Wood technology: a Glossary and Code for analysis of archaeological wood from stone tool cultures
Open glossary for wood technologiesRecommended by Ruth Blasco based on reviews by Laura Caruso Fermé, Oriol López-Bultó, Eva Francesca Martellotta and Paloma Vidal-Matutano
Wood is a widely available and versatile material, so it is not surprising that it has been a key resource throughout human history. However, it is more vulnerable to decomposition than other materials, and its direct use is only rarely recorded in prehistoric sites. Despite this, there are exceptions (e.g., [1-5]  and references therein), and indirect evidence of its use has been attested through use-wear analyses, residue analyses (e.g., ) and imprints on the ground (e.g., ). One interesting finding of note is that the technology required to make, for example, wooden spears was quite complex , leading some authors to propose that this type of tool production represented a cognitive leap for Pleistocene hominids . Other researchers, however, have proposed that the production process for wooden tools could have been much easier than is currently thought . Be that as it may, in recent years researchers have begun to approach wood remains systematically, developing analyses of natural and anthropogenic damage, often with the help of experimental reference samples.
In this work, the authors elaborate a comprehensive glossary as a first step towards the understanding of the use of wood for technological purposes in different times and places, as there is still a general gap in the established nomenclature. Thus, this glossary is a synthesis and standardisation of analytical terms for early wood technologies that includes clear definitions and descriptions of traces from stone tool-using cultures, to avoid confusion in ongoing and future studies of wood tools. For this, the authors have carried out a detailed search of the current literature to select appropriate terms associated with additional readings that provide a wide, state-of-the-art description of the field of wood technology.
An interesting point is that the glossary has been organised within a chaîne opératoire framework divided into categories including general terms and natural traces, and then complemented by an appendix of images. It is important to define the natural traces –understanding these as alterations caused by natural processes–because they can mask those modifications produced by other agents affecting both unmodified and modified wood before, during or after its human use.
In short, the work carried out by Milks et al.  is an excellent and complete assessment and vital to the technological approach to wooden artifacts from archaeological contexts and establishing a common point for a standardised nomenclature. One of its particular strengths is that the glossary is a preprint that will remain open during the coming years, so that other researchers can continue to make suggestions and refinements to improve the definitions, terms and citations within it.
 Oakley, K., Andrews, P., Keeley, L., Clark, J., 1977. A reappraisal of the Clacton spearpoint. Proceedings of the Prehistoric Society 43, 13-30. https://doi.org/10.1017/S0079497X00010343
 Thieme, H., 1997. Lower Palaeolithic hunting spears from Germany. Nature 385, 807-810. https://doi.org/10.1038/385807a0
 Schoch, W.H., Bigga, G., Böhner, U., Richter, P., Terberger, T., 2015. New insights on the wooden weapons from the Paleolithic site of Schöningen. Journal of Human Evolution 89, 214-225. https://doi.org/10.1016/j.jhevol.2015.08.004
 Aranguren, B., Revedin, A., Amico, N., Cavulli, F., Giachi, G., Grimaldi, S. et al., 2018. Wooden tools and fire technology in the early Neanderthal site of Poggetti Vecchi (Italy). Proceedings of the National Academy of Sciences. 115, 2054-2059. https://doi.org/10.1073/pnas.1716068115
 Rios-Garaizar, J., López-Bultó, O., Iriarte, E., Pérez-Garrido, C., Piqué, R., Aranburu, A., et al., 2018. A Middle Palaeolithic wooden digging stick from Aranbaltza III, Spain. PLoS ONE 13(3): e0195044. https://doi.org/10.1371/journal.pone.0195044
 Milks, A. G., Lehmann, J., Böhner, U., Leder, D., Koddenberg, T., Sietz, M., Vogel, M., Terberger, T., 2022,. Wood technology: a Glossary and Code for analysis of archaeological wood from stone tool cultures. Peer-reviewed and recommended by PCI Archaeology https://doi.org/10.31219/osf.io/x8m4j
 Nugent, S. 2006. Applying use-wear and residue analyses to digging sticks. Mem Qld Mus Cult Herit Ser 4, 89-105. https://search.informit.org/doi/10.3316/informit.890092331962439
 Allué, E., Cabanes, D., Solé, A., Sala, R., 2012. Hearth Functioning and Forest Resource Exploitation Based on the Archeobotanical Assemblage from Level J, in: i Roura E. (Ed.), High Resolution Archaeology and Neanderthal Behavior: Time and Space in Level J of Abric Romaní (Capellades, Spain). Springer Netherlands, Dordrecht, pp. 373-385. https://doi.org/10.1007/978-94-007-3922-2_9
 Ennos, A.R., Chan, T.L., 2016. "Fire hardening" spear wood does slightly harden it, but makes it much weaker and more brittle. Biology Letters 12. https://doi.org/10.1098/rsbl.2016.0174
 Haidle, M.N., 2009. How to think a simple spear?, in: de Beaune S.A., Coolidge F.L., Wynn T. (Eds.), Cognitive Archaeology and Human Evolution. Cambridge University Press, New York, pp. 57-73.
 Garofoli, D., 2015. A Radical Embodied Approach to Lower Palaeolithic Spear-making. Journal of Mind and Behavior 36, 1-26.
Archaeophenomics of ancient domestic plants and animals using geometric morphometrics : a review
Archaeophenomics: an up-and-coming field in bioarchaeologyRecommended by Anneke H. van Heteren based on reviews by Stefan Schlager and 1 anonymous reviewer
Anneke H. van Heteren based on reviews by Stefan Schlager and 1 anonymous reviewer
Phenomics is the analysis of high-dimensional phenotypic data . Phenomics research strategies are capable of linking genetic variation to phenotypic variation , but a genetic component is not absolutely necessary. The paper “Archaeophenomics of ancient domestic plants and animals using geometric morphometrics: a review” by Evin and colleagues  examines the use of geometric morphometrics in bioarchaeology and coins the term archaeophenomics. Archaeophenomics can be described as the large-scale phenotyping of ancient remains, and both addresses taxonomic identification, as well as infers spatio-temporal agrobiodiversity dynamics. It is a relatively new field in bioarchaeology with the first paper using this approach stemming from 2004. This study by Evin et al.  presents an excellent review and unquestionably demonstrates the potential of archaeophenomics.
