investigation for providing us with unrivaled clues to study the deep interiors of Earth. [ABSTRACT FROM AUTHOR]

In order to determine the incubation temperature of eggs laid by non-avian dinosaurs, we analysed the oxygen isotope compositions of both eggshell carbonate (δ18Oc) and embryo bone phosphate (δ18Op) from seven oviraptorosaur eggs with preserved in ovo embryo bones. These eggs come from the Upper Cretaceous Nanxiong Formation of Jiangxi Province, China. Oviraptorosaur theropods were selected because of their known brooding behaviour as evidenced by preserved adult specimens fossilized in brooding posture on their clutch. Incubation temperature of these embryos was estimated based on the following considerations: eggshell δ18Oc value reflects the oxygen isotope composition of egg water fluid; embryo bones precipitate from the same egg fluid; and oxygen isotope fractionation between phosphate and water is controlled by the egg temperature. A time-dependent model predicting the δ18Op evolution of the embryo skeleton during incubation as a function of egg temperature was built, and measured δ18Oc and δ18Op values used as boundary conditions. According to the model outputs, oviraptorosaurs incubated their eggs within a 35-40°C range, similar to extant birds and compatible with the known active brooding behaviour of these theropod dinosaurs. Provided that both eggshell and embryo bones preserved their original oxygen isotope compositions, this method could be extended to investigate some reproductive traits of other extinct groups of oviparous amniotes. [ABSTRACT FROM AUTHOR]

Objectives Stable isotope data provide insight into the reconstruction of ancient human diet. However, cooking may alter the original stable isotope compositions of food due to losses and modifications of biochemical and water components. Methods To address this issue, carbon, nitrogen and oxygen isotope ratios were measured on meat aliquots sampled from various animals such as pork, beef, duck and chicken, and also from the flesh of fishes such as salmon, European seabass, European pilchard, sole, gilt-head bream, and tuna. For each specimen, three pieces were cooked according to the three most commonly-known cooking practices: boiling, frying and roasting on a barbecue. Results Our data show that cooking produced isotopic shifts up to 1.8‰, 3.5‰, and 5.2‰ for δ13C, δ15N, and δ18O values, respectively. Such variations between raw and cooked food are much greater than previously estimated in the literature; they are more sensitive to the type of food rather than to the cooking process itself, except in the case of boiling. Conclusions Reconstructions of paleodietary may thus suffer slight bias in cases of populations with undiversified diets that are restrained toward a specific raw or cooked product, or using a specific cooking mode. In cases of oxygen isotope compositions from skeletal remains (bones, teeth), they not only constitute a valuable proxy for reconstructing past climatic conditions, but they could also be used to improve our knowledge of past human diet. [ABSTRACT FROM AUTHOR]

The oxygen isotope compositions of bones (n = 11) and teeth (n = 20) from 12 Sudanese individuals buried on Sai Island (Nubia) were analysed to investigate the registration of the evolution of the Nile environment from 3700 to 500 years BP and the potential effects of ontogeny on the oxygen isotope ratios. The isotopic compositions were converted into the composition of drinking water, ultimately originating from the Nile. δ18O values decrease during ontogeny; this is mainly related to breastfeeding and physiology. Those of neonates present very large variations. Neonates have a very high bone turnover and are thus able to record seasonal δ18O variations of the Nile waters. These variations followed a pattern very similar to the present one. Nile δ18O values increased from 1.4 to 4.4 ‰ (Vienna Standard Mean Ocean Water) from the Classic Kerma (∼3500 BP) through the Christian period (∼1000 BP), traducing a progressive drying of Northeast Africa. [ABSTRACT FROM AUTHOR]

