Laser ablation depth profiling of U-series and Sr isotopes in human fossils

We have explored laser depth profiling to obtain data sets for U-series as well as Sr analyses. Laser probing with an 81 μm spot size allows for the exploration of low uranium domains of up to 400 μm below the outer surface in tooth enamel. These low U domains will contain Sr isotope compositions of the individual, that are least affected by diagenetic Sr overprints. The small holes drilled for U surveying are not visible to the naked eye. Using larger spot sizes of around 233 μm, laser drilling can be used to obtain reliable U-series isotope data to a depth of approximately 1000 μm in enamel and around 1300 μm in bone. Furthermore, meaningful ⁸⁷Sr/⁸⁶Sr isotope data can also be obtained with this spot size. Using our sampling strategy, the overall damage to a human tooth is minute, as demonstrated on a Neanderthal tooth from Moula-Guercy. We expect that laser ablation depth profiling will become routine for gaining insights into the age of human fossils and the migrations of ancient humans.     

Morphometry of Middle Bronze Age palstaves. Part II – spatial distribution of shapes in two typological groups,implications for production and exportation

For archaeologists, metallic artifacts are key materials to assess Middle Bronze Age production areas and cultural exchanges. Here, a set of 629 bronze palstaves excavated in northern France, belonging to Breton and Norman typological groups, was treated by (open) outline-based morphometrics with orthogonal polynomial regression. Using robust statistics developed for outlier detection, these Norman and Breton palstave outlines can be divided into two groups: those for which the shape fluctuates close to the standard shape, called “congruent” axes, and those which are far enough from this standard to be considered as “non-congruent”, although they possess most of the features of the typological group. The highest density of discovery (whether congruent and non-congruent in shape) is in the extreme east of Brittany for the Breton axes, while the Norman axes are concentrated in northern Normandy, hence the choice of names. However, the distribution of congruent and non-congruent artifacts appears to be spatially dependent for the Norman group, and to a lesser extent for the Breton group, as there are proportionally more congruent specimens inside the supposed production areas than outside. This contradicts the generally accepted archaeological scheme which hypothesizes that all axes in a group originate from the same production center, and that some items were exported from there to supply neighboring regions. Other minor production centers probably existed, copying the original model with greater shape variation.     

Application of GIS methods to retrieve orientation patterns from imagery; a case study from Beds I and II,Olduvai Gorge (Tanzania)

The role of natural processes in the formation of the Bed I and II sites at Olduvai Gorge (Tanzania) remains the subject of much debate, five decades after their original excavation. Preferred orientation of items is indicative of water disturbance, but compass bearings were not available in Mary Leakey's (1971) study. Using GIS methods, we have vectorized maps from 1960s excavations at Olduvai, and applied a range of statistical techniques to calculate items strike. The GIS analysis suggests strongly preferred orientation patterns in Bed I, and more heterogeneous angular histograms in Bed II. Two complementary lines of evidence support these results. Firstly, modelling of potential mapping errors provides a large interval of confidence for preferred orientation patterns. Second, the GIS study was extended to photographs of the earlier excavations and to maps from recent fieldwork at Olduvai; both yielded patterned arrangement of lithics and bones, and are consistent with results based on the analysis of the 1960s maps, i.e. a large number of the Bed I and II assemblages are preferentially oriented. These results highlight the potential of GIS applications to the analysis of imagery in Stone Age studies, and bear important implications for the understanding of the role of natural agents in site formation processes at Olduvai.     

Retention of hunter–gatherer economies among maritime foragers from Caleta Vitor,northern Chile,during the late Holocene: evidence from stable carbon and nitrogen isotopic analysis of skeletal remains

On the basis of stable carbon and nitrogen isotope analysis of human remains, this paper provides evidence for the retention of hunter–gatherer economies among coastal inhabitants in northern Chile during the late Holocene – at the same time that inland populations were adopting agricultural economies. Coastal diets from the Caleta Vitor region of the Atacama Desert were dominated by marine-based foods, predominantly from upper trophic levels. The focus on reliable marine food resources is interpreted as a risk minimisation strategy in this marginal arid environment. Although these coastal hunter–gatherers adopted other goods and traditions from agricultural populations, their participation in this larger interregional exchange network did not affect their basic subsistence economies.     

Residential mobility and social identity in the periphery: strontium isotope analysis of archaeological tooth enamel from southeastern Arabia

Strontium isotope analysis represents an effective means of assessing mobility and reconstructing geographic residence patterns in archaeological populations. This biogeochemical technique was utilized to test the hypothesis that burgeoning interregional exchange networks and the occurrence of exotic grave goods in local tombs would correspond with a highly mobile population and a considerable immigrant presence during the Umm an-Nar (2700–2000 BC) period in the UAE. This region has been considered peripheral relative to larger civilizations in Mesopotamia and the Indus Valley, but played an important role as a major supplier of copper for the Persian Gulf. Individuals (n = 100) from six monumental Umm an-Nar tombs (Mowaihat; Tell Abraq; Umm an-Nar Island I, II, V; Unar 1) were selected to evaluate the geographic origins of tomb members. Mean ⁸⁷Sr/⁸⁶Sr ratios from local individuals interred at Mowaihat (0.708863 ± 0.000014; 1σ, n = 12), Tell Abraq (0.708873 ± 0.000020; 1σ, n = 27), Umm an-Nar Island (0.708902 ± 0.000079; 1σ, n = 33), and Unar 1 (0.708805 ± 0.000065; 1σ, n = 25) all display little isotopic variability, indicative of a population that was not highly mobile. However, coupled with archaeological evidence, three immigrants from Tell Abraq (n = 2) and Mowaihat (n = 1) identified by deviant strontium values suggest that this region was actively engaged in interregional interaction. Despite claims that these tombs acted as visible markers of territoriality legitimized by local ancestors buried within them, the presence of non-locals suggests that as commerce became increasingly important, definitions of kinship and social identity may have become more flexible to better meet the needs of the local community and those with whom they interacted.     