The authors provide an exhaustive review specifically of bioarchaeological studies in international journals using geometric morphometrics to study archaeological remains of domestic species. Although geometric morphometrics lends itself well for archaeophenomics, readers should keep in mind that this is not the only method and other approaches might equally fall under archaeophenomics as long as high-dimensional phenotypic archaeological data are involved.
Distinguishing archaeophenomics from phenomics is important because of a critical difference. Archaeological remains are often altered by taphonomical processes. As such data may not be as complete as when working with modern specimens. Although this poses difficulties, morphometric analyses can usually still be performed as long as the structures presenting the relevant geometrical features are present. Even fragmented remains can be studied with a restricted version of the original landmarking/measurement protocol.
Evin et al.  define archaeophenomics as “phenomics of the past”. This is only partly correct. It can be deduced from their review that they really mean phenomics of our (human) past. This leaves a gap for phenomics of the non-human past, for which I suggest the term palaeophenomics.
 Jin, L. (2021). Welcome to the Phenomics Journal. Phenomics, 1, 1–2. https://doi.org/10.1007/s43657-020-00009-4.
 Bilder, R.M., Sabb, F.W., Cannon, T.D., London, E.D., Jentsch, J.D., Stott Parker, D., Poldrack, R.A., Evans, C., Freimer, N.B. (2009). Phenomics: the systematic study of phenotypes on a genome-wide scale. Neuroscience, 164(1), 30-42. https://doi.org/10.1016/j.neuroscience.2009.01.027
 Evin, A., Bouby, L., Bonhomme, V., Jeanty, A., Jeanjean, M., Terral., J.-F. (2022). Archaeophenomics of ancient domestic plants and animals using geometric morphometrics: a review. Peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.31219/osf.io/skeu5
Tektite geoarchaeology in mainland Southeast Asia
Tektites as chronological markers: after careful geoarchaeological validation only!Recommended by Alain Queffelec and Shanti Pappu based on reviews by Sheila Mishra, Mike Morley, Toshihiro Tada and 1 anonymous reviewer
Tektites, a naturally occurring glass produced by major cosmic impacts and ejected at long distances, are known from five impacts worldwide . The presence of this impact-generated glass, which can be dated in the same way as a volcanic rock, has been used to date archaeological sites in several regions of the world. This paper by Marwick and colleagues  reviews and adds new data on the use and misuse of this specific material as a chronological marker in Australia, East and Southeast Asia, where an impact dated to 0.78 Ma created and widely distributed tektites. This material, found in archaeological excavations in China, Laos, Thaïland, Australia, Borneo, and Vietnam, has been used to date layers containing lithic artifacts, sometimes creating a strong debate about the antiquity of the occupation and lithic production in certain regions.
The review of existing data shows that geomorphological data and stratigraphic integrity can be questioned at many sites that have yielded tektites. The new data provided by this paper for five archaeological sites located in Vietnam confirm that many deposits containing tektites are indeed lag deposits and that these artifacts, thus in secondary position, cannot be considered to date the layer. This study also emphasizes the general lack of other dating methods that would allow comparison with the tektite age. In the Vietnamese archaeological sites presented here, discrepancies between methods, and the presence of historical artifacts, confirm that the layers do not share similar age with the cosmic impact that created the tektites.
Based on this review and these new results, and following previous propositions , Marwick and colleagues conclude that, if tektites can be used as chronological markers, one has to prove that they are in situ. They propose that geomorphological assessment of the archaeological layer as primary deposit must first be attained, in addition to several parameters of the tektites themselves (shape, size distribution, chemical composition). Large error can be made by using only tektites to date an archaeological layer, and this material should not be used solely due to risks of high overestimation of the age of the archaeological production.
 Rochette, P., Beck, P., Bizzarro, M., Braucher, R., Cornec, J., Debaille, V., Devouard, B., Gattacceca, J., Jourdan, F., Moustard, F., Moynier, F., Nomade, S., Reynard, B. (2021). Impact glasses from Belize represent tektites from the Pleistocene Pantasma impact crater in Nicaragua. Communications Earth & Environment, 2(1), 1–8, https://doi.org/10.1038/s43247-021-00155-1
 Marwick, B., Son, P. T., Brewer, R., Wang, L.-Y. (2022). Tektite geoarchaeology in mainland Southeast Asia. SocArXiv, 93fpa, ver. 6 peer-reviewed and recommended by PCI Archaeology, https://doi.org/10.31235/osf.io/93fpa.
 Tada, T., Tada, R., Chansom, P., Songtham, W., Carling, P. A., Tajika, E. (2020). In Situ Occurrence of Muong Nong-Type Australasian Tektite Fragments from the Quaternary Deposits near Huai Om, Northeastern Thailand. Progress in Earth and Planetary Science 7(1), 1–15, https://doi.org/10.1186/s40645-020-00378-4
A closer look at an eroded dune landscape: first functional insights into the Federmessergruppen site of Lommel-Maatheide
Potential of a large-scale functional analysis to reconstructing past human activities at the Final Palaeolithic site of Lommel-MaatheideRecommended by Marta Arzarello and Alice Leplongeon based on reviews by Ana Abrunhosa and Gabriele Luigi Francesco Berruti
The paper “A closer look at an eroded dune landscape: first functional insights into the Federmessergruppen site of Lommel-Maatheide”  focuses on the final Palaeolithic (Federmesser) site of Lommel-Maatheide. Federmesser sites from northern Belgium such as Lommel-Maatheide, Meer and Rekem, show evidence for dense human occupation of specific areas located on top of Tardiglacial dunes nearby water bodies . Preserved spatial distribution of finds at the sites suggest different activity areas and the presence of habitat structures . However, because of the low organic preservation at the sites, functional analyses of lithic assemblages have the potential to significantly contribute to the spatial organisation of activities at these sites. This study by Tomasso et al. , represents an excellent example of a large-scale integrated approach to the study of lithic industries. The article undoubtedly demonstrates the potential of the proposed methodology and the reliability of the results obtained.
