Muséum National d'Histoire Naturelle

The gray mouse lemur ( Microcebus murinus ), one of the smallest living primates, emerges as a promising model organism for neuroscience research. This is due to its genetic similarity to humans, its evolutionary position between rodents and humans, and its primate-like features encapsulated within a rodent-sized brain. Despite its potential, the absence of a comprehensive reference brain atlas impedes the progress of research endeavors in this species, particularly at the microscopic level. Existing references have largely been confined to the macroscopic scale, lacking detailed anatomical information. Here, we present eLemur, a unique resource, comprising a repository of high-resolution brain-wide images immunostained with multiple cell type and structural markers, elucidating the cyto- and chemoarchitecture of the mouse lemur brain. Additionally, it encompasses a segmented two-dimensional reference and 3D anatomical brain atlas delineated into cortical, subcortical, and other vital regions. Furthermore, eLemur includes a comprehensive 3D cell atlas, providing densities and spatial distributions of non-neuronal and neuronal cells across the mouse lemur brain. Accessible via a web-based viewer ( https://eeum-brain.com/#/lemurdatasets ), the eLemur resource streamlines data sharing and integration, fostering the exploration of different hypotheses and experimental designs using the mouse lemur as a model organism. Moreover, in conjunction with the growing 3D datasets for rodents, nonhuman primates, and humans, our eLemur 3D digital framework enhances the potential for comparative analysis and translation research, facilitating the integration of extensive rodent study data into human studies.

This paper presents the results of the research conducted at the site of Fardowsa, a medieval town located in a strategic trade route in Central Somaliland. The excavations and surveys conducted at the site have confirmed the role of Fardowsa as a trading center between the 14th and 16th centuries, and have revealed the existence of privileged households within the site, with differential access to imports and livestock. The combination of data collected in Fardowsa makes this site the best-studied town in Somaliland for this period, and provides key information to help understand the process of emergence, development and abandonment of permanent settlements in this region of the Horn of Africa.

Since 2013, we have undertaken a detailed study of terrestrial flatworms (Geoplanidae) introduced into mainland France (including Corsica). Around ten species have been listed, mapped, and often characterized molecularly. These species include, in alphabetical order, Bipalium kewense, Caenoplana coerulea, Caenoplana decolorata, Caenoplana variegata, Diversibipalium multilineatum, Marionfyfea adventor, Obama nungara, Parakontikia ventrolineata, Platydemus manokwari, and Vermiviatum covidum. Outside of mainland France, we also studied species from the French islands of the Caribbean (Guadeloupe, Martinique), Réunion and Mayotte in the Indian Ocean, as well as New Caledonia, French Polynesia, and Wallis and Futuna in the Pacific. Two new species have been described. The major invasive species in mainland France are Obama nungara, present in two thirds of the country, Caenoplana variegata, and Parakontikia ventrolineata (especially in Brittany). Bipalium kewense and Diversibipalium multilineatum are mainly present in the southwest region of the French Atlantic coast. The origins of invasive species in France are varied and include Argentina (Obama nungara), Australia (Caenoplana variegata and Parakontikia ventrolineata), and Southeast Asia (Bipaliinae). We have characterized and published the complete mitogenomes of 12 species, with unexpected results, such as the very long cox2 gene in Rhynchodeminae. The phylogenies built on the genes of the mitogenomes generally confirm the previous classifications of the subfamilies of Geoplanidae, and individualize the three subfamilies Rhynchodeminae, Geoplaninae, and Bipaliinae. We emphasize the importance of citizen science for obtaining data, and the importance of good communication with the public to obtain significant engagement towards citizen science. KEYWORDS: Citizen science; invasive alien species; mitogenome

†Cryptovaranoides microlanius from the latest Triassic of England was described in 2022 as a crown-clade squamate, of importance as the oldest such modern-type lizard, extending their temporal range downward by 35 Myr. This view was challenged in 2023, and †Cryptovaranoides was reinterpreted as an archosauromorph. These decisions matter because the original view has an impact on our understanding of the early stages of squamate evolution; the revised view removes the species from such a role. The revisers emphasized the need to make careful observations of the fossils and to interpret the morphological data appropriately in terms of relationships; here, we find many errors of observation and interpretation in the work of the revisers, and we correct these with reference to the fossils, both in the rock and in the computed tomography scans we had made for the original description. We show that when the observational errors are corrected and the taxa recoded, every phylogenetic analysis confirms our original conclusion that †Cryptovaranoides is not an archosauromorph, but a lepidosauromorph, a lepidosaur, a pan-squamate and a crown squamate.

