ABSTRACT This study tests predictions of the Economic Defensibility Model (EDM) regarding the relationship between resource density and distribution, as well as signaling behavior among Late Pleistocene foragers. The EDM proposes that territorial signaling intensifies when resources are dense and predictable, as the benefits of broadcasting group membership and maintaining alliances outweigh signaling costs. We evaluate this model using data from Boomplaas Cave, South Africa, with deposits spanning the Last Glacial Maximum (29–19 ka) to the early Last Glacial–Interglacial Transition (19–14 ka). We examine proxies of signaling—ochre procurement and ostrich eggshell beads—relative to measures of resource density and predictability inferred from the site's faunal data. Results reveal a strong positive correlation between non‐local ochre use and ostrich eggshell bead production, while ostrich eggshell bead densities are negatively correlated with gregarious grazer abundance. Contrary to EDM predictions, explicit signaling and cultural material social mediation behaviors expand when dense, predictable prey decline. These findings suggest that signaling technologies at Boomplaas were not mechanisms of territorial defense over defensible resources but strategies for maintaining social networks and mitigating subsistence risk under reduced ecological productivity. The intensification of bead production and the use of non‐local ochre reflect social boundary defense and alliance‐building strategies during periods of resource unpredictability. By integrating behavioral ecology with costly signaling theory, this study highlights the adaptive role of material signaling in buffering risk and sustaining social cohesion during climatic and environmental transitions in Late Pleistocene southern Africa.

Engraved ochres and ostrich eggshells from the South African Blombos Cave and Diepkloof Rock Shelter are among the earliest expressions of human symbolic behavior. They appear to document a continuous practice of mark-making across ∼40,000 years. During this time, the engraved markings change from simpler, unstructured patterns to more complex markings such as cross-hatchings. Previous work examining the cognitive implications of these changes concluded that the engravings were likely used as decorations and may have served as group identity markers, but not as denotational symbols. To inform discussions of the emergence of symbolic behavior, we conducted a two-part experimental study inspired by these engravings and based on the assumption that artifact use will motivate incremental adaptive refinements. Part 1 combined a delayed reproduction task with a transmission chain design to simulate an enduring mark-making practice. Eleven transmission chains were seeded with four drawings derived from the early Blombos and Diepkloof engravings and reproduced over eight generations. Transmission chain drawings showed a tendency to become increasingly regular, organized, and symmetric. Part 2 subjected a sample of the transmission chain drawings to a suite of psychophysical experiments to assess the cognitive implications of the accumulated structural changes. We found that the drawings became easier to discriminate, looked more like they had been intentionally made, and became easier to remember and reproduce, but there was no evidence of a systematic change in saliency or stylistic properties. Finally, we compared the results from the transmission chains with a similar analysis of the drawings derived from the original engravings. Although we observe interesting qualitative similarities between the original engravings and the experimental drawings, our findings suggest that cognitive biases and working memory constraints are not sufficient to generate the patterns observed in the archaeological record, highlighting the significance of social and functional contexts in shaping early symbolic artifacts. By integrating archaeological and experimental research, we can better inform inferences on sparse records of early symbolic behavior. Our study thus leads to a broader consideration of the role, strengths, and potential limitations of the transmission chain approach in analyzing trajectories of early symbolic behavior.

ABSTRACT In southern Africa, worked bone and shell have been found in both forager and farmer contexts dated to the last two thousand years. Foragers and farmers worked animal bone and shell into tools and personal objects, yet the range of tool types and possible activities in which the tools were used remains poorly understood. This paper presents the results of a morphological and use-trace analysis of 287 bone, shell and ostrich eggshell objects from three roughly contemporaneous forager and farmer sites in the Limpopo Valley of South Africa, namely Little Muck Shelter, Schroda and Pont Drift. It describes and contextualises the worked bone and shell forms, the production techniques and technology used and evidence regarding tool use. Objects present at both farmer and forager sites include arrow components, awls and needles and seem to have been used in similar activities, such as hunting, skin/hide working and basketry. Intensification of activities that incorporated bone technology at farmer sites can be linked to expanding local and long-distance trade activities.