The article explores two different aspects (linked and excellently interconnected here): the possibility to apply use wear, residue and fracture analyses, on lithic assemblages affected by taphonomical alterations and to study lithic assemblages from dune landscapes.
The study allows to answer differentiated questions: what is the influence of taphonomical alterations on use wear analysis? How do excavation methods impact the formation of use wear and the preservation of residues? Can we recognize distinct domestic activities? The article also provides an interesting hypothesis about hunting activities and propulsion methods.
The applied methodology is effectively interdisciplinary and innovative. It demonstrates how a truly integrated and articulated approach can represent the turning point for going beyond a mainly descriptive dimension to move towards a real understanding of the sites.
Studies dedicated to the analysis of the propulsion mode are not very frequent, but they are surely very important to better understand human behaviour . Here, the methodology developed for the evaluation of the propulsion mode represent an important starting point for the definition of a new approach. Morphological and morphometrical analysis are integrated to the evaluation of the mechanical stress, to fracture delineations and to the hafting system (the latter defined on experimental basis).
This article therefore underlines the potential of combining different approaches to functional analysis associated with a ‘tailored’ reference collection and applying them to a high number of artefacts for reconstructing past human activities involving materials that are otherwise not preserved in these contexts.
 Tomasso, S., Cnuts, D., Coppe, J., Geerts, F., Gils, M.V., Bie, M.D., Rots, V. (2021). A closer look at an eroded dune landscape: first functional insights into the Federmessergruppen site of Lommel-Maatheide. https://doi.org/10.31219/osf.io/pf3sm, ver 3 peer-reviewed and recommended by PCI Archaeology.
 De Bie, M., Van Gils, M. (2006). Les habitats des groupes à Federmesser (aziliens) dans le Nord de la Belgique. Bulletin de la Société préhistorique française, 103, 781–790.
 Coppe, J., Lepers, C., Clarenne, V., Delaunois, E., Pirlot, M. and Rots V. (2019). Ballistic Study Tackles Kinetic Energy Values of Palaeolithic Weaponry. Archaeometry, (61)4, 933-956. https://doi.org/10.1111/arcm.12452
Ran-thok and Ling-chhom: indigenous grinding stones of Shertukpen tribes of Arunachal Pradesh, India
An insight into traditional method of food production in IndiaRecommended by Otis Crandell based on reviews by Antony Borel, Birgül Ögüt, Atefe Shekofte, Atefeh Shekofteh, Andrea Squitieri and 1 anonymous reviewer
This paper  covers an interesting topic in that it presents through ethnography an insight into a traditional method of food production which is gradually declining in use. In addition to preserving traditional knowledge, the ethnographic study of grinding stones has the potential for showing how similar tools may have been used by people in the past, particularly from the same geographic region.
 Thongdok Norbu J., Nimasow Gibji, Nimasow Oyi D. (2021) Ran-thok and Ling-chhom: indigenous grinding stones of Shertukpen tribes of Arunachal Pradesh, India. Zenodo, 5118675, ver. 4 peer-reviewed and recommended by PCI Archaeo. doi: https://doi.org/10.5281/zenodo.5118675
The strength of parthood ties. Modelling spatial units and fragmented objects with the TSAR method – Topological Study of Archaeological Refitting
A practical computational approach to stratigraphic analysis using conjoinable material culture.Recommended by Hector A. Orengo based on reviews by Robert Bischoff, Matthew Peeples and 1 anonymous reviewer
The paper by Plutniak  presents a new method that uses refitting to help interpret stratigraphy using the topological distribution of conjoinable material culture. This new method opens up new avenues to the archaeological use of network analysis but also to assess the integrity of interpreted excavation layers. Beyond its evident applicability to standard excavation practice, the paper presents a series of characteristics that exemplify archaeological publication best practices and, as someone more versed in computational than in refitting studies I would like to comment upon.
It was no easy task to find adequate reviewers for this paper as it combines techniques and expertise that are not commonly found together in individual researchers. However, Plutniak, with help from three reviewers, particularly M. Peeples, a leading figure in archaeological applications of network science, makes a considerable effort to be accessible to non-specialist archaeologists. The core Topological Study of Archaeological Refitting (TSAR) method is freely accessible as the R package archeofrag, which is available at the Comprehensive R Archive Network (https://CRAN.R-project.org/package=archeofrag) that can be applied without the need to understand all its mathematical, graph theory and coding aspects. Beside these, an online interface including test data has been provided (https://analytics.huma-num.fr/Sebastien.Plutniak/archeofrag/), which aims to ease access to the method to those archaeologists inexperienced with R. Finally, supplementary material showing how to use the package and evaluating its potential through excellent examples is provided as both pdf and Rmw (Sweave) files. This is an important companion for the paper as it allows a better understanding of the methods presented in the paper and its practical application.
