This work describes and discusses Permian ammonoid faunas collected in two stratigraphic sections from the Las Delicias Formation of Coahuila state, northern Mexico. The taxa identified comprise 18 species, including Demarezites quirozii new species, as well as Mexicoceras smithi (Miller and Furnish, 1940), a variety of Mexicoceras guadalupense (Girty, 1908) here upgraded to specific status. The systematic analysis of the species found allowed us to recognize two middle Permian faunal zones, represented in ascending order by the Waagenoceras dieneri-Adrianites elegans Biozone from the Wordian and the Timorites schucherti-Cibolites uddeni Biozone from the Capitanian. Thus, the relative age of the Las Difuntas-18 section is established as Wordian (middle Guadalupian), whereas the Las Manuelas I section is Wordian–Capitanian (middle–upper Guadalupian). Both ammonoid zones are correlated with those recorded in Guadalupian outcrops from the southern USA, northeastern Japan, and southern China. This faunal resemblance between Mexican ammonoids and those taxa reported in these regions (USA, Japan, and China) supports the proposal that during the middle Guadalupian there was a marine corridor through the Panthalassa Ocean, which could have connected the Paleotethys and North American regions. It should be noted that ammonoids of both studied sections from the Las Delicias Formation were correlated better with West Texas (USA) and British Columbia (Canada) faunas, which are included in the North American Realm.

UUID: https://zoobank.org/60c6c43c-6536-4fbf-a372-c610bec86626

San Sebastián Bay, in southern South America, is an emblematic area because it represents a conflict of interest between the conservation of migratory birds and marine species and the exploitation of hydrocarbons. Given the little information available about the intertidal benthic communities in this bay, this study aims to analyse shell assemblages recovered from the beach, examining drilling and crushing predation on mollusc shells. Two bivalves, Darina solenoides and Mactra fuegiensis, are being preyed upon by three potential drilling predators: the naticid Falsilunatia limbata and the muricids Xymenopsis muriciformis and Trophon geversianus. The intensity of drilling predation was high in both bivalve prey, being higher in M. fuegiensis (27.4%) than in D. solenoides (18.8%). Additionally, there was no preference observed for a particular prey size and there was also no significant correlation between the size of the prey and the predator. However, site selectivity indicated that the predator showed a preference for the central sector in D. solenoides and the umbonal sector in M. fuegiensis, that could be explained by the life modes of both prey and how they are manipulated by their predators. Finally, regarding crushing predation, the shell condition of a significant number of muricids indicates damage most probably caused by decapod crabs. This work provides valuable insights into the biotic interactions within the intertidal communities of San Sebastián Bay, located in the cold-temperate Magellanic Region. It highlights the necessity for continued research and monitoring, particularly in an already conflictive context aggravated by climate change.

We developed a cloud microphysics parameterization for the icosahedral nonhydrostatic modeling framework (ICON) model based on physics-informed machine learning (ML). By training our ML model on high-resolution simulation data, we enhance the representation of cloud microphysics in Earth system models (ESMs) compared to traditional parameterization schemes, in particular by considering the influence of high-resolution dynamics that are not resolved in coarse ESMs. We run a global, kilometer-scale ICON simulation with a one-moment cloud microphysics scheme, the complex graupel scheme, to generate 12 days of training data. Our ML approach combines a microphysics trigger classifier and a regression model. The microphysics trigger classifier identifies the grid cells where changes due to the cloud microphysical parameterization are expected. In those, the workflow continues by calling the regression model and additionally includes physical constraints for mass positivity and water mass conservation to ensure physical consistency. The microphysics trigger classifier achieves an F1 score of 0.93 on classifying unseen grid cells. The regression model reaches an $ {R}^2 $ score of 0.72 averaged over all seven microphysical tendencies on simulated days used for validation only. This results in a combined offline performance of 0.78. Using explainability techniques, we explored the correlations between input and output features, finding a strong alignment with the graupel scheme and, hence, physical understanding of cloud microphysical processes. This parameterization provides the foundation to advance the representation of cloud microphysical processes in climate models with ML, leading to more accurate climate projections and improved comprehension of the Earth’s climate system.

