RSS 1.0Earth sciences
The Museum's vast collections of meteorites, rocks, minerals and fossils support our staff's unique expertise in natural resources, planetary geology and the evolution of life on Earth.
Recent Submissions
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Coastal seawater turbidity and thermal stress control growth of reef-building Porites spp. corals in FijiNearshore reefs, at the interface of land-sea interactions, provide essential ecosystem services, but are susceptible to multiple global and local stressors. These stressors can detrimentally impact coral growth and the continuity of the reef framework. Here, we analyse coral growth records (1998 – 2016) of massive <jats:italic>Porites</jats:italic> spp. colonies from nearshore reefs in Fiji. Our aim is to assess the role of thermal stress and turbidity on coral growth across a range of environments. Our findings reveal a negative linear relationship between linear extension and seawater turbidity across locations (GLM, R<jats:sup>2</jats:sup> = 0.42, <jats:italic>p</jats:italic> < 0.001), indicating that average coral growth is significantly influenced by local environmental conditions. On interannual timescales, all locations experienced a 14% to 30% decrease in linear extension in response to acute thermal stress during the 2013 – 2016 period. This finding highlights the existence of compounding effects between water quality and thermal stress. We suggest that inshore, long-lived massive hard corals in areas of high turbidity are more vulnerable to increasing SSTs due to an already reduced mean growth. Integrated management strategies in these regions that considers managing for multiple, interacting local stressors are warranted to enhance resilience.
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The evolutionary history and timeline of mites in ancient soilsAcariform mites play a crucial role as primary soil decomposers, impacting the carbon cycle. However, the timing of their diversification is uncertain, with estimated dates ranging from the Precambrian (no land plants) to the Carboniferous (diverse terrestrial ecosystems). One factor affecting these time estimates is an uncertain phylogenetic position of the earliest unequivocal fossil mites from the Devonian Rhynie Chert, which have been classified in five modern families and three suborders. Here, we thoroughly examine these specimens, assign them to a single species Protacarus crani (family Protoacaridae, fam. nov., suborder Endeostigmata) and integrate this information into a time-calibrated phylogenetic analysis. Our phylogeny suggests a Cambrian basal divergence of Acariformes (508-486 Ma), coinciding with the land colonization by bryophytes. At this time, the mites' ecological niches were probably diversified beyond the upper soil. Our study provides temporal context, improves the accuracy of fossil dating, and underscores the importance of mites' diverse habitats and their potential roles in soil food webs.
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Gregarious behaviour in Carboniferous cyclidan crustaceansGregarious behaviours in modern and fossil arthropods are commonly associated with defensive strategies, mass moulting and synchronous reproduction. Such behaviour is scarcely documented in the crustacean fossil record. Identifying clusters in extinct Pancrustacea is, therefore, important for understanding the evolutionary history and origin of crustacean gregariousness. Cyclida, an order of extinct, enigmatic pancrustaceans that have been subject to limited palaeoecological examination, represents an ideal group for testing the presence of gregarious behaviour. Here, we report a cluster of 50 <jats:italic>Schramine montanaensis</jats:italic> individuals from the Serpukhovian-aged Bear Gulch Limestone of Montana, USA, expanding the exceptionally rare record of cyclidan aggregations. The presence of articulated specimens with appendages and possible gill preservation supports the interpretation of carcasses that were preserved during a rapid burial event. We propose that this cluster records either a mass moulting event or clustering for shelter, representing one of the oldest records of crustacean gregariousness. These findings provide important insights into cyclidan life modes and ecological interactions in Carboniferous marine environments.