The author shows particular care in testing the potential and capabilities of the method. For example, a function is provided “frag.observer.failure” to test the robustness of the edge count method against the TSAR method, which is able to prove that TSAR can deal well with incomplete information. As a further step in this direction both simulated and real field-acquired data are used to test the method which further proves that archeofrag is not only able to quantitatively assess the mixture of excavated layers but to propose meaningful alternatives, which no doubt will add an increased methodological consistency and thoroughness to previous quantitative approaches to material refitting work, even when dealing with very complex stratigraphies.
All in all, this paper makes an important contribution to core archaeological practice through the use of innovative, reproducible and accessible computational methods. I fully endorse it for the conscious and solid methods it presents but also for its adherence to open publication practices. I hope that it can become of standard use in the reconstruction of excavated stratigraphical layers through conjoinable material culture.
 Plutniak, S. 2021. The Strength of Parthood Ties. Modelling Spatial Units and Fragmented Objects with the TSAR Method – Topological Study of Archaeological Refitting. OSF Preprints, q2e69, ver. 3 Peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.31219/osf.io/q2e69.
A database of lapidary artifacts in the Caribbean for the Ceramic Age
Open data on beads, pendants, blanks from the Ceramic Age CaribbeanRecommended by Ben Marwick based on reviews by Clarissa Belardelli, Robert Bischoff, Stefano Costa and Li-Ying Wang
The paper 'A database of lapidary artifacts in the Caribbean for the Ceramic Age' by Queffelec et al.  presents a description of a dataset of nearly 5000 lapidary artefacts from over 100 sites. The data are dominated by beads and pendants, which are mostly made from Diorite, Turquoise, Carnelian, Amethyst, and Serpentine. The raw material data is especially valuable as many of these are not locally available on the island. This holds great potential for exchange network analysis. The data may be especially useful for investigating one of the fundamental questions of this region: whether the Cedrosan and Huecan are separate, little related developments, with different origins, or variants or a single tradition .
In addition to metric and technological details about the artefacts, the data include a variety of locational details, including coordinates, distance to coast, and altitude. This enables many opportunities for future spatial analysis and geostatistical modelling to understand human behaviours relating to ornament production, use, and discard. I recommend the authors make a minor revision to Table 1 (spatial coverage of the dataset) to make the column with the citations conform to the same citation style used in the rest of the text.
I warmly commend the authors for making transparency and reproducibility a priority when preparing their manuscript. Their use of the R Markdown format for writing reproducible, dynamic documents  is highly impressive. This is an excellent example for others in the international archaeological science community to follow. The paper is especially useful for researchers who are new to R and R Markdown because of the elegant and accessible way the authors document their research here.
 Queffelec, A., Fouéré, P. and Caverne, J.-B. 2021. A database of lapidary artifacts in the Caribbean for the Ceramic Age. SocArXiv, 7dq3b, ver. 4 Peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.31235/osf.io/7dq3b
 Reed, J. A. and Petersen, J. B. 2001. A comparison of Huecan and Cedrosan Saladoid ceramics at the Trants site, Montserrat. In Proceedings of the XVIIIth International Congress for Caribbean Archaeology (pp. 253-267).
 Marwick, B. 2017. Computational Reproducibility in Archaeological Research: Basic Principles and a Case Study of Their Implementation. Journal of Archaeological Method and Theory 24, 424–450. https://doi.org/10.1007/s10816-015-9272-9
A 115,000-year-old expedient bone technology at Lingjing, Henan, China
A step towards the challenging recognition of expedient bone toolsRecommended by Camille Daujeard based on reviews by Jarod Hutson, Delphine Vettese and 1 anonymous reviewer
This article by L. Doyon et al.  represents an important step to the recognition of bone expedient tools within archaeological faunal assemblages, and therefore deserves publication.
In this work, the authors compare bone flakes and splinters experimentally obtained by percussion (hammerstone and anvil technique) with fossil ones coming from the Palaeolithic site of Lingjing in China. Their aim is to find some particularities to help distinguish the fossil bone fragments which were intentionally shaped, from others that result notably from marrow extraction. The presence of numerous (>6) contiguous flake scars and of a continuous size gradient between the lithics and the bone blanks used, appear to be two valuable criteria for identifying 56 bone elements of Lingjing as expedient bone tools. The latter are present alongside other bone tools used as retouchers .
Another important point underlined by this study is the co-occurrence of impact and flake scars among the experimentally broken specimens (~90%), while this association is seldom observed on archaeological ones. Thus, according to the authors, a low percentage of that co-occurrence could be also considered as a good indicator of the presence of intentionally shaped bone blanks.
About the function of these expedient bone tools, the authors hypothesize that they were used for in situ butchering activities. However, future experimental investigations on this question of the function of these tools are expected, including an experimental use wear program.
Finally, highlighting the presence of such a bone industry is of importance for a better understanding of the adaptive capacities and cultural practices of the past hominins. This work therefore invites all taphonomists to pay more attention to flake removal scars on bone elements, keeping in mind the possible existence of that type of bone tools. In fact, being able to distinguish between bone fragments due to marrow recovery and bone tools is still a persistent and important issue for all of us, but one that deserves great caution.
 Doyon, L., Li, Z., Wang, H., Geis, L. and d'Errico, F. 2021. A 115,000-year-old expedient bone technology at Lingjing, Henan, China. Socarxiv, 68xpz, ver. 4 peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.31235/osf.io/68xpz
 Doyon, L., Li, Z., Li, H., and d’Errico, F. 2018. Discovery of circa 115,000-year-old bone retouchers at Lingjing, Henan, China. Plos one, 13(3), https://doi.org/10.1371/journal.pone.0194318.
For our world without sound. The opportunistic debitage in the Italian context: a methodological evaluation of the lithic assemblages of Pirro Nord, Cà Belvedere di Montepoggiolo, Ciota Ciara cave and Riparo Tagliente.
