Population monitoring provides information on species conservation status. We reassess the status of the southern elephant seal population at Macquarie Island. The number of cows on the isthmus, ~20% of the total population, correlated with counts for the whole island (i.e. they reliably indicate island-wide trends). Cow numbers within the isthmus decreased from ~9400 in 1949 to ~2550 in 2023 at −1.1% year−1, similar to the −0.8% year−1 from 1984 to 2023 when counts were made annually (before 1984, counts were less systematic). This contrasts with all other southern elephant seal populations, which are either stable or increasing. There was also considerable year to year variability (± 350 cows year−1) in the numbers of cows ashore, indicating individuals skipping breeding. Counting errors may contribute to this variability but are unlikely given that the isthmus study area harems are small, typically < 200 cows. We found no link between cow numbers and summer ocean conditions using the Southern Annular Mode as a proxy (i.e. prior to blastocyst implantation), and it remains unclear what is causing this variation. Nonetheless, several other studies have suggested changing prey conditions during the winter are the most likely cause of this overall and ongoing decrease.

Airborne investigations are a keystone for understanding the Antarctic environment across many scientific disciplines. Over the past decade and more, the use of drones has been proposed as a means to enhance this airborne capability. Small quadcopter/multi-rotor drones, typically flown within visual line of sight, have become a well-established and routinely deployed technology. However, larger fixed-wing uncrewed aerial vehicles (UAVs) capable of beyond-visual-line-of-sight missions similar to traditional crewed aircraft have not been routinely deployed. Here, we report on the first deployment of a large (10 m wingspan) UAV for scientific data collection from Rothera Research Station, Antarctica. The platform, a Windracers Ultra, flew 2978 km over 25 missions, collecting a range of scientific observations including visual and hyperspectral imagery, atmospheric turbulence data and gravity and magnetic data. All science missions were carried out beyond visual line of sight and were up to 2.25 h/260 km long. Missions included coordination with and operation alongside crewed aircraft. Our field season has successfully demonstrated that large UAVs can play a significant role in Antarctic data collection, working alongside crewed aviation to improve our understanding of Antarctica.

Submarine landforms in polar fjords provide essential insights into glacier responses to climate change in the Maritime Antarctic. This work aims to reconstruct the groundline of a palaeo-ice stream throughout the Holocene in Admiralty Bay, King George Island. The landforms were investigated using multi-resolution topobathymetric data based on seismic and multibeam surveys. The inner sector features shallow moraine banks and elongated glacial lineations, in contrast to the deeper moraine banks observed in the middle and outer regions of the fjord. Elongated glacial lineations indicate a north-east to south-west ice flow and a wet-based thermal regime. At ~9000 years bp, the grounding line was at the Admiralty Bay fjord’s mouth. In the middle of the fjord, a prominent morainal bank reveals the palaeoglacier’s grounding line. The grounding line significantly changed position after this stillstand in response to climatic variability (Mid-Holocene, at 4500–2800 years bp) and was conditioned by the deep bathymetry. The continued retreat of the ice in the Holocene possibly led to a division of the palaeo-ice stream into outlets or tidewater glaciers. MB7 and MB9 indicate the position of the grounding line during a major stillstand at the end of the inlets. The bedrock topography and fjord geometry influenced the deglaciation pattern of Dobrowolski Glacier in Martel Inlet, and the moraine banks recorded two final major stillstands. The retreat rates in Martel Inlet have increased due to the loss of anchoring points and rising temperatures after the Neoglacial period. The morainal banks present in the proximal environments at Martel Inlet are smaller, discontinuous and spaced, indicating the retreat behaviour in the last 7 decades.