Rationale In ecological studies, the sulfur isotope compositions (δ34S values) of soft tissues (e.g. hair, skin, nail, muscle, collagen) allow the determination of both past and present-day living environments of organisms. However, technical limitations have so far prevented reliable sulfur isotope analyses of minerals having low sulfur content, such as bioapatite, which is the crystalline component of skeletal tissues. The development of 'purge-and-trap' technology in elemental analysers recently demonstrated new possibilities to solve some of those technical difficulties. Methods We have used a VarioPYROcube elemental analyser (EA) equipped with 'purge-and-trap' technology, interfaced in continuous flow mode to an Isoprime 100 isotope ratio mass spectrometer, to measure the sulfur isotope compositions of bioapatite samples. We first characterised a working calibrated material of chemical composition close to those of our samples, the low-S bearing phosphorite BCR32, against the two δ34SV-CDT reference-calibrated materials, NBS-127 and IAEA-SO-5. We have confirmed a δ34SV-CDT value of +18.4‰ (1 σ = 0.5; n = 18) in agreement with the previously published value. Using BCR32 as a compositional and isotopic reference material, we have then measured the δ34SV-CDT values of various bioapatite tissues (bone, dentine and enamel) from both modern and fossil vertebrates living in different environments (marine, freshwater and terrestrial). Results Our results demonstrate the capacity of this analytical setup to measure the δ34SV-CDT values of low-S bioapatite samples (0.14 to 1.19 wt%) with a good analytical precision (1 σ = 0.5; n = 14). Our results also show that the δ34SV-CDT values of modern and fossil vertebrate bioapatites allow discrimination between marine environments and freshwater or terrestrial ones. Conclusions Sulfur isotope analysis of bioapatite has great potential to track the living environment of extinct vertebrates for which only fossilised bones or teeth have been preserved. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper (65Cu/63Cu) and sulfur (34S/32S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is 63Cu-enriched by ∼0.4‰ and sulfur is 32S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The 32S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide newmeans to detect and quantify cancermetabolic changes and provide insights into underlying mechanisms. [ABSTRACT FROM AUTHOR]

This study investigates the effect of biological and environmental inter-individual variability on the meaning of δ18O and δ13C values acquired on small carbonated shells. First we present data obtained with a MultiPrep automated carbonate system on small sample sizes of a homogeneous carbonate material: Carrara marble. This demonstrates the capacities of the analytical system to reliably run small amounts of carbonates even down to 10 μg. Then we present two data sets obtained on real fossil samples of v arious s ize ( sensu number of individual organisms) calibrated against the NBS19 carbonate standard. Both datasets evidence a clear trend of between-biological sample standard deviation increase for both δ18O and δ13C measurements when the number of pooled specimens per sample decreases. According to the results obtained from a systematic study of a geologically homogeneous sample of coeval fossil Elphidium foraminifera, we estimate that there is 95% of chances to reach between-biological sample standard deviation values higher than 1.02% (δ18O) and 1.45% δ13C) based on single-cell measurements. Such values are one order of magnitude higher than the instrumental standard deviations associated with these stable isotope ratios. Conversely, a minimum of 35 (δ18O) and 44 (δ13C) pooled specimens of Elphidium appears necessary to reach a between-sample standard deviation ≤ 0.25%. with a probability of 95%. Such biological intrinsic and irreducible variability between coeval individuals, and thus samples, clearly questions the interest for single-cell analyses, more precisely, for coastal marine species, such as Elphidium, subject to many environmental changes during their lifetime. Indeed, strong variations in salinity or temperature, as well as biogenic fractionation, could influence the isotopic composition of an individual specimen. Results might be less problematic for an average community including several tests. This paper underlines uncertainties linked to specific environments in which selected organisms live, especially for paleoceanographic or paleoclimatic reconstruction purposes where secular oxygen and carbon isotope variations typically range from 0.5 to 1.5%. [ABSTRACT FROM AUTHOR]