Investigating the opportunistic debitage – an experimental approachRecommended by Alice Leplongeon based on reviews by David Hérisson and 1 anonymous reviewer
The paper “For our world without sound. The opportunistic debitage in the Italian context: a methodological evaluation of the lithic assemblages of Pirro Nord, Cà Belvedere di Montepoggiolo, Ciota Ciara cave and Riparo Tagliente”  submitted by M. Carpentieri and M. Arzarello is a welcome addition to a growing number of studies focusing on flaking methods showing little to no core preparation, e.g., [2–4]. These flaking methods are often overlooked or seen as ‘simple’, which, in a Middle Palaeolithic context, sometimes leads to a dichotomy of Levallois vs. non-Levallois debitage (e.g., see discussion in ).
The authors address this topic by first providing a definition for ‘opportunistic debitage’, derived from the definition of the ‘Alternating Surfaces Debitage System’ (SSDA, ). At the core of the definition is the adaptation to the characteristics (e.g., natural convexities and quality) of the raw material. This is one main challenge in studying this type of debitage in a consistent way, as the opportunistic debitage leads to a wide range of core and flake morphologies, which have sometimes been interpreted as resulting from different technical behaviours, but which the authors argue are part of a same ‘methodological substratum’ .
This article aims to further characterise the ‘opportunistic debitage’. The study relies on four archaeological assemblages from Italy, ranging from the Lower to the Upper Pleistocene, in which the opportunistic debitage has been recognised. Based on the characteristics associated with the occurrence of the opportunistic debitage in these assemblages, an experimental replication of the opportunistic debitage using the same raw materials found at these sites was conducted, with the aim to gain new insights into the method. Results show that experimental flakes and cores are comparable to the ones identified as resulting from the opportunistic debitage in the archaeological assemblage, and further highlight the high versatility of the opportunistic method.
One outcome of the experimental replication is that a higher flake productivity is noted in the opportunistic centripetal debitage, along with the occurrence of 'predetermined-like' products (such as déjeté points). This brings the authors to formulate the hypothesis that the opportunistic debitage may have had a role in the process that will eventually lead to the development of Levallois and Discoid technologies. How this articulates with for example current discussions on the origins of Levallois technologies (e.g., [6–8]) is an interesting research avenue. This study also touches upon the question of how the implementation of one knapping method may be influenced by the broader technological knowledge of the knapper(s) (e.g., in a context where Levallois methods were common vs a context where they were not). It makes the case for a renewed attention in lithic studies for flaking methods usually considered as less behaviourally significant.
 Carpentieri M, Arzarello M. 2020. For our world without sound. The opportunistic debitage in the Italian context: a methodological evaluation of the lithic assemblages of Pirro Nord, Cà Belvedere di Montepoggiolo, Ciota Ciara cave and Riparo Tagliente. OSF Preprints, doi:10.31219/osf.io/2ptjb
 Bourguignon L, Delagnes A, Meignen L. 2005. Systèmes de production lithique, gestion des outillages et territoires au Paléolithique moyen : où se trouve la complexité ? Editions APDCA, Antibes, pp. 75–86. Available: https://halshs.archives-ouvertes.fr/halshs-00447352
 Arzarello M, De Weyer L, Peretto C. 2016. The first European peopling and the Italian case: Peculiarities and “opportunism.” Quaternary International, 393: 41–50. doi:10.1016/j.quaint.2015.11.005
 Vaquero M, Romagnoli F. 2018. Searching for Lazy People: the Significance of Expedient Behavior in the Interpretation of Paleolithic Assemblages. J Archaeol Method Theory, 25: 334–367. doi:10.1007/s10816-017-9339-x
 Forestier H. 1993. Le Clactonien : mise en application d’une nouvelle méthode de débitage s’inscrivant dans la variabilité des systèmes de production lithique du Paléolithique ancien. Paléo, 5: 53–82. doi:10.3406/pal.1993.1104
 Moncel M-H, Ashton N, Arzarello M, Fontana F, Lamotte A, Scott B, et al. 2020. Early Levallois core technology between Marine Isotope Stage 12 and 9 in Western Europe. Journal of Human Evolution, 139: 102735. doi:10.1016/j.jhevol.2019.102735
 White M, Ashton N, Scott B. 2010. The emergence, diversity and significance of the Mode 3 (prepared core) technologies. Elsevier. In: Ashton N, Lewis SG, Stringer CB, editors. The ancient human occupation of Britain. Elsevier. Amsterdam, pp. 53–66.
 White M, Ashton N. 2003. Lower Palaeolithic Core Technology and the Origins of the Levallois Method in North‐Western Europe. Current Anthropology, 44: 598–609. doi:10.1086/377653
Experimentation preceding innovation in a MIS5 Pre-Still Bay layer from Diepkloof Rock Shelter (South Africa): emerging technologies and symbols
Experimentation as a driving force for innovation in the Pre-Still Bay from Southern AfricaRecommended by Anne Delagnes based on reviews by Francesco d'Errico, Kathryn Ranhorn and Enza Elena Spinapolice
The article submitted by Guillaume Porraz et al.  shed light on the evolutionary changes recorded during the Pre-Still Bay Lynn stratigraphic unit (SU) from Diepkloof (Southern Africa). It promotes a multi-proxy and integrative approach based on a set of innovative behaviors, such as the engraving of geometric forms, silcrete heat- treatment, the use of adhesive, bladelet and bifacial tools production. This approach is not so common in Middle Stone Age (MSA) studies and makes a lot of sense for discussing the mechanisms that have fostered later innovations during the Still Bay and Howiesons Poort periods. The various innovations that emerge synchronously in this layer contrast with earlier innovations which appear as isolated phenomena in the MSA archaeological record. The strong inventiveness documented in Lynn SU is reported to a phase of experimentation for testing new ideas, new behaviors that would have played a crucial role for the emergence of the Still Bay in a context of socio-economic transformation.
