Robust High-Throughput Proteomics Identification and Deamidation Quantitation of Extinct Species up to Pleistocene with Ultrahigh-Resolution MALDI-FTICR Mass Spectrometry.

Peptide mass fingerprinting (PMF) using MALDI-TOF mass spectrometry allows the identification of bone species based on their type I collagen sequence. In the archaeological or paleontological field, PMF is known as zooarchaeology mass spectrometry (ZooMS) and is widely implemented to find markers for most species, including the extinct ones. In addition to the identification of bone species, ZooMS enables dating estimation by measuring the deamidation value of specific peptides. Herein, we report several enhancements to the classical ZooMS technique, which reduces to 10-fold the required bone sample amount (down to the milligram scale) and achieves robust deamidation value calculation in a high-throughput manner. These improvements rely on a 96-well plate samples preparation, a careful optimization of collagen extraction and digestion to avoid spurious post-translational modification production, and PMF at high resolution using matrix-assisted laser desorption ionization Fourier transform ion cyclotron resonance (MALDI-FTICR) analysis. This method was applied to the identification of a hundred bones of herbivores from the Middle Paleolithic site of Caours (Somme, France) well dated from the Eemian Last Interglacial climatic optimum. The method gave reliable species identification to bones already identified by their osteomorphology, as well as to more challenging samples consisting of small or burned bone fragments. Deamidation values of bones originating from the same geological layers have a low standard deviation. The method can be applied to archaeological bone remains and offers a robust capacity to identify traditionally unidentifiable bone fragments, thus increasing the number of identified specimens and providing invaluable information in specific contexts.

An ecological niche shift for Neanderthal populations in Western Europe 70,000 years ago.

Middle Paleolithic Neanderthal populations occupied Eurasia for at least 250,000 years prior to the arrival of anatomically modern humans. While a considerable body of archaeological research has focused on Neanderthal material culture and subsistence strategies, little attention has been paid to the relationship between regionally specific cultural trajectories and their associated existing fundamental ecological niches, nor to how the latter varied across periods of climatic variability. We examine the Middle Paleolithic archaeological record of a naturally constrained region of Western Europe between 82,000 and 60,000 years ago using ecological niche modeling methods. Evaluations of ecological niche estimations, in both geographic and environmental dimensions, indicate that 70,000 years ago the range of suitable habitats exploited by these Neanderthal populations contracted and shifted. These ecological niche dynamics are the result of groups continuing to occupy habitual territories that were characterized by new environmental conditions during Marine Isotope Stage 4. The development of original cultural adaptations permitted this territorial stability.

The earliest evidence of Acheulian occupation in Northwest Europe and the rediscovery of the Moulin Quignon site, Somme valley, France.

The dispersal of hominin groups with an Acheulian technology and associated bifacial tools into northern latitudes is central to the debate over the timing of the oldest human occupation of Europe. New evidence resulting from the rediscovery and the dating of the historic site of Moulin Quignon demonstrates that the first Acheulian occupation north of 50°N occurred around 670-650 ka ago. The new archaeological assemblage was discovered in a sequence of fluvial sands and gravels overlying the chalk bedrock at a relative height of 40 m above the present-day maximal incision of the Somme River and dated by ESR on quartz to early MIS 16. More than 260 flint artefacts were recovered, including large flakes, cores and five bifaces. This discovery pushes back the age of the oldest Acheulian occupation of north-western Europe by more than 100 ka and bridges the gap between the archaeological records of northern France and England. It also challenges hominin dispersal models in Europe showing that hominins using bifacial technology, such as Homo heidelbergensis, were probably able to overcome cold climate conditions as early as 670-650 ka ago and reasserts the importance of the Somme valley, where Prehistory was born at the end of the 19th century.