Identification and quantification of projectile impact marks on bone: new experimental insights using osseous points

Shifts in projectile technology potentially document human evolutionary milestones, such as adaptations for different environments and settlement dynamics. A relatively direct proxy for projectile technology is projectile impact marks (PIM) on archaeological bones. Increasing awareness and publication of experimental data sets have recently led to more identifications of PIM in various contexts, but diagnosing PIM from other types of bone-surface modifications, quantifying them, and inferring point size and material from the bone lesions need more substantiation. Here, we focus on PIM created by osseous projectiles, asking whether these could be effectively identified and separated from lithic-tipped weapons. We further discuss the basic question raised by recent PIM research in zooarchaeology: why PIM evidence is so rare in archaeofaunal assemblages (compared to other human-induced marks), even when they are explicitly sought. We present the experimental results of shooting two ungulate carcasses with bone and antler points, replicating those used in the early Upper Paleolithic of western Eurasia. Half of our hits resulted in PIM, confirming that this modification may have been originally abundant. However, we found that the probability of a skeletal element to be modified with PIM negatively correlates with its preservation potential, and that much of the produced bone damage would not be identifiable in a typical Paleolithic faunal assemblage. This quantification problem still leaves room for an insightful qualitative study of PIM. We complement previous research in presenting several diagnostic marks that retain preservation potential and may be used to suggest osseous, rather than lithic, projectile technology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12520-024-01944-3.

Investigating Underfloor and Between Floor Deposits in Standing Buildings in Colonial Australia

Archaeological deposits build up inside standing buildings both under and between floors and these have the potential to provide considerable information about human behavior in the past. Under and between floor spaces provide a unique depositional environment that allow the survival of rare and fragile organic materials that typically do not survive in other archaeological contexts, including paper, cardboard, fabric and other fibres, seeds, leather, and human hair and skin cells. However, they require a clear understanding of depositional processes to allow their interpretation. Experimental archaeology was conducted to understand the process of artifact deposition and the interpretation of underfloor deposits in twelve standing buildings in Western Australia. Floors were built and a range of artifacts swept across them to determine how artifacts travelled across floorboards or fell through gaps between boards. Size, shape, and angularity of artifacts were key determinants of the likelihood of deposition. Sweeping activity makes it more likely that material will be deposited around the margins of rooms, and particularly, to either side of doorways. Underfloor deposits excavated from two specific Western Australian buildings, Ellensbrook Homestead, and the York Residency Museum, are interpreted based on the results of these experiments.

Isolation and Characterization of Live Yeast Cells from Ancient Clay Vessels

Ancient fermented food has been studied mainly based on residue analysis and recipes and reconstruction attempts were performed using modern domesticated yeast. Furthermore, microorganisms which participated in fermentation were studied using ancient-DNA techniques. In a recent paper, we presented a novel approach based on the hypothesis that enriched yeast populations in fermented beverages could have become the dominant species in storage vessels and their descendants could be isolated and studied today. Here we present a pipeline for isolation of yeast from clay vessels uncovered in archeological sites and transferred to the microbiology lab where they can be isolated and characterized. This method opens new avenues for experimental archeology and enables attempts to recreate ancient food and beverages using the original microorganisms.

Hominin fire use in the Okote member at Koobi Fora, Kenya: New evidence for the old debate

Hominin fire use in the early Pleistocene has been debated since the early 1970s when consolidated reddened sediment patches were identified at FxJj20 East and Main, Koobi Fora, Kenya. Since then, researchers have argued for evidence of early Pleistocene fire use at a handful of archaeological sites with evidence of combustion. Some argue that morphological evidence of early Homo erectus fossils indicates a dietary shift to higher quality food sources, which could be achieved by cooking. Others contend that fire use does not become a regular behavior until later, in the middle Pleistocene, when archaeological sites begin to show regular evidence for fire use. An early date for hominin control of fire would help to explain the grade changes seen with the appearance of H. erectus, while a later date would mean that fire would have had little influence on the early development of the lineage. Early hominins would have encountered fire regularly on the landscape, increasing the possibility of hominins interacting with and habituating to natural landscape fire. Only a detailed understanding of the patterns of controlled and natural fires can lead to understanding of early hominin fire use. We present new work on the evidence of fire at the FxJj20 Site complex in Koobi Fora, dated to 1.5 Ma. We highlight evidence of burning found on site through Fourier Transform Infrared spectrometry, and describe ongoing work to investigate the association of hominin behavior and fire evidence. We present data supporting the hypothesis that the site is undisturbed and discuss spatial relationships showing burned material associated with non-burned material. We present data on a type of stone fragment, the Thermal Curve Fragment (TCF), which is indicative of knapped material being exposed to high heat. Finally, we suggest future directions on the topic of fire in the early Pleistocene.