The data presented in this article broadens the scope of two previous articles [2-3] based on a more representative record, collected on an area of 3,5 m² opposed to 2 m² previously, and on the first presentation and description of an engraved bone with a rhomboid pattern. Macro- and microscopic analyses together with the analysis of the distribution of the engraved lines argue convincingly for an intentional engraving. This article constitutes a key contribution to the question of HOW emerged modern cultures in Southern Africa, while calling for further research related to sites’ function, environment and local resources to address the ever-debated question of WHY the MSA groups from Southern Africa developed such unprecedented inventiveness. It makes no doubt that this article deserves recommendation by PCI Archaeology.
 Porraz, G., Schmidt, P., Bereiziat, G., Brugal, J.Ph., Dayet, L., Igreja, M., Miller, C.E., Viola, C., Tribolo, C., Val, A., Verna, C., Texier, P.J. 2020. Experimentation preceding innovation in a MIS5 Pre-Still Bay layer from Diepkloof Rock Shelter (South Africa): emerging technologies and symbols. 10.32942/osf.io/ch53r
 Porraz, G., Texier, P.J., Archer, W., Piboule, M., Rigaud, J.P, Tribolo, C. 2013. Technological successions in the Middle Stone Age sequence of Diepkloof Rock Shelter, Western Cape, South Africa. Journal of Archaeological Science 40, 3376–3400. 10.1016/j.jas.2013.02.012
 Porraz, G., Texier, J.P. Miller, C.E., 2014. Le complexe bifacial Still Bay et ses modalités d’émergence à l’abri Diepkloof (Middle Stone Age, Afrique du Sud). In: XXVIIème Congrès Préhistorique de France, Transitions, Ruptures et Continuité en Préhistoire. Mémoires de la Société Préhistorique Française, 155–175.
Probabilistic Modelling using Monte Carlo Simulation for Incorporating Uncertainty in Least Cost Path Results: a Roman Road Case Study
A probabilistic method for Least Cost Path calculation.Recommended by Otis Crandell based on reviews by Georges Abou Diwan and 1 anonymous reviewer
The paper entitled “Probabilistic Modelling using Monte Carlo Simulation for Incorporating Uncertainty in Least Cost Path Results: a Roman Road Case Study”  submitted by J. Lewis presents an innovative approach to applying Least Cost Path (LCP) analysis to incorporate uncertainty of the Digital Elevation Model used as the topographic surface on which the path is calculated.
The proposition of using Monte Carlo simulations to produce numerous LCP, each with a slightly different DEM included in the error range of the model, allows one to strengthen the method by proposing a probabilistic LCP rather than a single and arbitrary one which does not take into account the uncertainty of the topographic reconstruction. This new method is integrated in the R package leastcostpath .
The author tests the method using a Roman road built along a ridge in Cumbria, England. The integration of the uncertainty of the DEM, thanks to Monte Carlo simulations, shows that two paths could have the same probability to be the real LCP. One of them is indeed the path that the Roman road took. In particular, it is one of two possibilities of LCP in the south to north direction.
This new probabilistic method therefore strengthens the reconstruction of past pathways, while also allowing new hypotheses to be tested, and, in this case study, to suggest that the northern part of the Roman road’s location was selected to help the northward movements.
 Lewis, J., 2020. Probabilistic Modelling using Monte Carlo Simulation for Incorporating Uncertainty in Least Cost Path Results: a Roman Road Case Study. SocArXiv, mxas2, ver 17 peer-reviewed and recommended by PCI Archaeology, 10.31235/osf.io/mxas2.
 Lewis, J., 2020. leastcostpath: Modelling Pathways and Movement Potential Within a Landscape. R package. Version 1.7.4.
A way to break bones? The weight of intuitiveness
Breaking bones: Nature or Culture?Recommended by Beatrice Demarchi and Reuven Yeshurun based on reviews by Terry O'Connor, Alan Outram and 1 anonymous reviewer
The nature of breaking long bones for obtaining marrow is important in Paleolithic archaeology, due to its widespread, almost universal, character. Provided that hammer-stone percussion marks can be correctly identified using experimental datasets (e.g., ), the anatomical location and count of the marks may be taken to reflect recurrent “cultural” traditions in the Paleolithic . Were MP humans breaking bones intuitively or did they abide by a strict “protocol”, and, if the latter, was this protocol optimized for marrow retrieval or geared towards another, less obvious goal?
The new preprint by Vettese and colleagues  took a novel approach to this question, by conducting an experiment which involved novice butchers, relying on nothing but their intuition, and recording the way in which they broke marrow-rich bones. Some variability was noted in the “intuitive” patterns; indeed, future studies replicating this experiment and adding more variables such as more experienced butchers and non-bovid bones are warranted. Similarities in the means by which novice butchers break bones was also observed, and especially telling is the strong effect of anatomical features in most bones, except for the femur.
This paper provides a baseline for location analyses of percussion marks. Their dataset may therefore be regarded as a null hypothesis according to which the archaeological data could be tested. If Paleolithic patterns of percussion marks differ from Vettese et al.’s  “intuitive” patterns, then the null hypothesis is disproved and one can argue in favor of a learned pattern. The latter can be a result of ”culture”, as Vettese et al.  phrase it, in the sense of nonrandom action that draws on transmitted knowledge. Such comparisons bear a great potential for understanding the degree of technological behavior in the Paleolithic by factoring out the “natural” constraints of bone breakage patterns. Vettese et al. [3: fig. 14] started this discourse by comparing their experimental dataset to some Middle and Upper Paleolithic faunas; we are confident that many other studies will follow.