RATIONALE The evolution of stable isotope applications has demonstrated the increasing need for the determination of more than one isotopic signature from the same sample. Simultaneous determinations of 13C/12C and 15 N/14 N have become a widespread technique but up to now very few fully automated systems have offered the possibility of also measuring 34S/32S from the same sample aliquot. This could be critical when sample amounts are limited, but it could also represent a significant gain of analytical time or cost. The technique that we are presenting provides these multiple isotopic signatures on small sample aliquots with high precisions, especially for sulfur determinations. METHODS A high-precision, easy and rapid method for the simultaneous measurement of carbon (13C/12C), nitrogen (15 N/14 N) and sulfur (34S/32S) ratios as well as elemental concentrations was employed, using a new combination of an elemental analyzer and an isotope ratio mass spectrometer. The elemental analyzer was based on 'purge and trap' technology rather than conventional packed-gas chromatography (GC) gas separation. Emphasis was put on the efficiency of the system to reliably combust sulfur-bearing compounds of both organic and inorganic origin with high conversion yields. RESULTS High-quality measurement of 34S/32S ratios was obtained using various international reference materials. A working calibrated material was also selected and characterized for all three isotopic signatures in order to fully use the capacities of the system in future work. CONCLUSIONS The possibilities of such a system for the reliable measurement of S isotope ratios as well as N and C isotope ratios within the same aliquot of sample opens up new fields of investigation in many domains where multi-isotopic approaches are required. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The middle Paleolithic stratigraphic sequence of Les Pradelles (Charente, France) spans from the end of Marine Isotope Stage (MIS) 4 until the middle of MIS 3. Micromammal remains are present in all the stratigraphic levels, offering a rare opportunity to address the questions of both environmental and climatic fluctuations throughout this period. Climate modes were studied through the taphonomy, biodiversity and oxygen isotope compositions of phosphate (δ18Op) from 66 samples of rodent tooth enamel. The δ18Op values from the lower sedimentary levels provide summer mean air temperatures of 19±2°C (level 2/1) and of 16±2°C (levels 2A, 2B and 4A). Within the middle of sequence (level 4B), a paleobiodiversity change can be identified with an increase of Dicrostonyx torquatus, which is associated with the largest amplitude in δ18Op values and the highest maximal δ18Op values. At the top of the sequence (level 5-2), a biodiversity change is observed with the increase of Microtus arvalis, but without any change in δ18Op values. The association of cold rodent species with unexpected high and large amplitudes in the δ18Op values of their teeth, possibly indicative of aridity, suggests their deposition during a Heinrich event. [ABSTRACT FROM AUTHOR]

Summary 1. The evolution of strategies of resource acquisition and allocation is often considered to be closely dependent on the degree of environmental variability. Within this framework, female insects that experience stochastic fluctuations in the availability of their egg-laying sites in time or space can be expected to be fully synovigenic (i.e. they start maturing eggs after a delay once reaching adulthood), which allows them to tailor their reproductive investment to variations in the resource. Proovigenic females (that have most of their eggs already mature at the onset of their adult life, which corresponds to a capital breeding strategy), on the contrary, should have an advantage when the availability of the egg-laying sites is predictable. There is, however, a dearth of empirical studies testing these predictions. 2. Here, we tested the hypothesis that four phytophagous insect species of the genus Curculio, which coexist on a strongly fluctuating resource that they exploit for egg-laying purposes, would all be synovigenic as strict proovigeny should be counterselected. The resource consisted of the acorns of oak trees Quercus spp. We conducted field surveys to determine the date of adult emergence in each weevil species and the ability of newly emerged females to produce eggs. We also analysed the stable isotope profile of wild-caught females as a proxy for their feeding activity. Finally, we tested females under laboratory conditions for their ability to produce mature eggs when not fed and investigated whether dietary intake influenced their longevity. 3. Taken together, our results show that, contrary to the usual predictions, the four weevil species that were all exposed to a markedly fluctuating environment exhibited sharply contrasting strategies of resource acquisition and allocation: three species were synovigenic, while the fourth was proovigenic. Unexpectedly, therefore, our findings show that a strict capital breeding species might not always be counterselected in a temporally stochastic environment. They further suggest that fluctuations in the environment should not promote a sole, optimal strategy of energy acquisition and allocation to reproduction but instead should favour their diversification. [ABSTRACT FROM AUTHOR]