Nucleosynthetic isotope variations are powerful tracers to determine genetic relationships between meteorites and planetary bodies. They can help to link material collected by space missions to known meteorite groups. The Hayabusa 2 mission returned samples from the Cb‐type asteroid (162173) Ryugu. The mineralogical, chemical, and isotopic characteristics of these samples show strong similarities to carbonaceous chondrites and in particular CI chondrites. The nucleosynthetic isotope compositions of Ryugu overlap with CI chondrites for several elements (e.g., Cr, Ti, Fe, and Zn). In contrast to these isotopes, which are of predominately supernovae origin, s ‐process variations in Mo isotope data are similar to those of carbonaceous chondrites, but even more s‐ process depleted. To further constrain the origin of this depletion and test whether this signature is also present for other s ‐process elements, we report Zr isotope compositions for three bulk Ryugu samples (A0106, A0106‐A0107, C0108) collected from the Hayabusa 2 mission. The data are complemented with that of terrestrial rock reference materials, eucrites, and carbonaceous chondrites. The Ryugu samples are characterized by distinct ⁹⁶ Zr enrichment relative to Earth, indicative of a s ‐process depletion. Such depletion is also observed for carbonaceous chondrites and eucrites, in line with previous Zr isotope work, but it is more extreme in Ryugu, as observed for Mo isotopes. Since s ‐process Zr and Mo are coupled in mainstream SiC grains, these distinct s‐ process variations might be due to SiC grain depletion in the analyzed materials, potentially caused by incomplete sample digestion, because the Ryugu samples were dissolved on a hotplate only to avoid high blank levels for other elements (e.g., Cr). However, local depletion of SiC grains cannot be excluded. An alternative, equally possible scenario is that aqueous alteration redistributed anomalous, s ‐process‐depleted, Zr on a local scale, for example, into Ca‐phosphates or phyllosilicates.

Magnetic resonance imaging (MRI) techniques have emerged as powerful tools for unraveling the pathophysiology of rare diseases, mainly due to their pivotal role in early diagnosis, disease characterization, and treatment monitoring in a non-invasive manner. In this chapter, we will review two essential MRI tools used for studying and evaluating the pathophysiology of Allan-Herndon-Dudley Syndrome or MCT8 deficiency, a rare disease caused by inactivating mutations in the SLC16A2 gene, encoding for the thyroid hormone-specific transmembrane transporter MCT8. These two MRI techniques are time-of-flight magnetic resonance angiography (TOF-MRA) and diffusion tensor imaging (DTI).

The Pacific islands and Island Southeast Asia have experienced multiple waves of human migrations, providing a case study for exploring the potential of ancient microbiomes to study human migration. We perform a metagenomic study of archaeological dental calculus from 102 individuals, originating from 10 Pacific islands and 1 island in Island Southeast Asia spanning ~3000 years. Oral microbiome DNA preservation in calculus is far higher than that of human DNA in archaeological bone, and comparable to that of calculus from temperate regions. Oral microbial community composition is minimally driven by time period and geography in Pacific and Island Southeast Asia calculus, but is found to be distinctive compared to calculus from Europe, Africa, and Asia. Phylogenies of individual bacterial species in Pacific and Island Southeast Asia calculus reflect geography. Archaeological dental calculus shows good preservation in tropical regions and the potential to yield information about past human migrations, complementing studies of the human genome.

Soils play a central role in global biogeochemical cycles and host plants and invertebrates whose engineering activities mainly occur in the upper soil layers, the so-called humipedon. This latter is the critical zone where most chemical, physical, and biological ecosystem processes arise. This chapter overviews the main definitions and concepts (diagnostic horizon, humus system, humus form) and functional approaches to humipedon intimately linked to ecosystem engineers, mainly plant roots and earthworms. Biological activities are decisive in integrating organic matter and forming soil aggregates and galleries. We highlight the relevance of studying humus forms based on field observations in various environments (grasslands, forests, mountains, floodplains) and pioneer ecosystems and underline that more research is needed on the role played by earthworms in the evolution of terrestrial biomes.