Pickering, T.R., Egeland, C.P., 2006. Experimental patterns of hammerstone percussion damage on bones: Implications for inferences of carcass processing by humans. J. Archaeol. Sci. 33, 459–469. https://doi.org/10.1016/j.jas.2005.09.001
Blasco, R., Rosell, J., Domínguez-Rodrigo, M., Lozano, S., Pastó, I., Riba, D., Vaquero, M., Peris, J.F., Arsuaga, J.L., de Castro, J.M.B., Carbonell, E., 2013. Learning by Heart: Cultural Patterns in the Faunal Processing Sequence during the Middle Pleistocene. PLoS One 8, e55863. https://doi.org/10.1371/journal.pone.0055863
Vettese, D., Stavrova, T., Borel, A., Marin, J., Moncel, M.-H., Arzarello, M., Daujeard, C. (2020) A way to break bones? The weight of intuitiveness. BioRxiv, 011320, ver. 4 peer-reviewed and recommended by PCI Archaeology. https://doi.org/10.1101/2020.03.31.011320
Investigating relationships between technological variability and ecology in the Middle Gravettian (ca. 32-28 ka cal. BP) in France.
Understanding Palaeolithic adaptations through niche modelling - the case of the French Middle GravettianRecommended by Felix Riede based on reviews by Andreas Maier and João Marreiros
The paper entitled “Investigating relationships between technological variability and ecology in the Middle Gravettian (ca. 32-28 ky cal. BP) in France”  submitted by A. Vignoles and colleagues offers a robust and interesting new analysis of the niche differences between the Rayssian and Noaillian facies of the Middle Gravettian in France.
Understanding technological variability in the Palaeolithic is a long-standing challenge. Previous debates have vacillated between strong, quasi-ethnic culture-historical interpretations rooted in the traditional European school and extreme functional stances that would see artefact forms and their frequencies with assemblages conditioned by site function. While both positions have their merits, many empirical and conceptual caveats haunt them equally [see 2]. In this new study Vignoles and colleagues, so-called eco-cultural niche modelling is applied in an attempt to explore whether, and if so, which environmental background factors may have conditioned the emergence and persistence of two sub-cultural categories (facies) within the Middle Gravettian: the Rayssian and the Noaillian. These are are defined through, respectively, a specific knapping method and the presence of a specific burin type, and the occurrence of these seems divided by the Garonne River. Eco-cultural niche modelling has emerged as an archaeological application of distribution models widely employed in ecology, including palaeoecology, to understand organismal niche envelopes . They constitute powerful tools for using the spatial and chronological information inherent in the archaeological record to up-scale interpretations of human-environment relations beyond individual site stratigraphies or dating series. Another important feature of such models is that their performance can, as Vignoles et al. also show, be formally evaluated and replicated. Following on from earlier applications of such techniques [e.g. 4], the authors here present an interesting study that uses very specific archaeological indicators – namely the Raysse method and the Noaillian burin – as defining features for the units (communities, traditions) whose adaptations they investigate. While broad tool types have previously been used as cultural taxonomic indicators in niche modelling studies , the present study is ambitious in its attempt to understand variability at a relatively small spatial scale. This mirrors equally interesting attempts of doing so in later prehistoric contexts .
Applications of niche modelling that use analytical units defined through archaeological characteristics (technology, typology) are opening up exciting new opportunities for pinning down precisely which environmental or climatic features these cultural components reference, if any. The study by Vignoles et al. makes a good case. At the same time, this approach also acutely raises questions of cultural taxonomy, of how we define our units of analysis and what they might mean . It remains unclear to whether we can define such units on the basis of very different technological traits if the aim is to then use them as taxonomically equivalent in subsequent analyses. There is also a risk that these facies become reified as traditions of sub-cultures – then often further equated with specific people – through an overly normative view of their constituent technological elements. In addition, studies of adaptation in principle need to be conscious of the so-called ‘Galton’s Problem’, where the historical relatedness of the analytical units in question need to be taken into account in seeking salient correlations between cultural and environmental features . In pushing forward eco-cultural niche modelling, the study by Vignoles et al. thus takes us some way forward in understanding the potentially adaptive variability within the Gravettian; future work should consider more strongly the specific historical relatedness amongst the cultural taxa under study and follow more theory-driven definition thereof. Such definition would also allow the post-analysis interpretations of eco-cultural niche modelling to be more explicit. Without doubt, the Gravettian as a whole – including, for instance, phenomena such as the Maisierian  – would benefit from additional and extended applications of this method. Similarly, other periods of the Palaeolithic also characterized by such variability (e.g. the Magdalenian and Final Palaeolithic) offer additional cases moving forward.
 Vignoles, A. et al. (2020). Investigating relationships between technological variability and ecology in 1 the Middle Gravettian (ca. 32-28 ky cal. BP) in France. PCI Archaeology. 10.31219/osf.io/ud3hj
 Dibble, H.L., Holdaway, S.J., Lin, S.C., Braun, D.R., Douglass, M.J., Iovita, R., McPherron, S.P., Olszewski, D.I., Sandgathe, D., 2017. Major Fallacies Surrounding Stone Artifacts and Assemblages. Journal of Archaeological Method and Theory 24, 813–851. 10.1007/s10816-016-9297-8
 Svenning, J.-C., Fløjgaard, C., Marske, K.A., Nógues-Bravo, D., Normand, S., 2011. Applications of species distribution modeling to paleobiology. Quaternary Science Reviews 30, 2930–2947. 10.1016/j.quascirev.2011.06.012
 Banks, W.E., d’Errico, F., Dibble, H.L., Krishtalka, L., West, D., Olszewski, D.I., Townsend Petersen, A., Anderson, D.G., Gillam, J.C., Montet-White, A., Crucifix, M., Marean, C.W., Sánchez-Goñi, M.F., Wolfarth, B., Vanhaeren, M., 2006. Eco-Cultural Niche Modeling: New Tools for Reconstructing the Geography and Ecology of Past Human Populations. PaleoAnthropology 2006, 68–83.
