The Antarctic Peninsula is one of the regions in Antarctica that has experienced notable and extensively studied warming since the mid-twentieth century. Meteorological data, although limited and mostly dating back to the International Geophysical Year (1957–1958), reveal dramatic climate changes in both the Antarctic Peninsula and West Antarctica, with the Antarctic Peninsula showing the highest warming trends on the continent. One major manifestation of this warming is the increasing frequency and intensity of extreme warm events. This study utilizes temperature data from the Artigas Antarctic Scientific Base provided by National Weather Service, Uruguayan Institute of Meteorology (INUMET), which have not previously been used or quality-controlled. Data were processed and analysed, and a quality hourly database was built for the period 1 January 1998 to 11 December 2016 for the surface temperature, constructing a complete time series interpolating the data with two other nearby Antarctic stations (C.M.A. Eduardo Frei Montalva and King Sejong). Temperature presented an annual cycle with marked interannual and seasonal variability, with the cold season being the one with the highest variability and the largest anomalies, both positive and negative. No significant trend was found for the monthly mean temperature. A study of warm temperature events was conducted at three points on King George Island, defining warm events and extreme warm events as those in which the mean daily temperature was above the 90th and 99th percentile, respectively, for at least 3 consecutive days. A high frequency of occurrence was found (all years except 2015) mostly in the cold season of the year, and with large interannual variability. In turn, it was found that certain atmospheric dynamics favour the generation of these extreme warm events, and that their occurrence is higher during La Niña years. Although the majority of the extreme warm events occurred during positive phases of the Southern Annular Mode, the statistical correlations were not significant.

Over the past half century, paleobiologists have advanced the estimation of phylogenetic relationships among fossil taxa to explore evolutionary patterns in deep time. This study employs a breadth of phylogenetic analyses, specifically divergence time estimations and character rate evolution, within three blastozoan echinoderm clades: Diploporita, Eublastoidea, and Paracrinoidea. Utilizing reversible jump Markov chain Monte Carlo (rjMCMC) and fossilized birth–death (FBD) models, we investigated evolutionary rates through anatomical subunit partitioning. Results suggest similar rates among the three groups, although Paracrinoidea exhibits elevated rates in several anatomical subunits. The inferred trees largely agree with other recently published analyses, in that the current taxonomy of the group does not reflect true evolutionary relationships. Thus, this study adds to a growing body of literature that highlights the need to revise echinoderm taxonomy. We tested different clock models for each group and found that model choice had strong effects on resulting trees; our findings suggest linked clocks (i.e., the same clocks for all character partitions) had more support than unlinked clocks (i.e., different clocks for different character partitions). These findings indicate a need to carefully consider model choice and rates of evolution when utilizing these types of analyses.

Garnet-bearing silicic volcanic rocks are rare in fossil orogens and usually record a transient stage from regional compression to extension. This study reports newly identified 839 ± 3 Ma garnet-bearing dacitic volcanic rocks associated with the Fuchuan ophiolite complex (FOC) in the eastern Jiangnan Orogen (JO), Southeast China. The presence of these unusual rocks provides new constraints on the late Neoproterozoic tectonic evolution of the orogen.

The garnet-bearing dacitic volcanic rocks of the garnets are weakly peraluminous and exhibit trace element and Nd isotopic signatures similar to those of post-orogenic, strongly peraluminous granites in the eastern JO, indicating a similar crustal source. The garnets are almandine-rich (76–79 wt%) and characterized by low CaO (<2.5 wt%), MnO (<2.6 wt%) and TiO2 (<0.1 wt%), consistent with garnets in peraluminous S-type volcanic rocks globally. Integrated petrological, geochemical and zircon Hf isotopic evidence indicates that the primary magma originated from partial melting of a heterogeneous lower-crustal source, comprising both juvenile basaltic and ancient pelitic components. High zircon saturation temperatures (>900°C) further imply the heating of coeval underplating mantle-derived mafic magma, analogous to the mechanism forming ‘hot granites’.

Integrating our findings with regional geology, we propose that the garnet-bearing dacitic volcanic rocks associated with the FOC formed in an ensialic back-arc basin along the southeastern margin of the Yangtze Craton. The occurrence of the garnet-bearing magmatism records the onset of back-arc extension, likely following the ∼880–860 Ma arc–continent collision and subsequent subduction polarity reversal.