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A new euarthropod from the Soom Shale (Ordovician) Konservat‐Lagerstätte, South Africa, with exceptional preservation of the connective endoskeleton and myoanatomyA new exceptionally preserved euarthropod, Keurbos susanae gen. et sp. nov. from the Upper Ordovician Soom Shale Konservat‐Lagerstätte of South Africa, is described herein. Two specimens exhibit an unusual preservation style such that the cuticular exoskeleton is preserved in low relief but retains high‐fidelity details, whereas the internal anatomy is preserved in three dimensions and includes myoanatomy and aspects of the connective inter‐ and intrasegmental endoskeleton. The trunk has 46 homonomous segments and tapers towards the posterior. The dorsal surface comprises the posterior margins of tergites that form rounded paratergal folds at their lateral margins. Sternal morphology is seen from an internal view of the fossils and includes axial sternites and associated ovoid plates, both with fringing setae along their posterior margins. Patchy, incomplete preservation of the appendages is consistent with the ‘reversed’ taphonomy of these fossils in which sclerotized elements that project beyond the body margin, such as lamellae with vascular channels and pits, are preserved, whereas those inside the body margins are absent or poorly expressed. Euarthropod characters include an arthrodized tergal and sternal exoskeleton, and a segmental connective endoskeleton. Recent depopulation of the euarthropod stem group has witnessed conspicuously arthrodized fossils formerly placed in the stem group being shifted into the crown, increasing the likelihood that <jats:italic>Keurbos</jats:italic> is likewise a crown‐group euarthropod. Comparison with a phylogenetically disparate suite of similarly homonomous, multisegmented taxa indicates no convincing synapomorphies. The grouping of relevant middle Palaeozoic exemplars as ‘enantiopod’ pancrustaceans could suggest that Keurbos might be allied.
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Centipedes (Myriapoda, Chilopoda) of Aldabra Atoll (Seychelles)Centipedes collected during Royal Society surveys of the arthropod fauna of the Aldabra Atoll in 1968–1975 are identified, described, and illustrated to provide the first checklist to the Aldabran centipede fauna, comprising 12 species. These newly include the lithobiomorph <jats:italic>Lamyctes tristani</jats:italic> (Pocock, 1893), the scolopendromorphs <jats:italic>Scolopendra morsitans</jats:italic>Linnaeus 1758, Cryptops cf. japonicus Takakuwa, 1934, <jats:italic>Cryptops mauritianus</jats:italic> Verhoeff, 1939, and <jats:italic>Cryptops nigropictus</jats:italic> Takakuwa, 1936, and the geophilomorphs Ityphilus cf. taeniaformis (Lawrence, 1960), <jats:italic>Mecistocephalus angusticeps</jats:italic> (Ribaut, 1914), <jats:italic>Mecistocephalus lohmanderi</jats:italic> Verhoeff, 1939, <jats:italic>Orphnaeus dekanius</jats:italic> Verhoeff, 1938, Ribautia cf. paucipes Attems, 1952, and <jats:italic>Tuoba sydneyensis</jats:italic> (Pocock, 1891). The geophilomorph genera <jats:italic>Hovanyx</jats:italic> Lawrence, 1960, <jats:bold>syn. nov.</jats:bold>, and <jats:italic>Mixophilus</jats:italic> Silvestri, 1929, <jats:bold>syn. nov.</jats:bold>, are revised in light of the examined material and hereby designated junior subjective synonyms of <jats:italic>Tuoba</jats:italic> Chamberlin, 1920 with the species <jats:italic>Geophilus lemuricus</jats:italic> Verhoeff, 1939, <jats:bold>syn. nov.</jats:bold>, and <jats:italic>Hovanyx waterloti</jats:italic> Lawrence, 1960, <jats:bold>syn. nov.</jats:bold>, designated as junior subjective synonyms of <jats:italic>T. sydneyensis</jats:italic>. The oryid genus <jats:italic>Nycternyssa</jats:italic> Crabill, 1959, <jats:bold>syn. nov.</jats:bold>, is revised and designated a junior subjective synonym of <jats:italic>Orphnaeus</jats:italic> Meinert, 1870. New data on intraspecific morphological variation are presented for <jats:italic>C. nigropictus</jats:italic>, with the validity of <jats:italic>Cryptops daszaki</jats:italic> Lewis, 2002 being questioned following examination of its type material. The affinities and possible origins of the Aldabran centipede fauna are found to be mainly East African, with several species occurring across other islands in the Western Indian Ocean.
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Crystallographic and geochemical responses of giant clams on turbid reefsMarine calcifying organisms on coral reefs face significant threats from various anthropogenic stressors. To better understand how these organisms will respond to a rapidly changing ocean, it is crucial to investigate their biomineralization across different reef environments. Despite their resilience and potential as conservation hotspots, turbid reefs—projected to expand throughout the 21st century—remain understudied, including a limited knowledge of biomineralization processes within these environments. Herein, for the first time, we assess the crystallographic and geochemical signatures of aragonite giant clam shells <jats:italic>Tridacna squamosa</jats:italic> from high and low turbid reefs in the Coral Triangle. Shell composition is strongly influenced by turbidity and biominerals formed in a high turbid reef show a more organized crystal orientation and significantly lower element-to-calcium ratios (magnesium/calcium, strontium/calcium). We hypothesize that these variations are driven by physiological changes related to the trophic flexibility of <jats:italic>T. squamosa</jats:italic>, utilizing both autotrophic and heterotrophic mechanisms. Observed differences may have implications for biomechanical and defense responses of shells, important in their ability to survive future change.
