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The six 3D printed replica tools. Original lithics were knapped and scanned by CS in preparation for 3D printing. Example photos were taken by SH. Scale = 3 cm
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Evaluating error that arises through the aggregation of data recorded by multiple observers is a key consideration in many metric and geometric morphometric analyses of stone tool shape. One of the most common approaches involves the convergence of observers for repeat trails on the same set of artefacts: however, this is logistically and financial...
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The taxonomic status of the zooplanktivorous cichlids Copadichromis mloto and C. virginalis has been confused since their original descriptions by lles in 1960. Whilst two forms of C. virginalis, 'Kaduna' and 'Kajose', were distinguished in the type material, C. mloto has not been positively identified since its original description. H...
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... Comparative research and replicability are key aspects in science and are becoming increasingly relevant for lithic analyses in the 21st century (e.g., 29,43 ). In conjunction with recent studies on the replicability of individual attributes on flakes 30,44,45 and considering that flakes are the most frequent and common lithic products, FLEXDIST allows for the systematic comparison of flake assemblages across and within sites, regions and even across continents if comparable attribute definitions and recording procedures are followed. These attribute data already exist for many Palaeolithic sites. ...
... allowing for easy access, method replicability and potential improvements. These are essential features for strengthening open science and collaborative approaches among researchers in archaeology and lithic analysis 29,45,[57][58][59][60][61] . To evaluate the wider applicability, impact and limits of FLEXDIST, additional studies will need to test the method on flake assemblages from other site sequences with more complex patterns of cultural change, different periods, site function, technological backgrounds and raw materials. ...
... Unretouched blades and bladelets could also be included in future studies, which may result in even clearer patterns of variation than identified here due to their marked shape differences. Limits to such studies lie in systematically recording multi-scale attribute data on flakes and the replicability of such observations when multiple analysts are involved 30,44,45 . 21st century lithic analysis attests to a shift towards recording more replicable quantitative data, pursuing collaborative research and applying multivariate statistics to large (open) datasets, an approach which we follow here as well. ...
Lithic artefacts provide the principal means to study cultural change in the deep human past. Tools and cores have been the focus of much prior research based on their perceived information content and cultural relevance. Unretouched flakes rarely attract comparable attention in archaeological studies, despite being the most abundant assemblage elements and featuring prominently in ethnographic and experimental work. Here, we examine the potential of flake morphology for tracing cultural change utilising 4,512 flakes, each characterised by 16 standard mixed-scale attributes, from a well-documented cultural sequence at the Middle Stone Age site of Sibhudu, South Africa. We quantified multivariate similarities among flakes using FLEXDIST, a highly versatile method capable of handling mixed, correlated, incomplete, and high-dimensional data. Our findings reveal a significant gradual change in flake morphology that aligns with the documented cultural succession at Sibhudu. Furthermore, our analysis provides new insights into the patterning of variability throughout the studied sequence. The demonstrated potential of flakes to track cultural change opens up additional avenues for comparative research due to their ubiquity, the availability of commonly recorded attributes, and especially in the absence of cores or tools. FLEXDIST, with its versatile applicability to complex lithic datasets, holds particular promise in this regard.
... The intraclass correlation coefficient (ICC) was computed (with PCA scores in the outlines approach and with Procrustes coordinates in the landmarks approach) using the "psych" R package (Revelle 2021) to assess the agreement between the two datasets. The ICC compares the variability within repeat measurements while contrasting variability between groups of measurements (Timbrell et al. 2022). ...
In this study, we compared the efficacy of geometric morphometric techniques, including outlines and landmark-based approaches, to support the differentiation of Trichodina bellottii from three co-occurring killifish species. Both methods were able to differentiate trichodinids from different host species. However, discriminat analyses and MANOVA results based on landmarks had greater accuracy possibly because these analyses only provide information on certain points defined by the researcher, while the analyses based on outlines take into account points with less taxonomic information.