Understanding stone tool-making skill acquisition: Experimental methods and evolutionary implications

Despite its theoretical importance, the process of stone tool-making skill acquisition remains understudied and poorly understood. The challenges and costs of skill learning constitute an oft-neglected factor in the evaluation of alternative adaptive strategies and a potential source of bias in cultural transmission. Similarly, theory and data indicate that the most salient neural and cognitive demands of stone tool-making should occur during learning rather than expert performance. Unfortunately, the behavioral complexity and extensive learning requirements that make stone knapping skill acquisition an interesting object of study are the very features that make it so challenging to investigate experimentally. Here we present results from a multidisciplinary study of Late Acheulean handaxe-making skill acquisition involving twenty-six naïve participants and up to 90 hours training over several months, accompanied by a battery of psychometric, behavioral, and neuroimaging assessments. In this initial report, we derive a robust quantitative skill metric for the experimental handaxes using machine learning algorithms, reconstruct a group-level learning curve, and explore sources of individual variation in learning outcomes. Results identify particular cognitive targets of selection on the efficiency or reliability of tool-making skill acquisition, quantify learning costs, highlight the likely importance of social support, motivation, persistence, and self-control in knapping skill acquisition, and illustrate methods for reliably reconstructing ancient learning processes from archaeological evidence.

Testing accuracy in 2D and 3D geometric morphometric methods for cut mark identification and classification

The analysis of bone surface modifications (BSMs) is a prominent part of paleoanthropological studies, namely taphonomic research. Behavioral interpretations of the fossil record hinge strongly upon correct assessment of BSMs. With the significant impact of microscopic analysis to the study of BSMs, multiple authors have discussed the reliability of these technological improvements for gaining resolution in BSM discrimination. While a certain optimism is present, some important questions are ignored and others overemphasized without appropriate empirical support. This specifically affects the study of cut marks. A diversity of geometric morphometric approaches applied to the study of cut marks have resulted in the coexistence (and competition) of different 2D and 3D methods. The present work builds upon the foundation of experiments presented by Maté-González et al. (2015), Courtenay et al. (2017) and Otárola-Castillo et al. (2018) to contrast for the first time 2D and 3D methods in their resolution of cut mark interpretation and classification. The results presented here show that both approaches are equally valid and that the use of sophisticated 3D methods do not contribute to an improvement in accuracy.

Functionality and Morphology: Identifying Si Agricultural Tools from Among Hemudu Scapular Implements in Eastern China

Most Chinese archaeologists assume that the scapular implements used in the Hemudu culture in eastern China (7000-5000 BP) were the si agricultural implements (tools for breaking ground and turning soils over to assist in seeding) recorded in ancient Chinese literatures and, accordingly, assume the Hemudu culture was a farming society. However, ethnographic and historical literatures worldwide have suggested inconclusive functions for similar implements. We conducted a range of experiments under realistic conditions, including hide and plant processing and earth-working, followed by use-wear analysis, to identify the functions of the Hemudu scapular implements. The results suggest that no more than half of the implements were employed as si and that their penetrability and durability were rather limited. These findings help explain why Hemudu should not be labeled as a farming society. Through experimentation and use-wear analysis, we produced relatively large datasets that make a significant contribution to the identification of soil-derived wear patterns on bone tools. We also included quantitative measurements of soil properties to ensure similarities in use contexts between our experimental and archaeological analogies in order to reach reliable functional identifications. Our approaches and results, therefore, provided a solid base for re-evaluating previous research as well as building a standardized database of scientific value for future evaluation and adjustment, even if that future research is done in isolation and in different soil contexts.