Homogeneity, mass fractions of about forty trace elements and Sr isotope composition of Ca carbonate reference materials (RMs) between original and nano‐powdered pellets are compared. Our results using nanosecond and femtosecond LA‐(MC)‐ICP‐MS show that the nano‐pellets of the RMs MACS‐3NP, JCp‐1NP and JCt‐1NP are about a factor of 2–3 more homogeneous than the original samples MACS‐3, JCp‐1 and JCt‐1, and are therefore much more suitable for microanalytical purposes. With the exception of Si, the mass fractions of the synthetic RM MACS‐3 agree with its fine‐grained analogue MACS‐3NP. Very small, but significant, differences between original and nano‐pellets are observed in the RMs JCp‐1 and JCt‐1 for some trace elements with very low contents, indicating the need for re‐certification. Strontium mass fractions in the analysed RMs are high (1500–7000 mg kg−1), and their isotope compositions determined by LA‐MC‐ICP‐MS in the original and the nano‐pellets agree within uncertainty limits.

The early onset of weaning in modern humans has been linked to the high nutritional demand of brain development that is intimately connected with infant physiology and growth rate. In Neanderthals, ontogenetic patterns in early life are still debated, with some studies suggesting an accelerated development and others indicating only subtle differences vs. modern humans. Here we report the onset of weaning and rates of enamel growth using an unprecedented sample set of three late (∼70 to 50 ka) Neanderthals and one Upper Paleolithic modern human from northeastern Italy via spatially resolved chemical/isotopic analyses and histomorphometry of deciduous teeth. Our results reveal that the modern human nursing strategy, with onset of weaning at 5 to 6 mo, was present among these Neanderthals. This evidence, combined with dental development akin to modern humans, highlights their similar metabolic constraints during early life and excludes late weaning as a factor contributing to Neanderthals’ demise.

In situ laser ablation analyses rely on the microanalytical homogeneity of reference materials (RMs) and a similar matrix and mass fraction between unknown samples and RMs to obtain reliable results. Suitable carbonate and phosphate RMs for determination of Sr isotope ratios in such materials are limited. Thus, we determined 87Sr/86Sr ratios of several carbonate (JCt-1, JCp-1, MACS-1, MACS-3) and phosphate (MAPS-4, MAPS-5, NIST SRM 1400, NIST SRM 1486) international RMs using dissolved samples and two different multi-collector inductively coupled plasma-mass spectrometers (MC-ICP-MS). Our Sr isotope data are in agreement with published data and have an improved measurement precision for some RMs. For MACS-1, we present the first 87Sr/86Sr value. We tested the suitability of these materials for microanalytical analyses by LA-MC-ICP-MS, with two different laser ablation systems: a conventional nanosecond laser and a state-of-the-art femtosecond laser. We investigated the RMs micro-homogeneity and compared the data with our solution data. Both laser ablation systems yielded identical 87Sr/86Sr ratios within uncertainty to the solution data for RMs with low interferences of REEs. Therefore, these carbonate and phosphate RMs can be used to achieve accurate and precise results for in situ Sr isotope investigations by LA-MC-ICP-MS of similar materials

Recent work has disclosed the critical role played by enamel peptides in sex classification of old skeletal remains. In particular, protein AMELY (amelogenin isoform Y) is present in the enamel dental tissue of male individuals only, while AMELX (isoform X) can be found in both sexes. AMELY can be easily detected by LC-MS/MS in the ion extracted chromatograms of the SM(ox)IRPPY peptide (monoisotopic [M + 2 H]+2 mass = 440.2233 m/z). In this paper, we exploited the dimorphic features of the amelogenin protein to determine the sex of the so-called ‘Lovers of Modena’, two Late Antique individuals whose skeletons were intentionally buried hand-in-hand. Upon discovery, mass media had immediately assumed they were a male-female couple, even if bad preservation of the bones did not allow an effective sex classification. We were able to extract proteins from the dental enamel of both individuals (~1600 years old) and to confidently classify them as males. Results were compared to 14 modern and archaeological control samples, confirming the reliability of the ion chromatogram method for sex determination. Although we currently have no information on the actual relationship between the ‘Lovers of Modena’ (affective? Kin-based?), the discovery of two adult males intentionally buried hand-in-hand may have profound implications for our understanding of funerary practices in Late Antique Italy.