Does exposure to heat alter stable isotopes in ostrich eggshell? A controlled experiment and analysis

The advent of environmental awareness and the need for circular economies have led to huge efforts towards using sustainable materials. Packaging plastics are the biggest source of mismanaged waste. Biopolymers are expected to serve as alternatives, and polylactic acid (PLA) is a promising candidate. However, they still have some performance drawbacks that hinder their total domination of the plastic market. Several strategies to improve their performance include blending with fibers and fillers to produce biopolymer based composites. One such important filler is calcium carbonate (CaCO3), which is sourced from mining a sedimentary rock, a non-renewable resource. Aviculture waste valorisation of eggshells could serve as a suitable source of organic CaCO3. In this study, the biggest and calcite rich ostrich eggshells were proposed as a sustainable filler material for PLA biopolymer matrix. PLA was loaded with different weights of ostrich eggshell waste powder (OES) and subjected to characterisation tests, including mechanical, thermal, and food contact migration testing. 5wt% OES loading resulted in the optimum tensile strength. The composites had remarkably reduced water vapour permeability, and overall migration levels were far below the overall migration limit (10 mg/dm2). The results of this study primarily suggested potential for PLA/OES biocomposites application in food packaging.

Luminescence and radiocarbon dating the Naisiusiu Beds type section and timing of the Middle Stone Age/Later Stone Age transition at Olduvai Gorge, Tanzania.

Research Type: Level 5 - Case report, Expert opinion, Personal observation Introduction/Purpose: Tendon injuries pose substantial medical, social, and economic challenges worldwide. Despite advancements in repair techniques, outcomes remain suboptimal due to poor tissue quality and function. Tissue engineering presents a promising solution, with biocompatible scaffolds playing a key role in regeneration. Ostrich eggshell membrane (ESM), distinguished by its organized calcite crystal structure and superior mechanical properties compared to other avian membranes, has emerged as a potential natural scaffold. When combined with platelet-rich plasma (PRP), known for its regenerative benefits, ESM offers a promising approach to enhancing tendon repair. Methods: Ostrich ESM was prepared from pathogen-free ostrich eggs, sterilized with UV radiation and prepared in desired dimensions before implantation (1.5 x 1 cm). High-resolution scanning electron microscopy (HRSEM) was utilized to visualize the sample morphology and fiber bonding. In vitro biocompatibility was assessed using the MTT assay and DAPI staining, while in vivo biocompatibility was evaluated in a rat model. For the in vivo Achilles tendinopathy assay, rats were divided into groups and subjected to AT rupture followed by treatment with ESM, PRP, or a combination. SEM was employed to evaluate tendon morphology, and real-time PCR was conducted to analyze gene expression levels. Results: The in vivo assay indicated that the ESM scaffold was safe for an extended period of 8 weeks, showing no signs of inflammation based on histopathological analysis. In the Achilles tendon rupture model, combining ESM with PRP enhanced tendon healing after 14 weeks post-surgery. Histopathological, morphological, and mechanical assessments confirmed this finding by comparing tendon tissues to normal tendons, untreated tendinopathy, and injured tendons treated with the ESM scaffold. Gene expression analysis revealed significantly increased expression of Col1a1, Col3a1, bFGF, Scleraxis (Scx), and tenomodulin in the ESM-PRP groups. Conclusion: The combination of Ostrich ESM with PRP significantly enhances AT repair and is a biocompatible scaffold for the application in living organisms.

