We used high-sensitivity, high-resolution tandem mass spectrometry to shotgun sequence ancient protein remains extracted from a 43 000 year old woolly mammoth ( Mammuthus primigenius ) bone preserved in the Siberian permafrost. For the first time, 126 unique protein accessions, mostly low-abundance extracellular matrix and plasma proteins, were confidently identified by solid molecular evidence. Among the best characterized was the carrier protein serum albumin, presenting two single amino acid substitutions compared to extant African ( Loxodonta africana ) and Indian ( Elephas maximus ) elephants. Strong evidence was observed of amino acid modifications due to post-mortem hydrolytic and oxidative damage. A consistent subset of this permafrost bone proteome was also identified in more recent Columbian mammoth ( Mammuthus columbi ) samples from temperate latitudes, extending the potential of the approach described beyond subpolar environments. Mass spectrometry-based ancient protein sequencing offers new perspectives for future molecular phylogenetic inference and physiological studies on samples not amenable to ancient DNA investigation. This approach therefore represents a further step into the ongoing integration of different high-throughput technologies for identification of ancient biomolecules, unleashing the field of paleoproteomics.
The earliest dispersal of humans into North America is a contentious subject, and proposed early sites are required to meet the following criteria for acceptance: (1) archaeological evidence is found in a clearly defined and undisturbed geologic context; (2) age is determined by reliable radiometric dating; (3) multiple lines of evidence from interdisciplinary studies provide consistent results; and (4) unquestionable artefacts are found in primary context. Here we describe the Cerutti Mastodon (CM) site, an archaeological site from the early late Pleistocene epoch, where in situ hammerstones and stone anvils occur in spatio-temporal association with fragmentary remains of a single mastodon (Mammut americanum). The CM site contains spiral-fractured bone and molar fragments, indicating that breakage occured while fresh. Several of these fragments also preserve evidence of percussion. The occurrence and distribution of bone, molar and stone refits suggest that breakage occurred at the site of burial. Five large cobbles (hammerstones and anvils) in the CM bone bed display use-wear and impact marks, and are hydraulically anomalous relative to the low-energy context of the enclosing sandy silt stratum. Th/U radiometric analysis of multiple bone specimens using diffusion-adsorption-decay dating models indicates a burial date of 130.7 ± 9.4 thousand years ago. These findings confirm the presence of an unidentified species of Homo at the CM site during the last interglacial period (MIS 5e; early late Pleistocene), indicating that humans with manual dexterity and the experiential knowledge to use hammerstones and anvils processed mastodon limb bones for marrow extraction and/or raw material for tool production. Systematic proboscidean bone reduction, evident at the CM site, fits within a broader pattern of Palaeolithic bone percussion technology in Africa, Eurasia and North America. The CM site is, to our knowledge, the oldest in situ, well-documented archaeological site in North America and, as such, substantially revises the timing of arrival of Homo into the Americas.
High-quality cryptocrystalline silicates from the Oligocene-age White River Group of the central Great Plains (referred to here as White River Group Silicates [WRGS]) were widely used prehistorically for chipped-stone tools. There are three known source areas for WRGS: Flattop Butte in northeastern Colorado, Table Mountain in east central Wyoming, and the White River Badlands of South Dakota. Specimens from these sources are often visually indistinguishable, making it difficult to specify the source of WRGS from nonquarry archaeological sites. Using a quantitative method—neutron-activation analysis—these sources were differentiated. The sources of WRGS in two Central Plains archaeological sites also were determined using this technique. The results show that the technique has important implications for studies of prehistoric mobility and for the refinement of cultural-historical affiliation.
The Farmdale Soil occurs below late Wisconsinan loess throughout the U.S. Midwest. At the La Sena site in the central Great Plains, humates in the Farmdale Interstadial Soil have a corrected age of 21,000 yr B.P. Humates in a buried Bt horizon and a bulk sample of overlying loess 2.5 m above the Farmdale Interstadial Soil have ages of 17,000 and 19,000 yr B.P., respectively. In the Republican River Valley Picea (spruce) charcoal is common in the lower meter of Peoria loess. Near Bloomington, Nebraska, humates from burned organic matter only 60 cm above the base of Peoria loess have a corrected age of ca. 19,000 yr B.P.
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