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A biological nanofoam: The wall of coniferous bisaccate pollenThe outer layer of the pollen grain, the exine, plays a key role in the survival of terrestrial plant life. However, the exine structure in different groups of plants remains enigmatic. Here, modern and fossil coniferous bisaccate pollen were examined to investigate the detailed three-dimensional structure and properties of the pollen wall. X-ray nanotomography and volume electron microscopy are used to provide high-resolution imagery, revealing a solid nanofoam structure. Atomic force microscopy measurements were used to compare the pollen wall with other natural and synthetic foams and to demonstrate that the mechanical properties of the wall in this type of pollen are retained for millions of years in fossil specimens. The microscopic structure of this robust biological material has potential applications in materials sciences and also contributes to our understanding of the evolutionary success of conifers and other plants over geological time.
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Human remains from the River Thames: new dating evidenceThe River Thames, winding through the English capital of London, is the source of a substantial archaeological assemblage that includes hundreds of human bones, but the lack of a robust chronology for these finds limits interpretation. Here, 30 new radiocarbon dates are reported for the human remains. In combination with other available dates (some of which are also published here for the first time), this improved chronological framework demonstrates a predominance of Bronze and Iron Age dates and emphasises the need to explore the Thames assemblage in the broader context of watery deposition practices of later prehistoric north-west Europe.
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Magma recharge and mush rejuvenation drive paroxysmal activity at Stromboli volcanoAbstract - Open-conduit basaltic volcanoes can be characterised by sudden large explosive events (paroxysms) that interrupt normal effusive and mild explosive activity. In June-August 2019, one major explosion and two paroxysms occurred at Stromboli volcano (Italy) within only 64 days. Here, via a multifaceted approach using clinopyroxene, we show arrival of mafic recharges up to a few days before the onset of these events and their effects on the eruption pattern at Stromboli, as a prime example of a persistently active, open-conduit basaltic volcano. Our data indicate a rejuvenated Stromboli plumbing system where the extant crystal mush is efficiently permeated by recharge magmas with minimum remobilisation promoting a direct linkage between the deeper and the shallow reservoirs that sustains the currently observed larger variability of eruptive behaviour. Our approach provides vital insights into magma dynamics and their effects on monitoring signals demonstrating the power of petrological studies in interpreting patterns of surficial activity.
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Modelling ancient magma plumbing systems through clinopyroxene populations: a case study from Middle Triassic volcanics (Dolomites, Italy)Abstract - Modelling plumbing systems dynamics of active volcanoes through textural and chemical studies of mineral phases is crucial to unravel their eruptive behaviour, but it is rarely applied in ancient volcanic and volcano-plutonic systems. Here, we present an investigation of the architecture, magma dynamics and pre-eruptive timing of Middle Triassic plumbing systems in the Dolomites area (Southern Alps) through a detailed investigation of textures and compositional zoning of clinopyroxenes in lavas and dykes from Predazzo, Mt. Monzoni, Cima Pape and Sciliar volcano-plutonic complexes. The clinopyroxene composition varies between low-Mg# (67–78), low-Cr augite and high-Mg# (77–91), Cr-rich diopside. Diopside is less frequent and appears as variably thick single or multiple bands between augitic cores and rims or as resorbed homogeneous, or patchy-zoned and mottled cores. Rims are homogeneous or oscillatory zoned, with augitic composition. The mid- to low-crustal plumbing systems of all volcanic centres were characterised by the presence of a mildly evolved trachyandesitic magma (Mg# 45; T = 1044–1118 °C), where augitic clinopyroxene formed. Periodic mafic injections of more primitive and hotter trachybasaltic magma (Mg# 56; T = 1056–1170 °C) caused frequent crystallisation of diopsidic bands around augitic cores. The presence of resorbed or patchy-zoned mottled diopsidic cores in clinopyroxene phenocrysts, as well as of rare clinopyroxenitic xenoliths with analogous diopsidic composition, indicates the recycling and remobilisation of antecrysts from the deeper part of the plumbing system, which was probably located at a depth of 10–17 km. Diffusion chronometry models based on Fe–Mg interdiffusion in clinopyroxene revealed that the time elapsed from the mafic injection into the shallow portion of the plumbing systems to the eruption ranges from decades to < 1 year. Our findings enabled us to resolve the different plumbing system dynamics acting at the local scale beneath each volcanic centre. Our data indicate a striking similarity with magma dynamics and timing of pre-eruptive processes at active volcanoes: therefore, we posit that this work sets a starting point to deepen our knowledge of the volcano-plutonic links and, in turn improves our ability to interpret the main processes acting in active plumbing systems.