Taphonomic considerations for identifying ochre residues on ostrich eggshell

Ostrich eggshell bead size variation: The impacts of material and technology on bead diameter

Detailed analysis of particle size, morphology, elemental composition, crystalline structure, and thermal degradation behavior reveals significant differences between ratite and crocodile eggshells, showing their unique environmental adaptations and biological functions. Ratite eggshells, characterized by smaller particle sizes, present lower thermal degradation and are more suitable for applications requiring flexibility and resilience. In contrast, crocodilian eggshells have more extensive and denser particles, giving them a more uniform structure and therefore contributing to their higher thermal stability and mechanical strength. The variation in activation energy profiles between different parts of the eggshells indicates the complexity of their degradation processes. In this regard, ostrich eggshell presents more complicated, multistage thermal degradation patterns, and may be suitable for layered thermal stability applications. In contrast, the uniform degradation behavior of emu eggshells suggests its utility in systems where consistent thermal performance is essential. Similarly, the stable and predictable degradation profiles of river and swamp crocodile eggshells make them ideal candidates for environments requiring high durability and resistance to thermal cycling. This research highlights the natural design of eggshells and provides valuable guidance for the development of biomimetic materials. By mimicking the structural and thermal properties of these eggshells, it would be useful to create thermally stable and mechanical materials suitable for a wide range of industrial and biomedical applications.

Tendon injuries present significant medical, social, and economic challenges globally. Despite advancements in tendon injury repair techniques, outcomes remain suboptimal due to inferior tissue quality and functionality. Tissue engineering offers a promising avenue for tendon regeneration, with biocompatible scaffolds playing a crucial role. Ostrich eggshell membrane (ESM), characterized by a strong preferential orientation of calcite crystals, forms a semipermeable polymer network with excellent mechanical properties compared to membranes from other bird species, emerging as a potential natural scaffold candidate. Coupled with platelet-rich plasma (PRP), known for its regenerative properties, ESM holds promise for improving tendon repair. This study aims to evaluate the biocompatibility and efficacy of an ESM-PRP scaffold in treating Achilles tendon ruptures, employing in vitro and in vivo assessments to gauge its potential in tendon regeneration in living organisms. Ostrich ESM was prepared from pathogen-free ostrich eggs, sterilized with UV radiation and prepared in desired dimensions before implantation (1.5 × 1 cm). High-resolution scanning electron microscopy (HRSEM) was utilized to visualize the sample morphology and fiber bonding. In vitro biocompatibility was assessed using the MTT assay and DAPI staining, while in vivo biocompatibility was evaluated in a rat model. For the in vivo Achilles tendinopathy assay, rats were divided into groups and subjected to AT rupture followed by treatment with ESM, PRP, or a combination. SEM was employed to evaluate tendon morphology, and real-time PCR was conducted to analyze gene expression levels. The in vivo assay indicated that the ESM scaffold was safe for an extended period of 8 weeks, showing no signs of inflammation based on histopathological analysis. In the Achilles tendon rupture model, combining ESM with PRP enhanced tendon healing after 14 weeks post-surgery. This finding was supported by histopathological, morphological, and mechanical evaluations of tendon tissues compared to normal tendons, untreated tendinopathy, and injured tendons treated with the ESM scaffold. Gene expression analysis revealed significantly increased expression of Col1a1, Col3a1, bFGF, Scleraxis (Scx), and tenomodulin in the ESM-PRP groups. The findings of our study demonstrate that the combination of Ostrich ESM with PRP significantly enhances AT repair and is a biocompatible scaffold for the application in living organisms.

Assessing ostrich eggshell bead production at little muck shelter: Experimental production to test efficiency and success rates of pathway 1 and 2

Ostrich eggs have recently attracted interest as an alternative model in preclinical nuclear medicine imaging. The ability to be used in clinical PET/CT (positron emission tomography/computed tomography) systems and their ethical profile are advantageous over conventional rodent models and other avian systems. Nevertheless, concerns regarding radiation exposure during repeated CT (computed tomography) imaging of developing embryos remain inadequately addressed. This study aimed to characterize the attenuation impact of eggshells in ostrich eggs and to evaluate the potential for organ-specific dose assessment. A representative ostrich egg was selected from a cohort of 168 eggs and used to construct a dimensionally matched 3D-printed phantom. Organ weights of 83 embryos were documented on development day (DD) 37 to provide a basis for future organ-level dosimetric modeling. Thermoluminescence dosimeters (TLDs) were positioned along the z-axis within both the egg and phantom, and CT dose distributions were measured using a clinical PET/CT system. The mean absorbed dose in the real egg was 16.3 ± 2.0% lower than in the phantom, attributable to radiation attenuation by the 1.89 ± 0.12 mm thick eggshell. CTDI (computed tomography dose index) values remained stable across developmental stages (DD 0–37). Our findings confirm that the ostrich eggshell exerts a significant shielding effect during CT imaging. While ostrich eggs are suitable for serial in-ovo imaging, embryo positioning remains a major limitation for precise dosimetry. Organ weight data enable potential use of AI (artificial intelligence)-based modeling to improve spatial dosimetry accuracy. This study provides essential groundwork for dose optimization and radioprotection in preclinical imaging protocols using ostrich eggs.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11307-025-02065-6.