... Von Cramon-Taubadel et al., 2007;Kaufman and Rosenthal, 2009;Fruciano, 2016;Robinson and Terhune, 2017;Verheyen et al., 2018), 14 C dating (e.g. Scott et al., 2022), and is also recognized, on a smaller scale, in archaeology (Fisch, 1978;Newcomer et al., 1986;Gobalet, 2001;Lyman and VanPool, 2009;Shahack-Gross, 2016;Skals et al., 2018;Timbrell et al., 2022). Although the issue of possible inter-and intra-observer variation affecting the accuracy and repeatability of morphometric studies is recognized in archaeobotany (Jacomet, 2013;Steiner et al., 2015, Evin et al., 2020Antolin, 2022;Roushannafas et al., 2023) and phytolith analysis (Ball et al., 2016b(Ball et al., , 2017Evett and Cuthrell, 2016;Díez-Pastor et al., 2020;Out, 2020), this variation has not yet been studied systematically in phytolith morphometry. ...
Background: Archaeobotanists and palaeoecologists extensively use geometric morphometrics to identify plant opal phytoliths. Particularly when applied to assemblages of phytoliths from concentrations retrieved from closed contexts, morphometric data from archaeological phytoliths compared with similar data from reference material may allow taxonomic attribution. Observer variation is one aspect of phytolith morphometry that has received little attention but may be an important source of error, and hence cause of potential misidentification of plant remains.
Scope: To investigate inter- and intra-observer variation in phytolith morphometry, eight researchers (observers) from different laboratories measured 50 samples each from three phytolith morphotypes, Bilobate, Bulliform flabellate and Elongate dendritic, three times, under the auspices of the International Committee for Phytolith Morphometrics (ICPM).
Methods: Data for 17 size and shape variables were collected for each phytolith by manually digitising a phytolith outline (mask) from a photograph, followed by measurement of the mask with open-source morphometric software.
Key results: Inter-observer variation ranged from 0 to 23% difference from the mean of all observers. Intra-observer variation ranged from 0 to 9% difference from the mean of individual observers per week. Inter- and intra-observer variation was generally higher among inexperienced researchers.
Conclusions: Scaling errors were a major cause of variation and occurred more with less experienced researchers, which is likely related to familiarity with data collection. The results indicate that inter- and intra-observer variation can be substantially reduced by providing clear instructions for and training with the equipment, photo capturing, software, data collection and data cleaning. In this paper, the ICPM provides recommendations to minimise variation.
Advances in automatic data collection may eventually reduce inter- and intra-observer variation, but until this is common practice, the ICPM recommends that phytolith morphometric analyses adhere to standardised guidelines to assure that measured phytolith variables are accurate, consistent and comparable between different researchers and laboratories.
... Alternatively, the use of quantitative measurements allows continuous morphological variation among artefacts to be described and compared on an objective numerical scale. While a quantitative approach itself is not free of inter-observer variation (Pargeter et al., 2023a), measurement error can be more easily gauged and managed through explicit definitions and protocols (Gnaden and Holdaway, 2000;Timbrell et al., 2022). Traditionally, quantification in stone artefact analysis tends to be limited to linear metric (e.g., length, width, thickness) and simple meristic (i.e., scar count). ...
In stone artefact studies, researchers often rely on qualitative classifications to describe flake scar arrangements on cores. While this approach provides a broad overview of core reduction patterns, its application can be ambiguous due to the three-dimensional complexities of core geometry and the subjective nature of qualitative classifications, making it challenging to objectively compare flake scar patterning across different analytical settings. In this study, we present a new approach to quantify one aspect of flake scar arrangement on cores: the three-dimensional orientation of core scar negatives. Using standardised digital and experimentally flintknapped cores, we demonstrate that statistical techniques from fabric analysis can quantitatively characterise the scar orientation profile of cores. Importantly, this method is able to reveal variations in the flake scar arrangements of informal cores, such as multiplatform cores. When applied to a sample of multiplatform cores from the Homo floresiensis type-site of Liang Bua in Indonesia, we identify differences in flake scar orientation between cores made by Homo floresiensis and those manufactured by modern humans who utilised the site after the disappearance of the extinct hominin. This finding suggests a possible divergence in stone knapping practices between the two hominin taxa at Liang Bua. Overall, our research provides a new quantitative approach to gain new insights into hominin technological behaviour through stone artefact analysis. It also highlights the potential of 3D analysis for advancing the field of archaeological lithic research.