Evaluation of treated and un-treated Nubia Sandstone using ultrasonic as a non-destructive technique

Deterioration factors, both “exogenous” and “endogenous”, are major sources of damaging monumental stones in Egypt. In the current study, the change state of one of the major Egyptian stones (Nubia Sandstone) is investigated and evaluated before and after consolidation by the use of wave velocity as a new method for detecting its elasticity modulus. Wave velocity propagation (Vp) is one of the most important and effective methods for estimating the durability of monumental stones without using any other harmful method as a compressive strength. This technique is usually used for a number of purposes, the first of which is the qualification of masonry building through its morphology and detection of internal defects (e.g. voids and cracks). The second is the examination of the changes of material physical properties, and the control conservation procedures. Third, it is used with some samples of Nubia sandstone for a laboratory test. The study concludes that the durability of samples increases due to the increase of material compacting as a direct result of using consolidant materials. Using the Vp as a non-destructive technique in examining monumental materials gives the same results of other harmful techniques.     

Paleodietary analysis of a San Francisco Bay Area shellmound: stable carbon and nitrogen isotope analysis of late Holocene humans from the Ellis Landing site (CA-CCO-295)

The late Holocene archaeofaunal record of the San Francisco Bay Area demonstrates temporal declines in the abundance of low-cost, high-ranked marine and terrestrial resources. During later periods of occupation, faunal assemblages are often dominated by lower-ranked, higher-cost resources, suggesting an increase in diet breadth through time. Archaeological resource intensification models argue that this marks a late Holocene decline in foraging efficiency in the Bay Area, driven by human-induced harvest pressure. This study examines dietary change in the region using stable carbon and nitrogen isotope data from 65 human burials, spanning two temporal components (cal AD 55–890 and cal AD 762–1550) at the Ellis Landing site (CA-CCO-295). The strong linear relationship between collagen carbon and nitrogen isotope values reflects both marine and terrestrial food consumption, with individuals showing a high level of dietary variability at the site. No temporal trend or meaningful sex differences were found in isotope values. The widening of diet breadth predicted by the archaeofaunal record occurred prior to the occupation of the Ellis Landing shellmound site. The trend in exploiting a greater amount of terrestrial resources during the Middle and Late Period in central California was supported by isotopic evidence.     

Chemical characterisation of anthro-technosols from Bronze to Middle Age in Bologna (Italy)

The aim of this research was the understanding of a peculiarly expanded soil sequence in Bologna (i.e., Roman Bononia, Etruscan Felsina), one of the most important archaeological poles for Etruscan colonisation and settlement in northern Italy. The uppermost part of the chronological sequence dating from the Bronze Age up to medieval and modern times was analysed for the first time from geochemical and pedological viewpoints. The integration of archaeological, stratigraphical and pedological data supported by soil chemical analysis, a fundamental key for reconstructing a correct evolutionary sequence, made it possible to recognise seventeen buried Soil Units (ancient Technosols, Anthrosols and Cambisols) characterised by different kinds and degrees of intensity of anthropogenic influence. In some cases, the results show a relatively severe element concentration (Cu, Sn) mainly characterising the Iron Age (Etruscan and Villanovan) stratigraphic units, representing an ancient industrial pollution linked to local dispersal of melting activity dump products generated in near-site surrounding areas. Therefore, a comparison was possible between natural blank and anthropogenically polluted geochemical values for some local soils.     

Postcranial functional adaptations in the South American Miocene borhyaenoids (Mammalia,Metatheria): Cladosictis,Pseudonotictis and Sipalocyon

Three Santacrucian borhyaenoids, Cladosictis patagonica, Pseudonotictis pusillus and Sipalocyon gracilis, are analyzed from a functional-adaptive perspective. Five extant placentals and one marsupial model are also examined in order to interpret the locomotor adaptations of these fossils. Pseudonotictis pusillus is the smallest of the Santacrucian borhyaenoids and is known from fragmentary remains; from its small size, dental specializations and elbow anatomy, this species was certainly not far ecologically from an extant weasel. The postcranium of Sipalocyon gracilis, although poorly known, suggests climbing capabilities, and the pseudo-opposable pollex indicates skilful manipulative behaviour. Cladosictis patagonica was an active predatory form, short-legged and able to climb, although it was a less specialized arboreal form than the contemporaneous Prothylacinus patagonicus; the proportions of its limbs recall that of a living South American marten, the tayra. The pseudo-opposable pollex of Cladosictis, as in Sipalocyon, indicates skilful manipulative behaviour.     

Phylogenetic interpretation of eggs and eggshells: implications for phylogeny of Palaeognathae

This oological analysis supports Palaeognathae monophyly, and places Dromornithidae within Neognathae, the sister clade of Paleognathae. This Dromornithidae relationship is congruent with a recent phylogenetic hypothesis, based on cranial characters, that differs from the original assignment of this group of extinct birds to the Palaeognathae. Minor differences exist between previous palaeognath phylogenetic hypotheses and that obtained from this research. Some of the topological disparities might be influenced solely by inclusion of more fossil taxa in this analysis compared with those considering either molecular or skeletal characters. Surprisingly, oological data differentiate the Australasian palaeognath taxa from those of Africa and South America; this phylogenetic topology conforms to the paleognath geographic distribution.

Regardless of the issues related to Paleognathae, results show that oological characters permit the differentiation of groups at a generic level, thus validating the use of eggs and eggshells as a source of evolutionary characters.