Background: The material most frequently employed in the dental industry is polymethyl methacrylate (PMMA). Temporary dental restorations, including those for complex indications such as implants or large-span bridges, are manufactured using this material. However, its numerous limitations render it unsuitable for application in all situations. Consequently, individuals utilizing removable prostheses must be concerned regarding the potential for fracture. The purpose of this study: examined the effects of various particle sizes of 5% hydroxyapatite (which was prepared from ostrich eggshell powder) on the roughness and compressive strength of heat-cured acrylic resin. Materials and Methods: A total of 28 cylindrical samples composed of pink heat-treated acrylic resin were fabricated and subsequently categorized into four experimental groups; Group A (Control without any additive), Group B (Particle size 80µm), Group C (Particle size 70 µm), and Group D (Particles Size 50 µm). Each group consisted of seven samples categorized according to the varying sizes of hydroxyapatite particles. The test groups homogenously blended at a weight percentage of 5% of ostrich eggshell powder. Subsequently, an assessment was conducted to determine the collective compressive strength and surface roughness of this groups. Result: The results of the investigation showed significant variations in compressive strength for group B (107±3.742 MPA), group C (103.43±5.192 MPA), and group D (98.43±7.323 MPA) concerning the different sizes of hydroxyapatite particles compared to group A (74±4.163 MPA). While there was a significant increase in surface roughness for groups B (3.22±0.014), C (2.41±0.018), and D (2.36±0.077) compared to group A (1.451±0.073). Conclusion: Varying the particle size of hydroxyapatite added to the thermosetting acrylic resin (80μm, 70μm, and 50μm) increases both the material's compressive strength and surface roughness.

The analysis of the Grotta Capéletti pastoral assemblage shows a significant transformation in the use of hard animal materials, mirroring changes seen at other Neolithic Capsian sites. This shift, affecting all material culture, includes the introduction of new lithic tools —such as concave and tanged arrowheads—alongside traditional Epipalaeolithic implements, indicating evolving hunting strategies. Ceramic vessels and new containers made from materials like tortoise shell and ostrich eggshell become common for food preparation. The lithic industry also moves toward producing larger, more expedient tools, replacing the earlier focus on bladelets. In the bone industry, there is a transition from small Epipalaeolithic tools to larger, thicker implements, with the first appearance of tools crafted from animal ribs and scapulae. These innovations, especially in the Rivière collection, highlight advanced technical skills and a strong link between bone and ceramic technologies, reflecting new subsistence strategies tied to animal domestication.

Ostrich eggshell beads: Hole drilling technology at Little Muck Shelter, South Africa

ABSTRACT Ostrich eggshell beads have been produced by African societies for over 50,000 years and are still used in East Africa and elsewhere, yet the only well-documented ethnographic record of their manufacture comes from San and Bakgalagadi communities in the Kalahari region of southern Africa. Even so, some aspects of their social significance have not been extensively explored. In particular, research on ostrich eggshell beads in southern Africa has historically focused largely on the use of beads in exchange contexts with less emphasis on their use in bodily adornment or the social contexts of manufacture and consumption. This paper reports on the production process and cultural significance of ostrich eggshell beads among the El Molo community of Marsabit County, Kenya. Undertaken as part of the British Museum’s Endangered Materials Knowledge Program (EMKP), this project used unstructured interviews, participatory videos, photography and note-taking to document the entire process of ostrich eggshell bead manufacture, including the collection of hammer stones (soit), the making of strings (arkat) for stringing the beads, the breaking of shells, shaping and rounding, stringing and the making of diverse beadwork items, including rumirumi, kukuti, karkato, lilim and rarak. The social significance of these various items is also reported. This study helps to preserve this knowledge and the continuation of the craft in the community, while also providing data for the enrichment of interpretations of ostrich eggshell beads from archaeological collections in the region, which have received inadequate research attention. The project represents the first detailed ethnographic work ever undertaken on ostrich eggshell beads in East Africa. The materials produced will be available on the EMKP open access online repository.