... To study the structure of eastern African MSA point variability, artefact samples were accessed via a collaborative data collection framework (Timbrell 2022;Timbrell et al. 2022c) with the National Museums of Kenya and the National Museum of Ethiopia. Table 1, Figure 1 and Supplementary Figure S1 describes the sample, which includes artefacts from both dated and undated layers, with date ranges rounded to the nearest 1000 years. ...
... We also performed two-dimensional geometric morphometrics on the photographs of the points taken via collaborative data collection as outlined and validated in Timbrell (2022) and Timbrell et al. (2022c). The protocols optimised the photographs for outline-based GMM, including the use of a scale and minimising of shadows around the object. ...
... Future research should address this compositional complexity. In sum, our work aligns with approaches to lithic tool shape and technological analyses that-especially if integrated with quantitative and replicable protocols-promise an understanding of material culture change beyond typological categories and traditionally named units [195][196][197][198][199]. ...
Archaeological systematics, together with spatial and chronological information, are commonly used to infer cultural evolutionary dynamics in the past. For the study of the Palaeolithic, and particularly the European Final Palaeolithic and earliest Mesolithic, proposed changes in material culture are often interpreted as reflecting historical processes, migration, or cultural adaptation to climate change and resource availability. Yet, cultural taxonomic practice is known to be variable across research history and academic traditions, and few large-scale replicable analyses across such traditions have been undertaken. Drawing on recent developments in computational archaeology, we here present a data-driven assessment of the existing Final Palaeolithic/earliest Mesolithic cultural taxonomy in Europe. Our dataset consists of a large expert-sourced compendium of key sites, lithic toolkit composition, blade and bladelet production technology, as well as lithic armatures. The dataset comprises 16 regions and 86 individually named archaeological taxa (‘cultures’), covering the period between ca. 15,000 and 11,000 years ago (cal BP). Using these data, we use geometric morphometric and multivariate statistical techniques to explore to what extent the dynamics observed in different lithic data domains (toolkits, technologies, armature shapes) correspond to each other and to the culture-historical relations of taxonomic units implied by traditional naming practice. Our analyses support the widespread conception that some dimensions of material culture became more diverse towards the end of the Pleistocene and the very beginning of the Holocene. At the same time, cultural taxonomic unit coherence and efficacy appear variable, leading us to explore potential biases introduced by regional research traditions, inter-analyst variation, and the role of disjunct macroevolutionary processes. In discussing the implications of these findings for narratives of cultural change and diversification across the Pleistocene-Holocene transition, we emphasize the increasing need for cooperative research and systematic archaeological analyses that reach across research traditions.
... To study the structure of eastern African MSA point variability, artefact samples were accessed via a collaborative data collection framework (Timbrell 2022;Timbrell et al. 2022c) with the National Museums of Kenya and the National Museum of Ethiopia. Table 1, Figure 1 and Supplementary Figure S1 describes the sample, which includes artefacts from both dated and undated layers, with date ranges rounded to the nearest 1000 years. ...
... We also performed two-dimensional geometric morphometrics on the photographs of the points taken via collaborative data collection as outlined and validated in Timbrell (2022) and Timbrell et al. (2022c). The protocols optimised the photographs for outline-based GMM, including the use of a scale and minimising of shadows around the object. ...
Stone points are one of the key features used to define the African Middle Stone Age (MSA). Regional patterns in their shape and size through time have been thought to reflect inter-group interactions and networks of populations and are used to define cultural phases within the MSA. However, eastern Africa does not have distinctive and widely applied chrono-stratigraphic point variants that divide its MSA record, which is often described as being highly variable. This paper presents a metric and geometric morphometric analysis of eastern African MSA points and evaluates potential drivers of variation in them in relation to null models of isolation by distance, time and environment. Approximately half of the shape variance in our sample can be explained by spatial, temporal and environmental differences, as well as by size, indicating a degree of demographic continuity through sustained cultural transmission. A portion of the remaining variance likely represents stylistic differences between assemblages, which are often the subject of interest in archaeological studies. The highly variable nature of the eastern African MSA may reflect the region’s refugial positioning within the continent, with point technology a flexible adaptive system that was dynamically employed across Africa during the MSA depending on varying social and ecological contexts, resulting in the appearance of both ‘generic’ and ‘specific’ tool forms at particular times and places.