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Magma recharge patterns control eruption styles and magnitudes at Popocatépetl volcano (Mexico)Abstract - Diffusion chronometry has produced petrological evidence that magma recharge in mafic to intermediate systems can trigger volcanic eruptions within weeks to months. However, less is known about longer-term recharge frequencies and durations priming magma reservoirs for eruptions. We use Fe-Mg diffusion modeling in orthopyroxene to show that the duration, frequency, and timing of pre-eruptive recharge at Popocatépetl volcano (Mexico) vary systematically with eruption style and magnitude. Effusive eruptions are preceded by 9–13 yr of increased recharge activity, compared to 15–100 yr for explosive eruptions. Explosive eruptions also record a higher number of individual recharge episodes priming the plumbing system. The largest explosive eruptions are further distinguished by an ~1 yr recharge hiatus directly prior to eruption. Our results offer valuable context for the interpretation of ongoing activity at Popocatépetl, and seeking similar correlations at other arc volcanoes may advance eruption forecasting by including constraints on potential eruption size and style.
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A new Late Triassic sauropodomorph dinosaur from the Mid-Zambezi Basin, ZimbabweAn articulated partial hind limb collected from the Pebbly Arkose Formation (Norian, Upper Triassic) of the Upper Karoo Group of Zimbabwe is described as a new taxon of sauropodomorph dinosaur. Musankwa sanyatiensis gen. et sp. nov. was discovered on the shoreline of Lake Kariba, on Spurwing Island in the Mid-Zambezi Basin. The holotype consists of a right femur, tibia, and astragalus, and can be distinguished from all other Late Triassic massopodan sauropodomorphs on the basis of numerous features, which form a unique character combination. Phylogenetic analysis recovers the new taxon as the earliest-branching lineage within Massopoda. Musankwa is only the fourth dinosaur to be named from the Karoo-aged basins of Zimbabwe and further demonstrates the high potential of this region for discoveries of new early dinosaur material.
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Palaeoenvironment and taphonomy of the Hypsilophodon Bed, Lower Cretaceous Wessex Formation, Isle of WightThe Hypsilophodon Bed occurs at the top of the Wessex Formation (Early Cretaceous, Barremian) on the Isle of Wight, southern England. Numerous remains of the small ornithopod dinosaur Hypsilophodon foxii have been recovered from the bed since the mid-nineteenth century. Previous theories for these fossil occurrences have focused on catastrophic mass death events, including miring and flood-related mortality. However, only limited sedimentological and taphonomic analyses of the horizon and its fossil assemblage have been undertaken, hindering efforts to evaluate different theories about how the assemblage formed. Here, we report a sedimentological study of the bed to constrain its depositional environment, an examination of the matrix from Hypsilophodon fossils to identify where they were collected from within the bed, and a taphonomic investigation of Hypsilophodon specimens. Our results indicate a floodplain environment, which later became a marsh and then mudflats at the edge of a lagoon. Hypsilophodon fossils are spatially and stratigraphically distributed throughout the bed. The specimens are largely incomplete and unabraded, suggesting that most perished on, or near to, the floodplain and may have lain exposed for some time prior to burial. Overall, the evidence suggests that the fossil assemblage of the Hypsilophodon Bed formed as an accumulation of remains over time.