ABSTRACT Ostriches are peculiar birds and their strangeness has been recognised by southern African hunter-gatherers through multiple symbolic associations. Such qualities are likely to have been enhanced where people had access to beads made from their eggshell but did not have direct knowledge of the birds themselves. Southeastern southern Africa, encompassing the Maloti-Drakensberg Mountains, the eastern half of the Eastern Cape Province and much of KwaZulu-Natal is one such area. We review the unusual attributes and associations of ostriches and their eggshell before briefly summarising previous work that has used strontium isotope analysis to investigate past bead exchange networks in this region. Because bead size can be controlled and patently varies through time and space, we then employ it as another potential indicator of the existence and spatial extent of past social networks. Having critically considered previous efforts in this field, we report on our work to build the largest sample of such data yet obtained in southern Africa and compare our preliminary results with other signals of interaction between precolonial hunter-gatherer and (where applicable) agropastoralist communities.

ABSTRACT Southern Africa’s Cape Floristic Region (CFR) has long been a focus of research aiming to integrate relationships between Quaternary climate dynamics, terrestrial ecosystem change, and modern human origins. Pleistocene mammal assemblages play a key role in this research. However, a lack of securely dated sites, especially from the western coastal plains of the CFR, has posed a challenge for understanding faunal communities and their connection to Pleistocene climate dynamics. Here, we present the systematic paleontology and paleoecological analysis of the large mammals from Besaansklip, a well-dated late glacial hyena den (∼16,000 years ago) from the west coast of the CFR. We identified >400 mammalian specimens from Besaansklip, which we use to infer past climate and terrestrial environments. Like other Pleistocene fossil assemblages in the region, Besaansklip has a high abundance and diversity of water-dependent grazers, many of which are extinct (e.g., Equus capensis and Syncerus antiquus) or extirpated (e.g., Connochaetes gnou). Stable carbon isotope analysis of ostrich eggshells from Besaansklip suggests a lack of C4 grasses, implying a cool growing season and dominance of winter rainfall. These findings reinforce previous models suggesting that glacial phases of the Pleistocene were associated with increased moisture availability and productivity, and perhaps an expansion of grassy vegetation in the southwestern Cape.

Fiber technology, crucial to human societies for millennia, encompasses cordage and textiles. The development of fiber crops and the production of fiber-based clothing are significant components of the Neolithic Revolution. Despite China being an independent center for agriculture, the role of fiber technology in this context remains largely unexplored. In this project, we employed a comprehensive approach that combines microfossil analysis and use-wear examinations to study tools from the Peiligang site in North China. This site uniquely spans the Upper Paleolithic and early Neolithic periods, offering an ideal setting for investigating the evolution of fiber production. Our results reveal that some Paleolithic blades and scrapers were associated with fiber production, which coincided with ostrich eggshell beads and hematite during the cold and dry Last Glacial Maximum period. Responding to climatic fluctuations, fiber production played a significant role in subsistence and ritual activities. In the early Neolithic, advanced fiber production is evident. Two adjacent burials yield tools and microfossil remains representing a toolkit for fiber and possible textile production, including harvesting, retting, pounding, scraping, and sewing. Fibers recovered from human bones provide potential evidence of textile production and use. Dyeing with blue, black, and red colorants was common for textiles, cordages, and strings. These grave goods suggest the involvement of the deceased in craft production with bast fibers, possibly embodying the earliest specialization in fiber craft 8000 years ago in Neolithic China.