Pyrrolizidine alkaloids (PAs) are a structurally diverse group of heterocyclic specialized metabolites characterized by a core structure comprising a hexahydro‐1H‐pyrrolizine. PAs are synthesized through two main pathways. In plants, assembly occurs via a homospermidine synthase, and in bacteria, through combined action of a nonribosomal peptide synthetase and a Baeyer–Villiger monooxygenase. While the toxic properties of plant‐derived PAs and their prevalence in animal and human foods have been extensively studied, the biological roles and biosynthesis of more complex bacterial PAs are not well understood. Here, we report the identification and characterization of a bacterial biosynthetic gene cluster from Xenorhabdus hominickii, xhpA‐G, which is responsible for producing the PA pseudo‐dimer pyrrolizwilline. Analysis of X. hominickii promoter exchange mutants together with heterologous expression of xhpA‐G in E. coli, revealed a set of pathway intermediates, two of which were chemically synthesized, as well as multiple derivatives. This information was leveraged to propose a detailed biosynthetic pathway to pyrrolizwilline. Furthermore, we have characterized the hydrolase XhpG, the key enzyme in the conversion of the pathway intermediate pyrrolizixenamide to pyrrolizwilline, using X‐ray crystallography and small‐angle X‐ray scattering (SAXS).

In modern human societies, social interactions and pro-social behaviours are associated with better individual and collective health, reduced mortality, and increased longevity. Conversely, social isolation is a predictor of shorter lifespan. The biological processes through which sociality affects the ageing process, as well as healthspan and lifespan, are still poorly understood. Unveiling the physiological, neurological, genomic, epigenomic, and evolutionary mechanisms underlying the association between sociality and longevity may open new perspectives to understand how lifespan is determined in a broader socio/evolutionary outlook. Here we summarize evidence showing how social dynamics can shape the evolution of life history traits through physiological and genetic processes directly or indirectly related to ageing and lifespan. We start by reviewing theories of ageing that incorporate social interactions into their model. Then, we address the link between sociality and lifespan from two separate points of view: (i) considering evidences from comparative evolutionary biology and bioanthropology that demonstrates how sociality contributes to natural variation in lifespan over the course of human evolution and among different human groups in both pre-industrial and post-industrial society, and (ii) discussing the main physiological, neurological, genetic, and epigenetic molecular processes at the interface between sociality and ageing. We highlight that the exposure to chronic social stressors deregulates neurophysiological and immunological pathways and promotes accelerated ageing and thereby reducing lifespan. In conclusion, we describe how sociality and social dynamics are intimately embedded in human biology, influencing healthy ageing and lifespan, and we highlight the need to foster interdisciplinary approaches including social sciences, biological anthropology, human ecology, physiology, and genetics.

Osteoderms, bone plates in the skin, are widely but discontinuously distributed across the phylogeny of tetrapods. This and their pronounced morphological disparity has inspired many hypotheses on possible osteoderm functions. Most of these have not been systematically studied or summarised based on the published disparate literature. We provide here a comprehensive overview of the current state of knowledge in this field with a focus on extant non‐avian reptiles. We also discuss functions in other extant osteoderm‐bearing taxa and those inferred from the fossil record. The hypotheses are categorised into protection, lifestyle and locomotion, physiology, and visual functions. A comprehensive overview of future directions in this field is provided. With this review, we hope to encourage future research to investigate the functional aspect of osteoderms. This might inspire biomimetics and shed light on the role that osteoderm expression may have played in shaping present‐day biodiversity.

Although the split of coelacanths from other sarcopterygians is ancient, around 420 million years ago, the taxic diversity and the morphological disparity of the clade have remained relatively low, with a few exceptions. This supposedly slow evolutionary pace has earned the extant coelacanth Latimeria the nickname “living fossil”. This status generated much interest in both extinct and extant coelacanths leading to the production of numerous anatomical studies. However, detailed descriptions of extinct taxa are made difficult due to the quality of the fossil material which generally prevents fine comparisons with the extant Latimeria. Here we describe a new genus and species of coelacanth, Graulia branchiodonta gen. et sp. nov. from the Middle Triassic of Eastern France, based on microtomographical imaging using synchrotron radiation. Through exquisite 3D preservation of the specimens, we reconstructed the skeletal anatomy of this new species at an unprecedented level of detail for an extinct coelacanth, and barely achieved for the extant Latimeria. In particular, we identified a well-developed trilobed ossified lung whose function is still uncertain. The skeletal anatomy of G. branchiodonta displays the general Bauplan of Mesozoic coelacanths and a phylogenetic analysis resolved it as a basal Mawsoniidae, shedding light on the early diversification of one of the two major lineages of Mesozoic coelacanths. However, despite its exquisite preservation, G. branchiodonta carries a weak phylogenetic signal, highlighting that the sudden radiation of coelacanths in the Early and Middle Triassic makes it currently difficult to detect synapomorphies and resolve phylogenetic interrelationships among coelacanths in the aftermath of the great Permo-Triassic biodiversity crisis.