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Restructuring of Femoral Cortical Bone During Growth and Locomotor Development of Wild Chimpanzees (Pan troglodytes verus)ABSTRACT Objective - Chimpanzees are altricial in terms of their locomotor development and transition from being carried to engaging in suspensory and arboreal locomotor behaviors to eventually relying on terrestrial quadrupedalism as their main form of locomotion. Here, we consider the mechanical implications of femoral cortical bone restructuring during growth and locomotor development in wild chimpanzees. Materials and Methods - Cortical bone structure was examined in an ontogenetic sample of wild chimpanzees from a single subspecies (P. t. verus) spanning in age from 2 weeks to 12.6 years. Diaphyseal cross‐sections were extracted from micro‐CT scans of the femur at 35%, 50%, and 65% of total intermetaphyseal length and variation in cortical bone structure was assessed based on bending rigidity (Imax/Imin, Ix/Iy), relative medullary area, and cortical bone porosity. Results - Diaphyseal shape is relatively circular with a high amount of cortical bone porosity and a large relative medullary area during early infancy. Distinct shifts in cortical bone structure occurred for each studied parameter with the biggest changes occurring within the first 5 years. Values appear to stabilize as quadrupedal walking increases in frequency and is established as the main form of locomotion. Discussion - Collectively, the results suggest a degree of integration in which cortical bone restructures in response to rapid changes in locomotion in addition to nonmechanical influences such as hormonal, and growth factors, without compromising function and structural integrity. The extent of influence of each factor varies throughout growth and highlights the need for caution in functional interpretations of cortical bone geometry.
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Late pleistocene exploitation of Ephedra in a funerary context in MoroccoThe active compounds found in many plants have been widely used in traditional medicine and ritual activities. However, archaeological evidence for the use of such plants, especially in the Palaeolithic period, is limited due to the poor preservation and fragility of seed, fruit, and other botanical macro-remains. In this study, we investigate the presence and possible uses of Ephedra during the Late Pleistocene based on the analysis of exceptionally preserved plant macrofossils recovered from c. 15 ka year-old archaeological deposits at Grotte des Pigeons in northeastern Morocco. This cave has yielded the earliest carbonized plant macrofossils of Ephedra, which were found concentrated in a human burial deposit along with other special finds. Ephedra is a plant known to produce high amounts of alkaloids, primarily ephedrine and pseudoephedrine, which have been utilized in traditional medicine. Direct radiocarbon dates on both Ephedra and the human remains indicate that they were contemporaneous. To understand the uses of Ephedra by people at the site, we discuss the different pathways through which plant remains could have arrived. We suggest that the charred cone bracts of Ephedra likely represent residues of the processing and consumption of the plant's fleshy cones, which may have been valued for both their nutritional and therapeutic properties. Furthermore, we interpret the presence of Ephedra and its deposition in the burial area as evidence that this plant played a significant role during the funerary activities.
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The evolution and changing ecology of the African hominid oral microbiomeSignificance The microbiome plays key roles in human health, but little is known about its evolution. We investigate the evolutionary history of the African hominid oral microbiome by analyzing dental biofilms of humans and Neanderthals spanning the past 100,000 years and comparing them with those of chimpanzees, gorillas, and howler monkeys. We identify 10 core bacterial genera that have been maintained within the human lineage and play key biofilm structural roles. However, many remain understudied and unnamed. We find major taxonomic and functional differences between the oral microbiomes of Homo and chimpanzees but a high degree of similarity between Neanderthals and modern humans, including an apparent Homo-specific acquisition of starch digestion capability in oral streptococci, suggesting microbial coadaptation with host diet.
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New Chilopoda from the Chagos ArchipelagoThe single published record of centipedes from the Chagos Archipelago, British Indian Ocean Territory, is for the scolopendrid Rhysida longipes Newport, 1845, from Eagle Island. Recent collections from Diego Garcia atoll include new records of R. longipes as well as four other centipede species, including the first records of the orders Lithobiomorpha and Geophilomorpha. A new species of the lithobiid Australobius Chamberlin, 1920, A. chagosensis sp. n., is closely allied to species described from southern India, Sri Lanka and the Maldives. The henicopid Lamyctes is represented by two geographically widespread species, L. mauriesi Demange, 1981 and L. tristani (Pocock, 1893), from which sequence data for the COI barcode marker are presented and analysed phylogenetically. The types of Lamyctes albipes (Pocock, 1894), and L. tristani, from Java and Tristan da Cunha, respectively, are illustrated for the first time to facilitate taxonomic comparisons with Chagos material. Specimens of Mecistocephalus are identified as Mecistocephalus lohmanderi Verhoeff, 1939, closely resembling specimens from the Seychelles. Collections from the archipelago in 1971–1972 also included Mecistocephalus angusticeps (Ribaut, 1914), and Nycternyssa dekania dekania (Verhoeff, 1938). The Chagos centipede fauna reveals affinities to those of the southern Indian Subcontinent, East Africa, Madagascar, the Maldives, the Seychelles, and Java. http://www.zoobank.org/urn:lsid:zoobank.org:pub:52337A1E-95DF-46C5-9D9A-8F294968A89D
