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Abstract: During the Paleogene, bees diversified extensively after expanding from tropical regions into northern forests surrounding the future Baltic Sea, evolving alongside diverse angiosperms. Most fossil bee diversity is preserved in amber, which captures morphology but rarely behavior or ecology. Using synchrotron X-ray imaging, we describe a new leaf-cutter bee species, †Protolithurgus acarophorus sp. nov., from two specimens in Baltic amber. This is only the second known record of the extinct tribe †Protolithurgiini, which displays both ancestral and derived megachilid traits. The holotype preserves exceptional anatomical detail and reveals ecological insights, including compacted floral rewards in the hind-leg scopa, a pollen-carrying strategy rare in living Megachilidae. We also document the first fossil bee-mite association, suggesting unspecialized kleptoparasitic interactions, and reconstruct thoracic musculature dimensions. Together, these findings provide rare evidence of the foraging ecology, parasite relationships, and biomechanics of the earliest leaf-cutter bees.

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Abstract: This manuscript describes a workflow for automated data collection that uses a robotic arm for sample exchange, significantly improving data collection efficiency. The setup, implemented for synchrotron X-ray imaging at the Diamond Light Source (DLS) I13-2, Imaging beamline, utilizes a robot to achieve high-throughput serial tomography (3D) or imaging (2D). At present, for many experiments, the time required for manual sample exchange and alignment is comparable to, or even exceeds, the duration of the tomography scan itself. To maximize the efficient use of available beam time and increase experimental throughput, automating sample exchange and alignment is essential. Using the robot as a sample changer can increase throughput by at least 4-10 times compared to manual procedures, depending on which pixel size is chosen. With the Diamond II machine and the I13L beamlines Operando Coherent TOmography and Ptychographic Imaging (OCTOPI) upgrades, the increased X-ray flux will further reduce the experimental scan times, making the system even more efficient. Furthermore, the automation enables remote data collection, including an optional mail-in service for users. Automated sample centering allows fully unattended scanning, which can be performed remotely. This represents a unique and innovative feature of the system. This manuscript describes the complete procedure, including sample preparation, mounting on specialized holders, transport to the beamline, and placement on the dedicated trays for robotic sample exchange. The procedure for automated sample centering and the subsequent tomography reconstruction pipeline are presented.

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Abstract: Vision is one of the most important senses used by animals and contributes to fundamental behaviors, including foraging, navigation, and mate detection and selection.1 Although much is known about how eye position and orientation correlate to ecology in the context of binocularity,2 animals with multipartite visual systems (more than two eyes) remain comparatively neglected. Spiders are highly successful predators that occupy a range of ecological niches and usually possess eight eyes. Here, we use three-dimensional geometric morphometrics and evolutionary modeling to test whether eye positions, orientations, and interocular angles correlate with hunting strategies in 52 species across the spider phylogeny. We demonstrate that eye configurations diversified from an ancestral medial cluster, as seen in modern trapdoor spiders, to a halo-like configuration in orb-weavers, and to the frontal clustering of eyes in several members of derived spider lineages. We show that visual hunters have the highest disparity and evolutionary rates in the configuration of their eyes but display a distinct morphological signature with multiple eye pairs concentrated at the front of the carapace. Moreover, we quantify the extent to which eye configuration is modular and show that the position and orientation of the eye pairs evolve semi-independently of each other. Our findings demonstrate that modularity in the spider visual system facilitates not only the specialization of individual eyes but also the whole architecture of the visual system, in line with different hunting strategies, body plans, and ecological niches.

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Abstract: The cellular basis for site-specific inflammation remains unclear. In human fingers, proximal interphalangeal (PIP) joints are preferentially affected by inflammatory arthritis, whereas distal interphalangeal joints are spared, providing a model to investigate the predilection of inflammation to distinct sites. Here we combine single-cell RNA sequencing, imaging and X-ray tomography to examine cellular composition, spatial organization and structure of finger joints during fetal development. PIP joints had a larger synovial volume and were enriched for PI16+ ‘universal’ fibroblasts. These cells were located in perivascular regions and at developing tendon–ligament interfaces. PI16+ fibroblasts exhibited both a shared inflammatory and cell-type-specific response to cytokine stimulation, suggesting that the combination of their spatial location and transcriptional responses promote inflammation. We suggest that differences in the stoichiometry of mesenchymal cells established in utero, including the key role of PI16+ fibroblasts, is a general principle that drives inflammation susceptibility across tissues.

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Abstract: The biomechanical function of the musculoskeletal system depends on hierarchical structures spanning the molecular to whole-organ scales. In the spine, intervertebral discs (IVDs) must balance flexibility with efficient transfer of load between soft and hard tissues. This relies on a complex mechanical interplay across scales, from mineral nanostructure and pre-strain, through collagen–fibril and fibre-level mechanics, up to tissue microarchitecture and regional variations at the organ level. This thesis explores these interactions using advanced multimodal synchrotron X-ray imaging techniques, capable of probing mechanics across multiple length scales. The first section employs in situ imaging of vertebral endplates to examine how structure relates to mechanical strain across spatial scales. Digital volume correlation (DVC) combined with microarchitectural analysis reveals that high tensile and shear strains play a role in the cartilage to bone transition. Correlative imaging and diffraction show that bone contains narrower mineral nano-crystallites under greater compressive pre-strain compared with calcified cartilage. The second section introduces TomoSAXS, a full-field 3D small-angle X-ray scattering tomography that maps fibril-to-fibre mechanics across the annulus fibrosus in the IVD. This method, combined with in situ mechanical loading and DVC, enables correlative measurements of structure and strain at the organ, tissue, fibre and fibrillar scales. This reveals that collagen fibrillar pre-strain is lamellar-textured and tightly correlated with microscale fibre strain. Fibre strain increases with fibre curvature, and radial strain bridges emerge as critical regulators of local mechanics. Scaling the technique from small animal to human IVDs is demonstrated by utilising high-energy X-rays at a 4th generation synchrotron source. Together, these studies provide an integrated, multiscale view of IVD biomechanics, linking mineral and fibrillar nanostructure to tissue and organ-level function. The methods and insights developed here not only advance our understanding of spinal biomechanics but also offer inspiration for the design of biomimetic materials and orthopaedic implants.