Many organisms inhabiting the interface between land and sea have evolved biological clocks corresponding to the period of the semilunar (14.77 days) or the lunar (29.53 days) cycle. Since tidal amplitude is modulated across the lunar cycle, these circasemilunar or circalunar clocks not only allow organisms to adapt to the lunar cycle, but also to specific tidal situations. Biological clocks are synchronized to external cycles via environmental cues called zeitgebers. Here, we explore how light at night sets the circalunar and circasemilunar clocks of Clunio marinus, a marine insect that relies on these clocks to control timing of emergence. We first characterized how moonlight intensity is modulated by the tides by measuring light intensity in the natural habitat of C. marinus. In laboratory experiments, we then explored how different moonlight treatments set the phase of the clocks of two C. marinus strains, one with a lunar rhythm and one with a semilunar rhythm. Light intensity alone does not affect the phase of the lunar rhythm. Presenting moonlight during different 2-h or 4-h windows during the night shows that (1) the required duration of moonlight is strain-specific, (2) there are strain-specific moonlight sensitivity windows and (3) timing of moonlight can shift the phase of the lunar rhythm to stay synchronized with the lowest low tides. Experiments simulating natural moonlight patterns confirm that the phase is set by the timing of moonlight. Simulating natural moonlight at field-observed intensities leads to the best synchronization. Taken together, we show that there is a complex and strain-specific integration of intensity, duration and timing of light at night to precisely entrain the lunar and semilunar rhythms. The observed fine-tuning of the rhythms under natural moonlight regimes lays the foundation for a better chronobiological and genetic dissection of the circa(semi)lunar clock in C. marinus.

Predicting animal population trajectories into the future has become a central exercise in both applied and fundamental ecology. Because demographic models classically assume population closure, they tend to provide inaccurate predictions when applied locally to interconnected subpopulations that are part of a larger metapopulation. Ideally, one should explicitly model dispersal among subpopulations, but in practice this is prevented by the difficulty of estimating dispersal rates in the wild. To forecast the local demography of connected subpopulations, we developed a new demographic model (hereafter, the two‐scale model) that disentangles two processes occurring at different spatial scales. First, at the larger scale, a closed population model describes changes in metapopulation size over time. Second, total metapopulation size is redistributed among subpopulations, using time‐varying proportionality parameters. This two‐step approach ensures that the long‐term growth of every subpopulation is constrained by the overall metapopulation growth rate. It implicitly accounts for the interconnectedness among subpopulations and avoids unrealistic trajectories. Using realistic simulations, we compared the performance of this new model with that of a classical closed population model at predicting subpopulations' trajectories over 30 years. While the classical model predicted future subpopulation sizes with an average bias of 30% and produced predictive errors sometimes >500%, the two‐scale model showed very little bias (<3%) and never produced predictive errors >20%. We also applied both models to a real dataset on European shags (Gulosus aristotelis) breeding along the Atlantic coast of France. Again, the classical model predicted highly unrealistic growths, as large as a 200‐fold increase over 30 years for some subpopulations. The two‐scale model predicted very sensible growths, never larger than a threefold increase over the 30‐year time horizon, which is more in accordance with this species' life history. This two‐scale model provides an effective solution to forecast the local demography of connected subpopulations in the absence of data on dispersal rates. In this context, it is a better alternative than closed population models and a more parsimonious option than full‐dispersal models. Because the only data required are simple counts, this model could be useful to many large‐scale wildlife monitoring programs.