RÉSUMÉ
Les pointes de pierre sont l’une des caractéristiques-clé utilisées pour définir l’Âge de Pierre Moyen africain (Middle Stone Age, MSA). Il a été proposé que les distributions régionales dans les forme et les grandeurs au cours du temps reflètent les interactions entre groupes et les réseaux de populations, et ces distributions sont utilisées pour définir les phases culturelles au sein du MSA. Cependant, l’Afrique de l’Est ne possède pas de variantes chrono-stratigraphiques dans les pointes qui soient distinctives et largement appliquées et qui segmentent les données du MSA. Du reste ce registre du MSA est souvent décrit comme étant très variable. Cet article présente une analyse morphométrique métrique et géométrique des pointes MSA d’Afrique de l’Est, et évalue les facteurs potentiels de leur variation par rapport aux modèles nuls d’isolement en fonction de la distance, du temps et de l’environnement. À peu près la moitié de la variance de forme dans notre échantillon peut s’expliquer par des différences spatiales, temporelles et environnementales, ainsi que par la grandeur, indiquant un degré de continuité démographique à travers une transmission culturelle soutenue. Une partie de la variance restante représente probablement des différences stylistiques entre assemblages, qui sont souvent un objet d’intérêt pour les études archéologiques. La nature très variable du MSA est-africain peut refléter un positionnement de la région en tant que refuge au sein du continent. La technologie des pointes représenterait un système adapt if flexible qui fut utilisé de manière dynamique à travers l’Afrique pendant le MSA en fonction de divers contextes sociaux et écologiques, entraînant l’apparition de formes d’outils ‘génériques’ et ‘spécifiques’ à des moments et des lieux particuliers.
... Furthermore, the 2D outline data derives from legacy sources and different production styles may impact accuracy 62 . Drawings and photos have, however, been shown to provide reliable information for geometric morphometric analysis 40,63 , lending confidence that these data can be used for comparative inter-regional analyses. Notably, the acquisition of additional outline data for lithic artefacts is straightforward, and we hope that users will complement the dataset 19 at hand with further specimens. ...
Comparative macro-archaeological investigations of the human deep past rely on the availability of unified, quality-checked datasets integrating different layers of observation. Information on the durable and ubiquitous record of Paleolithic stone artefacts and technological choices are especially pertinent to this endeavour. We here present a large expert-sourced collaborative dataset for the study of stone tool technology and artefact shape evolution across Europe between ~15.000 and 11.000 years before present. the dataset contains a compendium of key sites from the study period, and data on lithic technology and toolkit composition at the level of the cultural taxa represented by those sites. The dataset further encompasses 2D shapes of selected lithic artefact groups (armatures, endscrapers, and borers/perforators) shared between cultural taxa. These data offer novel possibilities to explore between-regional patterns of material culture change to reveal scale-dependent processes of long-term technological evolution in mobile hunter-gatherer societies at the end of the Pleistocene. Our dataset facilitates state-of-the-art quantitative analyses and showcases the benefits of collaborative data collation and synthesis.
... Based on its flexibility and relative affordability, multi-image photogrammetry has become an increasingly useful analytical tool within archaeology (Magnani et al. 2020) with Close-Range Photogrammetry being used for lithic analysis (e.g. Caricola et al. 2018;Porter et al. 2016;Porter 2019;Collins et al. 2019;Bennett 2021;Timbrell et al. 2022). ...
This paper will present initial results from excavations at Maritime Academy, Frindsbury which produced several handaxes, two of which can be classed as ‘giant handaxes’. Artefacts were recovered from fluvial deposits in the Medway Valley and are thought to date from the Marine Isotope Stage 9 interglacial. This paper will focus on the largest of these handaxes and will present metrical data for the artefact and initial comparison with similar artefacts from the British Palaeolithic.
... On their part, Way et al. (2022) analysed the increasing complexity of the industries of the MSA combining the use of GM and paleoenvironmental data. Several other studies during this last year alone, including the integration or GM with other analytical techniques (Moreno et al., 2022), different approaches to research protocols (Timbrell et al., 2022) or even analyses on bone arrowheads (Tsirintoulaki et al., 2023), are proof of the increasing use of the method. Finally, and to conclude this short review, there are essentially two ways to approach the Fourier analysis, either by using landmarks or by using outlines. ...