We evaluate the systematic position of Shundeagrion cheni Huang, Lia, and Nel, 2024 and transfer it to the odonate suborder Cephalozygoptera and family Dysagrionidae.

Studying social behaviour of mobile and cryptic marine mammals is challenging, particularly for small species like harbour porpoises whom in many areas tend to be challenging to initially spot and then gain repeated observations. Recently, there has been a rise in the number of observations of harbour porpoises occurring in atypical group sizes that are larger than the typical size of two to three individuals. This behaviour, in conjunction with the evolving availability and usability of Unmanned Aerial Vehicle (UAV) technology, is supporting and improving the capture of information on social behaviours. Around Shetland, Scotland, harbour porpoises are sighted from land via opportunistic and systematic surveys year-round with atypical group sizes also observed. To capture information on group size, opportunistic and systematically collected UAV footage were collated and analysed. This revealed sexual approach behaviours in typical group sizes of small groups (two to four individuals), as well as atypical group sizes of medium groups (five to nine individuals), large groups (10 to 19 individuals), and aggregations (≥20 individuals) occur in multiple bays around Shetland. This is the first insight into group sizes and behaviours for the region which was recently designated as an Important Marine Mammal Area (IMMA). Further insight into these social behaviours and group size (e.g. seasonality, site fidelity) could aid harbour porpoise conservation and management within the IMMA and elsewhere.

The suitability of marine limpet shells for radiocarbon dating may depend on potential offsets due to diet and habitat, especially with regard to grazing mollusks on carbonate substrates (Dye 1994; England et al. 2013). A previous study on one grazing limpet species on the coast of Ireland found no offsets from carbonate substrates (Allen et al. 2019), but a similar study from mediterranean coasts found significant offsets on carbonate substrates (Ferguson et al. 2011). We carried out a new study of radiocarbon and stable carbon isotopes, using multiple species of mollusks collected live from the coasts of Gibraltar and Sardinia, from both carbonate and non-carbonate substrates. The 14C results indicate that one species, inhabiting the upper shore, has a significant offset at the carbonate locations. This species, Patella rustica, has adapted to tolerate desiccation and may have biological traits that result in higher metabolic-derived carbon incorporated in its shell. The results of this preliminary study imply that selected species of grazing mollusks are suitable for radiocarbon dating, even in areas of carbonate geology.

Radiocarbon dating by accelerator mass spectrometry (AMS) requires transforming samples into graphite, a step that typically depends on liquid nitrogen and high-purity carrier gases, increasing both cost and operational complexity. We present μGRAPHILINE, a fully automated, modular combustion–graphitization line that removes these dependencies by combining dual-zone combustion with iron–zinc reduction. Performance was evaluated on more than 180 standards and reference materials targets measured on two independent AMS systems. The μGRAPHILINE consistently achieved >90% graphitization yields, stable backgrounds of ∼0.24 pMC (≈48,500 BP), and sample throughput of ∼3.5 hours per target. Reliable operation was demonstrated for a broad sample-size range, from routine 1 mg C down to ∼0.2 mg C, with ion currents sufficient for precise AMS analysis. The system’s automation, modularity, and low memory effect support improved laboratory throughput and operator efficiency. These results indicate that μGRAPHILINE provides a robust and efficient approach to radiocarbon sample preparation with broad potential applications.

Welwitschia mirabilis, a unique gymnosperm native to Namibia and Angola, is a keystone plant species in the Namib Desert. It represents the only extremely long-lived non-clonal plant species occurring under hyperarid desert conditions, yet limited attempts have been made to accurately determine its age. Here, we present radiocarbon dates from a dead, sectioned Welwitschia of moderate size. We find the outer caudex tissue growth to progressively increase in age from the leaf base towards the ground level in this dwarf tree, while the inner cortex tissue becomes younger. Our sampling strategy revealed that the oldest tissue from this Welwitschia, found at the base of the caudex in the middle of the lobe, was dated to 531 ± 20 14C years, suggesting a vertical growth rate of approximately 0.47 to 0.67 mm/year. These findings can serve as a basis for future dating of larger, living individuals.