A new species of the Caribbean genus Cyrtopholis Simon, 1892, Cyrtopholis montserrat sp. nov. is described from the United Kingdom Overseas Territory (UKOT) of Montserrat, based on both sexes. Cyrtopholis femoralis Pocock, 1903 is redescribed from the holotype male with the first figures of the genitalia of this Montserrat endemic spider presented. The endemic Saint Barthélemy species Cyrtopholis antillana Thorell, 1894 stat. rev. is revalidated from synonymy with Cyrtopholis bartholomaei (Latreille, 1832) and non-type specimens of both sexes are described and diagnosed. Cyrtopholis innocua (Ausserer, 1871), C. intermedia (Ausserer, 1875), C. ischnoculiformis (Franganillo, 1926), and C. obsoleta (Franganillo, 1935) are proposed as nomina dubia, and Cyrtopholis respinus Franganillo, 1935 is confirmed as a nomen nudum.

UnambiguousPinaceae taxa are described from the Late Jurassic onwards. This fossil record does not, however, match the molecular estimates of deep divergence within Pinaceae. In recent years, new anatomical observations and revisions have reassigned several species of Schizolepis Braun to the emended genus Schizolepidopsis Doweld, 2001 Emend. Domogatskaya Et Herman . This genus is currently regarded as an early representative of Pinaceae, notably sharing bisporangiate scales, winged seeds, and a more or less constricted cone with scales arranged helically around the axis. This would strongly push the earliest Pinaceae to the early Mesozoic or even the latest Paleozoic. Here, we describe an ovulate cone from the Lower Jurassic of Belgium. Despite its partial preservation, the use of micro-CT allowed the reconstruction of its morphology in details. This reconstruction highlights several characters (ovulate cone with helically arranged scales, constrained, bilobed and bisporangial scales with probable winged seeds) diagnostic of the genus Schizolepidopsis , and constituting a new species, which we name Schizolepidopsis gerriennei sp. nov. This description emphasizes several anatomical characters previously rarely noted for this genus. This ovulate cone represents the first occurrence of this genus in the Early Jurassic of Western Europe, which further completes the picture of its distribution and diversity and supports a much deeper origin of Pinaceae that usually conceived.

The 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.

Infant carrying and more generally load carrying may impact bipedal locomotion and thus the energy cost of the daily activities, in living people but also in our ancestors. In order to improve our knowledge of infant carrying strategies we investigate the biomechanics of infant carrying in a non-mechanised group. The Qashqai are nomadic people who still carry loads and infants habitually without any daily assistance in varied natural environments. Our analysis focuses on the sagittal kinematics using a high-speed camera (joint angles, speed, position of the centre of mass) and kinetics (ground reaction forces and displacement of the centre of mass) using a six-degree of freedom force plate. We assessed the unloaded and loaded (infant) walking of 26 Qashqai women, living in the Fars province (Iran). The results demonstrate that different mechanisms of walking exist that are related to the mode of carrying and the weight of the infant, by which step length, walking speed and the lower limb angles are not affected. The displacement of the total centre of mass remains unchanged. This supports the hypothesis that the Qashqai have developed mechanisms of load carrying that limit the increase in energy consumption. This could be related to the usual high level of daily activity.

Accurate taxonomic classification of deep-sea taxa is often impeded by the presence of highly morphologically similar but genetically distinct species. This issue is particularly pronounced in the isopods of the deep-sea family Macrostylidae, which exhibit remarkably low morphological variation despite significant genetic diversity. In this study, we present the first application of geometric morphometric techniques to 41 specimens across five species of deep-sea macrostylid isopods collected from Icelandic waters. Our results suggest that geometric morphometric techniques can effectively discriminate between macrostylid species. These techniques, hence, promise to be an important addition to the toolset of macrostylid taxonomists.

During the sixth millennium bce, the first farmers of Central Europe rapidly expanded across a varied mosaic of forested environments. Such environments would have offered important sources of mineral-rich animal feed and shelter, prompting the question: to what extent did early farmers exploit forests to raise their herds? Here, to resolve this, we have assembled multi-regional datasets, comprising bulk and compound-specific stable isotope values from zooarchaeological remains and pottery, and conducted cross-correlation analyses within a palaeo-environmental framework. Our findings reveal a diversity of pasturing strategies for cattle employed by early farmers, with a notable emphasis on intensive utilization of forests for grazing and seasonal foddering in some regions. This experimentation with forest-based animal feeds by early farmers would have enhanced animal fertility and milk yields for human consumption, concurrently contributing to the expansion of prehistoric farming settlements and the transformation of forest ecosystems. Our study emphasizes the intricate relationship that existed between early farmers and forested landscapes, shedding light on the adaptive dynamics that shaped humans, animals and environments in the past.