 Banks, W.E., Zilhão, J., d’Errico, F., Kageyama, M., Sima, A., Ronchitelli, A., 2009. Investigating links between ecology and bifacial tool types in Western Europe during the Last Glacial Maximum. Journal of Archaeological Science 36, 2853–2867. 10.1016/j.jas.2009.09.014
 Whitford, B.R., 2019. Characterizing the cultural evolutionary process from eco-cultural niche models: niche construction during the Neolithic of the Struma River Valley (c. 6200–4900 BC). Archaeological and Anthropological Sciences 11, 2181–2200. 10.1007/s12520-018-0667-x
 Reynolds, N., Riede, F., 2019. House of cards: cultural taxonomy and the study of the European Upper Palaeolithic. Antiquity 93, 1350–1358. 10.15184/aqy.2019.49
 Mace, R., Pagel, M.D., 1994. The Comparative Method in Anthropology. Current Anthropology 35, 549–564. 10.1086/204317
 Pesesse, D., 2017. Is it still appropriate to talk about the Gravettian? Data from lithic industries in Western Europe. Quartär 64, 107–128. 10.7485/QU64_5
Platforms of Palaeolithic knappers reveal complex linguistic abilities
The means of complexity in a lithic reduction sequenceRecommended by Marta Arzarello based on reviews by Antony Borel and 1 anonymous reviewer
The paper entitled “Platforms of Palaeolithic knappers reveal complex linguistic abilities”  submitted by C. Gaucherel and C. Noûs represents an interesting reflection about the possibilities to detect the human cognitive abilities in relation to the lithic production.
The definition and the study of human cognitive abilities during the Lower Palaeolithic it has always been a complex field of investigation. The relation between the technical skills (lithic production) and the emergence of the linguistic abilities is not easy to investigate due to the difficulty of finding objective data to refer to. The proposition, made by C. Gaucherel and C. Noûs, of a formal grammar of knapping as a method to study the syntactical organisation of the reduction sequences, constitute a new and theoretical useful approach.
In order to effectively and precisely define the gestures linked to a specific reduction sequence, for example that of the handaxes shaping, a very large number of variables should be taken into consideration (morphology and quality of the raw material, experience of the knapper, context, percussion technique, forecast of use of the handaxe, etc.). But since a simplification, that brings more elements than the classic one [2,3] is needed, the “action grammar approach” can be a good instrument to detect the common element in a shaping reduction sequence. Furthermore, one of the advantages of the proposed methodology lies in the fact that the definition of the different STs (Stone Technology) can be done according to the technological specific characteristics to be studied and to the type of instrument produced.
The deconstruction of knapping sequences could help to detect the degree of complexity of the different steps of the reduction sequences also thanks to the identification of the sub-actions types. The increasing/decreasing of complexity is a very complicate concept in lithic technology. Since at the base of the lithic production there are two basic concepts (angle between the striking platform and the debitage surface - convexity of the debitage/façonnage surface) which are simply declined in an increasingly complex way, it is not easy to define uniquely in what exactly consists the increase in complexity. The approach proposed in the paper “Platforms of Palaeolithic knappers reveal complex linguistic abilities” can help to have new evidences, according to the identification of the required cognitive abilities.
The proposed example of formal grammar still needs to be confirmed on archaeological collections, but it is probable that a practical application will allow to further develop the methodology and possibly to highlight additional possibilities of the approach.
 Gaucherel, C. and Noûs C. (2020). Platforms of Palaeolithic knappers reveal complex linguistic abilities. Paleorxiv, wn5za, ver. 6 peer-reviewed and recommended by PCI Archaeology. doi: 10.31233/osf.io/wn5za
 Inizian, M. L., Reduron, M., Roche, H. and Tixier, J. (1995). Technologie de la pierre taillée. Préhistoire de la Pierre Taillée 4, Cercle de Recherches et d'Etudes Préhistoriques d'Antibes, Meudon.
 Tixier, J., Inizian, M. L. and Roche, H. (1980). Terminologie et technologie. Préhistoire de la pierre taillée 1, Cercle de Recherches et d'Etudes Préhistoriques d'Antibes, Meudon.
TIPZOO: a Touchscreen Interface for Palaeolithic Zooarchaeology. Towards making data entry and analysis easier, faster, and more reliable
A new software to improve standardization and quality of data in zooarchaeologyRecommended by Florent Rivals based on reviews by Argant Thierry and Delphine Vettese
Standardization and quality of data collection are identified as challenges for the future in zooarchaeology . These issues were already identified in the early 1970s when the International Council for Archaeozoology (ICAZ) recommended to “standardize measurements and data in publications”. In the recent years, there is strong recommendations by publishers and grant to follow the FAIR Principle i.e. to “improve the findability, accessibility, interoperability, and reuse of digital assets” . As zooarchaeologists, we should make our methods more clear and replicable by other researchers to produce comparable datasets. In this paper the authors make a significant step in proposing a tool to replace traditional data recording softwares. The problems related to data recording are clearly identified and discussed. All the features offered by TIPZOO allow to standardize the data, to reduce the errors when entering the data, to save time with auto-filling entries. The coding system used in TIPZOO is based on variables taken from the most used and updated literature in zooarchaeology. Its connections with various R packages allow to directly export the data and to transform the raw data to produce summary tables, graphs and basic statistics. Finally, the advantage of this tool is that it can be improved, debugged, or implemented at any time. TIPZOO provides a standardized system to compile and share large and consistent datasets that will allow comparison among assemblages at a large scale, and for this reason, I have recommended the work for PCI Archaeology.
 Steele, T.E. (2015). The contributions of animal bones from archaeological sites: the past and future of zooarchaeology. J. Archaeol. Sci. 56, 168–176. doi: 10.1016/j.jas.2015.02.036