Although the limits of life under individual extremes have been extensively studied, systematic experiments to quantify how combined extremes set the limits to life are lacking. We investigated the combined effects of extremes in temperature, salinity (NaCl) and pH on the growth limits of the marine bacterium Halomonas hydrothermalis, to test the hypothesis that limits to growth under combinations of the extremes establish a more restricted niche than the individual extremes. We show that the combination of supra-optimal temperature, pH and NaCl act synergistically in defining the limits of growth under multiple extremes. Although at optimal growth temperatures (30°C) maximum growth was achieved at pH 7, the maximum temperature limit of 43°C was achieved at pH 8. Under these conditions, the maximum NaCl concentration limit was 6.58% (wt/vol). Decreasing the temperature to 42 and 41/40°C increased the salinity limit to 7.01 % and 8.24 %, respectively. These data show that multiple extremes restrict the limits to growth of this organism to a greater extent than individual extremes and show how natural environments with extremes of temperature, pH and salinity could have restricted microbial diversity, or be uninhabitable, even when each individual extreme lies within the bounds of known microbial growth. These data imply that ‘maps’ of the limits to the biosphere based on laboratory-derived individual extremes may over-exaggerate growth limits in natural environments, which are rarely subject to single extremes, highlighting the need for multi-parameter analyses.

Recent ice cores from the Allan Hills, a blue ice area in Antarctica, are nearly 3 million years old. These cores extend ice core chronologies, enabling new insight into key climate periods such as the Mid-Pleistocene Transition. The interpretation of these climate records is complex because of the disturbed stratigraphy in this ice. Here, we present a new three-dimensional multitrack electrical conductivity measurement method (3D ECM) to resolve layer structure. We demonstrate this technique on a cumulative 60 m of two large-diameter (241 mm) ice cores, ALHIC2201 and ALHIC2302. Measurements were taken on the upper section of both cores due to better ice core quality in this shallow ice. We find well-defined and dipping layering in both cores, averaging 29° in ALHIC2201 and 69° in ALHIC2302 from horizontal. We observe a slight decrease in dip with depth in both cores, although it only achieves statistical significance in ALHIC2302. We discuss how this new method can be applied to enable accurate, high-resolution multi-proxy record development even in ice cores with steeply dipping layers. 3D ECM improves interpretation of blue ice area cores by providing accurate, non-destructive constraints on stratigraphy.

This study investigates the accumulation of glycogen, amino acids, and fatty acids in male Mytilus coruscus during different stages of gonadal development and explores their relationships with reproductive processes. Glycogen levels were highest during the resting phase, decreasing progressively during the proliferation and maturation phases. A positive correlation was observed between glycogen and carbon content, indicating a close association between energy storage and metabolic processes. Amino acid content, particularly essential amino acids (EAAs), increased during gonadal development, reflecting the higher demand for protein synthesis and cellular metabolism. Branched-chain amino acids (BCAAs) such as isoleucine, leucine, and lysine were key in activating protein synthesis and supporting gametogenesis. Non-essential amino acids like aspartic acid, glutamic acid, and glycine also accumulate, supporting cellular function and reproductive regulation. Fatty acids, especially unsaturated fatty acids (UFAs) and polyunsaturated fatty acids (PUFAs), progressively accumulated in the testes, highlighting their role in energy supply and membrane integrity during gametogenesis. Phosphorus (P) accumulated in parallel with fatty acids, supporting DNA and RNA synthesis, energy metabolism, and cell membrane function. This study emphasizes the crucial role of these biochemical components in supporting gonadal development in male M. coruscus, providing insights into the metabolic pathways involved in marine bivalve reproduction.

Halloysite nanotubes (HNTs) face significant challenges in their application due to their aggregation, poor dispersion and high hydrophilicity, which limit their integration into polymer matrices. This study introduces a novel functionalization strategy for Algerian HNTs, targeting their inner and outer surfaces with triethoxy(octyl)silane (OTES) for silanization and caffeic acid (CA) for lumen loading. Comprehensive characterization techniques were used to analyse pristine and OTES-modified HNTs (O-HNTs) and CA-loaded HNTs (CA-HNTs) to evaluate the impacts of both selective agents, which successfully altered the structural, textural, chemical, morphological and thermal HNTs properties. The crystalline structure and changes in crystallite size following surface modification were determined using X-ray diffraction analysis. Brunauer–Emmett–Teller analysis showed that the surface area of O-HNTs increased to 74 m2 g–1 compared to 54 m2 g–1 for HNTs, whereas CA-HNTs experienced a surface area decrease to 42 m2 g–1 owing to pore obstruction, with the pore sizes shifting to 10–12 nm for O-HNTs and to 16 nm for CA-HNTs. Fourier-transform infrared spectroscopy and X-ray fluorescence confirmed effective surface modification through the achievement of successful chemical bonding and a shift in the elemental composition. Morphological analysis using scanning electron microscopy revealed considerable morphological changes in both treatments, and thermogravimetric analysis demonstrated that the thermal stability of HNTs modified with CA was improved, with a higher decomposition peak at 520°C. These modifications effectively improved the dispersion, thermal stability and compatibility of the HNTs, highlighting the potential of the modified Algerian HNTs as promising green nanofillers in polymer nanocomposite applications, such as active packaging and thermal insulation coatings.