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Palaeoscolecids from the Ludlow Series of Leintwardine, Herefordshire (<scp>UK</scp>): the latest occurrence of palaeoscolecids in the fossil recordAbstract - The documentation of cuticular micro‐ornament is vital for the taxonomic assignment of palaeoscolecids: vermiform lower Palaeozoic ecdysozoans interpreted as stem‐group priapulans or early diverging panarthropods. This is due to the absence of the character‐rich proboscis and tail hooks in palaeoscolecid material not from Burgess Shale‐type Konservat‐Lagerstätten. Here, the cuticular micro‐ornamentation of palaeoscolecids from the upper Silurian (Ludlow) fauna of Leintwardine (Herefordshire, England), is described using scanning electron microscopy and reflectance transformation imaging. This material is taxonomically unstable because it was included in an effective wastebasket genus (Protoscolex) long before these imaging techniques were developed. The Leintwardine material is shown to be most closely comparable to a palaeoscolecid from the Darriwilian (Middle Ordovician) of the Builth–Llandrindod inlier, Powys, Wales, and is transferred accordingly to Radnorscolex Botting et al. as Radnorscolex latus (Bather). The Leintwardine fauna represents the uppermost stratigraphic occurrence of palaeoscolecids, constrained to the Saetograptus leintwardinensis Zone (lower Ludfordian), and the comparatively sparse Silurian palaeoscolecid record is subsequently discussed. It is hypothesized that palaeoscolecids may have become extinct during the mid‐Ludfordian Lau Event, the onset of which is recorded in the biozone immediately above the Leintwardine fauna (Bohemograptus Zone). Finally, the British palaeoscolecid fauna is summarized, including a new record from the Dapingian (Middle Ordovician) of Carmarthenshire, South Wales.
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A new sauropod dinosaur hindlimb from the Lower Cretaceous Wessex Formation, Isle of Wight, UKThe Barremian-aged Wessex Formation of the Isle of Wight, UK, offers a globally significant glimpse into the sauropod dinosaur faunas of the early Cretaceous. These deposits have yielded specimens of several neosauropod lineages, such as rebbachisaurids, titanosauriforms (including some of the earliest titanosaur remains), and possible flagellicaudatans. Here, we report an undescribed sauropod partial hindlimb from the Wessex Formation (NHMUK PV R16500) and analyse its phylogenetic affinities. This hindlimb preserves the left tibia, astragalus and pes, lacking only a few phalanges. NHMUK PV R16500 can be diagnosed based on two autapomorphies: an unusually high distal end to midshaft transverse width ratio in metatarsals III and IV, and the presence of small bump-like projections located in the centre of the proximal articular surfaces of the unguals of pedal digits I and II. The phylogenetic affinities of NHMUK PV R16500 are uncertain: although our analyses recover it as an early-branching somphospondylan, a single character change moves it to close to Flagellicaudata when extended implied weighting is applied. The possibility of flagellicaudatan affinities for NHMUK PV R16500 implies a potential ghost lineage that survived the Jurassic/Cretaceous boundary; however, we present evidence that the somphospondylan position is more probable and should be preferred.
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Bone retouchers and technological continuity in the Middle Stone Age of North AfricaEvidence for specialised bone tools has recently been reported for the Middle Stone Age of North Africa [one], which complements similar finds of slightly younger age in South Africa [two, three]. However, until now scant reference has been made to lesser known tools also made of bone ('bone retouchers') that were employed specifically as intermediaries for working or refining stone artefacts, that are sometimes present in these assemblages. In this paper we describe 20 bone retouchers from the cave of Grotte des Pigeons at Taforalt in north-east Morocco. This is the largest stratified assemblage of bone retouchers from a North African MSA site, and the biggest single collection so far from the African Continent. A total of 18 bone retouchers was recovered in securely dated archaeological levels spanning a period from ~ 84.5 ka to 24 ka cal BP. A further two bone retouchers were found in a layer at the base of the deposits in association with Aterian artefacts dating to around 85,000 BP and so far represent the earliest evidence of this type of tool at Taforalt. In this paper we present a first, detailed description of the finds and trace the stages of their production, use and discard (chaîne opératoire). At the same time, we assess if there were diachronic changes in their form and function and, finally, explore their presence in relation to stone tools from the same occupation layers of the cave.
