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Throughout history, humans have had a complex relationship with lions, both reverencing and fearing them. Interactions between Neanderthals and cave lions ( Panthera spelaea ) remain poorly documented due to the scarcity of direct evidence. This study examines the selective use of cave lion bones by Neanderthals to determine whether this behaviour was driven by practical, functional, or symbolic factors, through a detailed zooarchaeological analysis. Previous studies highlighted Neanderthals’ skinning and butchering of cave lions, yet new discoveries at Scladina Cave (Belgium) offer deeper insights into this relationship. Dated to the end of the Saalian, the faunal assemblage provides the earliest evidence of bone tools crafted from cave lion remains. A tibia was deliberately processed into multifunctional tools, initially serving as an intermediate tool before being repurposed as retouchers. Proteomic analysis applied on the remains, confirmed the specific identification. These findings reveal that Neanderthals not only competed with but actively utilized cave lions for practical purposes, indicating complex ecological and behavioral interactions. Relationships between pre-humans and large predators, rooted in the Middle Pleistocene, suggest a strategic exploitation of carnivore remains. However, opportunistic procurement cannot be entirely ruled out as a potential factor influencing animal choice in tool production. The intentional transformation of lion bones into functional tools highlights Neanderthals’ cognitive skills, adaptability, and capacity for resource utilization beyond their immediate survival needs.

Speleothems are secondary mineral structures typically found in karstic caves and usually composed of calcite or aragonite. Despite being naturally white, some might exhibit unusual colors, such as blue, black, red, yellow or green. The causes of these exceptional colorations are poorly understood, especially for green speleothems, which are barely reported. Here we describe the occurrence of the green Ni-bearing serpentine nepouite in green aragonite and calcite speleothems, in the Aven du Marcou (Hérault, France). Nepouite is mainly found as flat lamellar crystals in the outer rim of green speleothems and crystallized alongside radially grown aragonite crystals. This supports nepouite beginning to crystallize recently, due to a change in the chemical composition of the water. Nepouite also exhibits extensive substitution between Ni, Mg and Zn. The various elements responsible for nepouite precipitation are thought to come from the weathering of pyrite crystals in the overlying rocks, which is consistent with the pH conditions of the cave and the Al-free composition of nepouite. This study explains the crystallization mechanisms and stability conditions of silicate minerals in colored caves.

Spring water geochemistry is applied here to evaluate the geothermal potential in Rhenohercynian fold and thrust belt around the deepest borehole in Belgium (Havelange borehole: 5648 m MD). Fifty springs and (few) wells around Havelange borehole were chosen according to a multicriteria approach including the hydrothermal source of “Chaudfontaine” (T ≈ 36 °C) taken as a reference for the area. The waters sampled, except Chaudfontaine present an in-situ T range of 3.66–14.04 °C (mean 9.83 °C) and a TDS (dry residue) salinity range of 46–498 mg/L. The processing methods applied to the results are: hierarchical clustering, Piper and Stiff diagrams, TIS, heat map, boxplots, and geothermometry. Seven clusters are found and allow us to define three main water types. The first type, locally called “pouhon”, is rich in Fe and Mn. The second type contains an interesting concentration of the geothermal indicators: Li, Sr, Rb. Chaudfontaine and Moressée (≈5 km East from the borehole) belong to this group. This last locality is identified as a geothermal target for further investigations. The third group represents superficial waters with frequently high NO3 concentration. The application of conventional geothermometers in this context indicates very different reservoir temperatures. The field of applications of these geothermometers need to be review in these geological conditions.

Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma), and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine) branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25) from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ) surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma.

Non-convergence in small-sample structural equation modeling (SEM) is frequently driven by localized pathologies in the sample covariance matrix—specific covariance patterns that, for a given model specification, substantially elevate the risk of non-convergence. We propose a diagnose–localize–shrinkage framework in which a machine learning classifier predicts SEM non-convergence and SHAP values localize the covariance pairs that drive this prediction. Sample covariance matrices are generated independently of the fitted SEM and modified through controlled pathology injection. A fixed SEM is then fitted to each matrix, and the resulting convergence status is used as the prediction target. The classifier is trained on the unique off-diagonal elements of the corresponding correlation matrix. The SHAP-identified covariance pairs are then used to construct a local shrinkage step toward a well-conditioned model-based target matrix to evaluate whether SEM convergence can be restored with limited distortion of the original covariance pattern. We demonstrate the proposed method using an illustrative example.