We investigated the epizoic diatoms colonizing the carapace of the spider crab Hyastenus hilgendorfi inhabiting Lake Timsah in the Suez Canal. A total of 63 individuals, free of macro-epibionts, were examined to assess the diversity, abundance, and seasonal dynamics of their associated diatom communities. A total of 61 diatom taxa belonging to 31 genera were recorded, with raphid pennate diatoms being the most dominant, particularly Navicula lanceolata. Diatom density and diversity exhibited clear seasonal variation, where Summer had the highest richness and Spring the highest cell densities. Overall, males hosted more diatom taxa than females, however, sex-specific differences fluctuated seasonally. The cluster analysis revealed distinct diatom assemblages between sexes and seasons, showing subtle but significant variation in epibiont structure. These findings provide the first detailed characterization of epizoic diatom assemblages on H. hilgendorfi. They suggest that seasonal variations in diatom communities may influence the crab’s camouflage effectiveness by altering biofilm characteristics which facilitate macro-epibiont settlement.

Monitoring snow distribution in alpine terrain is critical for hydrology, avalanche safety, and climate research, yet traditional surveys are costly, hazardous, and spatially sparse. We assess a gondola-mounted, low-cost Light Detection and Ranging (lidar) system (MOLISENS) for repeated snow monitoring in Real-Time Kinematics (RTK)-denied mountain environments. The system fuses lidar, Inertial Measurement Unit (IMU), and standalone Global Navigation Satellite System (GNSS) using a Simultaneous Localization And Mapping (SLAM) algorithm to generate 3D point clouds along a fixed aerial-lift transect at Hoher Sonnblick, Austria. Six winter runs (March 2023) were processed and compared with summer Unmanned Aircraft System (UAS)-photogrammetry. Intra-system repeatability between same-day scans reached centimetre precision (weighted standard deviation 0.010 m; 95% within $\pm$0.006 m), supporting detection of daily to seasonal changes in snow thickness along the route. Absolute agreement with the UAS reference was limited to decimetre scale, primarily due to registration and standalone GNSS uncertainties rather than sensor range noise. Performance degraded over feature-poor snowfields, and manual segment merging was labor-intensive; consequently, quantitative analyses were restricted to well-constrained segments. Despite these limitations, the results demonstrate the feasibility of gondola-mounted lidar for cost-effective, repeatable snow-thickness mapping.

This study provides the first results on the population dynamics of Sphyraena sphyraena (Linnaeus, 1758) in the western Mediterranean. Otoliths and scales reading were used for its age and growth investigation in Eastern coast of Algeria. The monthly evolution in marginal increment data of scales and otoliths revealed that only one annulus is formed per year in February. Fish length and radii of the scales or otoliths were closely correlated. Both methods showed four age groups. ANOVA test (P < 0.05) revealed insignificant differences between both estimates of length at age results. Growth parameters estimated using length-at-age data from both methods confirming the age determination results. The total mortality (Z ), natural mortality (M ), and fishing mortality (F ) were estimated at 1.19 year−1, 0.826 year−1, and 0.363 year−1, respectively. The growth performance index (Ø ) was 2.57. The estimated exploitation ratio (E ) was 0.305. The length–weight relationship is EW = 0.0104 TL2.702, showed that the growth rates were negative allometric. The results revealed the compatibility of otoliths and scales reading for assessment studies of Sphyraena sphyraena .

In Brazil, laws are being adopted prohibiting the use and distribution of non-recyclable plastic bags and encouraging the use of recyclable, biodegradable and bioplastic bags. However, there is no specific standard method in Brazil to inspect the carbon content of bioplastics. This work aims to implement the sample preparation for radiocarbon biogenic fraction determination in bioplastics in the new radiocarbon laboratory at the Federal University of Bahia (LAPA14C-UFBA). Six plastic samples from Brazilian markets with bio-based seals were collected in regular Brazilian markets, four bags and two tubes. All samples were combusted and graphitized in the LAPA14C-UFBA and the graphites were measured at the Radiocarbon Laboratory (LAC-UFF). The biogenic fraction analysis followed the Standard Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis (ASTM D6866-24). Since the bioplastic manufactured in Brazil is derived from sugarcane, a C4 plant where δ13C values are different from those of petroleum-derived plastic, the biogenic fraction was obtained via the isotopic mixture equation. The results showed a robust direct correlation (r=0.998) between the fractions obtained by the two methods, indicating that δ13C analysis can be used, in this case, as an alternative in determining the biogenic fraction of plastics. From the results obtained, four out of the six samples analyzed showed biogenic fraction values below the 51% required by the I’m Green label, with values ranging from 4% to 43%, according to the δ3C and 14C analysis, showing the efficiency of both techniques in determining the biogenic fraction.