Abstract: Oxygen isotope compositions of phosphate in tooth enamel from large mammals (i.e. horse and red deer) were measured to quantify past mean annual air temperatures and seasonal variations between 145ka and 33ka in eastern France. The method is based on interdependent relationships between the δ18O of apatite phosphate, environmental waters and air temperatures. Horse (Equus caballus germanicus) and red deer (Cervus elaphus) remains have δ18O values that range from 14.2‰ to 17.2‰, indicating mean air temperatures between 7°C and 13°C. Oxygen isotope time series obtained from two of the six horse teeth show a sinusoidal-like signal that could have been forced by temperature variations of seasonal origin. Intra-tooth oxygen isotope variations reveal that at 145ka, winters were colder (−7±2°C) than at present (3±1°C) while summer temperatures were similar. Winter temperatures mark a well-developed West–East thermal gradient in France of about −9°C, much stronger than the −4°C difference recorded presently. Negative winter temperatures were likely responsible for the extent and duration of the snow cover, thus limiting the food resources available for large ungulates with repercussions for Neanderthal predators. [Copyright &y& Elsevier]

1. The functional feeding group approach has been widely used to describe the community structure of benthic invertebrates in relation to organic matter resources. Based on this functional framework, positive interactions between feeding groups (especially shredders and collector-gatherers) were postulated in the River Continuum Concept. However, relationships with organic matter have been poorly documented for invertebrates living in the hyporheic zone. 2. We hypothesised that the common subterranean amphipod Niphargus rhenorhodanensis would feed on fine particulate organic matter (FPOM), which is more abundant than coarse particulate organic matter (CPOM) in hyporheic habitats, and should be favoured by the occurrence of shredders that produce FPOM from CPOM. 3. We used laboratory experiments to quantify leaf litter processing by N. rhenorhodanensis and a common shredder, the surface amphipod Gammarus roeselii. We estimated rates of feeding and assimilation (using nitrogen stable isotopes) of the two species separately and together to reveal any potential shredder-collector facilitation between them. 4. Measured leaf litter mass loss showed that N. rhenorhodanensis did not act as a shredder, unlike G. roeselii. Organic matter dynamics and N/N ratios in tissues of niphargids indicated that N. rhenorhodanensis was a collector-gatherer feeding preferentially on FPOM. We also found a positive influence of the gammarid shredders on the assimilation rate of N. rhenorhodanensis, which fed on FPOM produced by the shredders, supporting the hypothesis of a positive interaction between surface shredders and hyporheic collector-gatherers. [ABSTRACT FROM AUTHOR]

Millions of mummified birds serving for religious purpose have been discovered from archeological sites along the Nile Valley of Egypt, in majority ibises. Whether these birds were industrially raised or massively hunted is a matter of heavy debate as it would have a significant impact on the economy related to their supply and cult, and if hunted it would have represented an ecological burden on the birds populations. Here we have measured and analysed the stable oxygen, carbon and radiogenic strontium isotope compositions as well as calcium and barium content of bones along with the stable carbon, nitrogen and sulfur isotope composition of feathers from 20 mummified ibises and birds of prey recovered from various archeological sites of Ancient Egypt. If these migratory birds were locally bred, their stable oxygen, radiogenic strontium and stable sulfur isotopic compositions would be similar to that of coexisting Egyptians, and their stable carbon, nitrogen and oxygen isotope variance would be close, or lower than that of Egyptians. On one hand, isotopic values show that ibises ingested food from the Nile valley but with a higher isotopic scattering than observed for the diet of ancient Egyptians. On the other hand, birds of prey have exotic isotopic values compatible with their migratory behaviour. We therefore propose that most mummified ibises and all the birds of prey analysed here were wild animals hunted for religious practice. [ABSTRACT FROM AUTHOR]