Soft-bottom areas are among the least explored ecosystems in Antarctica. To improve our understanding of these environments, we performed a preliminary assessment of the marine macrobenthic fauna in False Bay, Livingston Island, near Huntress Glacier (South Shetland Islands, Antarctica). Fourteen Van Veen grabs (0.018 m2 area) were deployed at two stations within the bay at depths of 174–210 m. The samples provided values up to 159 556 individuals m-2 within 15 major taxonomic groups. Annelida Polychaeta was predominant (~93%), followed by Ophiuroidea and Bivalvia at the external station and Bivalvia and Amphipoda at the internal site. Maldanid polychaetes, particularly Maldane sarsi antarctica, constituted 84.62–90.74% of the samples. Total biomass was 6673.25 grams of wet weight per square metre, mainly from Ascidiacea, Polychaeta, Holothuroidea and Ophiuroidea. Approximately 12% of the macrofauna inhabited the sediment (epifauna), while 88% lived into the sediments (infauna). Regarding feeding modes, specimens were detritivores (77.91–82.71%), suspension-feeders (7.59–13.37%) and, infrequently, predators (4.07–5.07%) and grazers (4.63–4.65%). According to the compilation of occurrence records in the Southern Ocean, M. sarsi antarctica has a circum-Antarctic distribution. Furthermore, the population of this species in False Bay appears to be stable and undisturbed with a normal distribution in size structure, with a higher proportion of individuals at intermediate sizes (2.85–4.26 cm). This study provides for the first time detailed descriptions of the macrofauna from the soft bottoms of False Bay, representing a preliminary effort to monitor ecological shifts in this critically important and understudied region, which is experiencing rapid environmental changes within Antarctic marine ecosystems.

The pebble crab, Leucisca levigena, was recorded for the first time from the intertidal regions of South Andaman in the Andaman and Nicobar Islands, India. This comes after its holotype was described in 1976 from Western Australia. The species was found on the thallus of the green seaweed, Halimeda opuntia. Notably, the study included the first record of a male specimen, previously absent in its first description. L. levigena is characterized by its slightly concave dorsal carapace with a beaded margin, a raised gastric region extending to the front, and a smooth pterygostomial region. A brief description and illustrations of both the male and female species and a map showing the distribution of Leucisca species around the world are provided. L. levigena confirms its distribution from Western Australia to the Andaman Islands.

The recovery of nearly 250 burials at the El Olivar site provided the opportunity to address questions regarding the groups inhabited coastal settings of the semiarid north of Chile between the 800 and 1540 AD. Stable isotopes of carbon, nitrogen, and oxygen were analyzed from 60 human samples. Radiocarbon (14C) analyses were conducted in 20 samples from camelids and 42 human samples. Subsequently, a sample of 25 individuals exhibiting diagnostic cultural features of the Las Ánimas Cultural Complex (LACC) and the Chilean Diaguita Culture (CDC) was selected for the purpose of assessing differences in their diet and mobility and clarifying their chronology. The δ13C and δ15N values obtained revealed the existence of a small group of individuals (n=6) with a diet based on C3 plants and terrestrial protein, and another major group (n=33) with values compatible with the consumption of C4 plants and marine resources. Four of the six individuals of the small group presented Ánimas diagnostic features, and in the major group were identified both Ánimas and Diaguita individuals. The δ18O values exhibited a similarity between the Ánimas and Diaguita individuals, suggesting coastal-to-inland mobility in both groups. Calibrated 14C dates indicate that El Olivar was occupied for a period of nearly 380 years, spanning between 1150 and 1536 AD, and that between the 1300 and 1400 AD, Ánimas and Diaguita individuals coexisted at El Olivar. These findings call into question the current thought that the CDC emerged from the LACC around 1000 AD, and that both represent different archaeological entities.

Saltmarshes are widely recognized as one of the most productive coastal habitats, and on the Amazon coast, Spartina alterniflora marshes are widespread on both marine and freshwater sites. On the Amazon coast, this ecosystem is subject to a wide array of environmental factors that influence its characteristics and associated macrobenthic fauna. However, few studies have been carried out in Amazonian saltmarshes when compared to others regions worldwide. Therefore, this study characterizes the vertical distribution of macrobenthic fauna in Amazon saltmarshes and their seasonal changes. Vertical stratified samples (0–10 and 10–20 cm) were collected during the rainy (April 2008) and dry seasons (November 2008) in saltmarshes located in an Environmental Protected Area located on the Northern Brazilian Amazon coast (Algodoal-Maiandeua island). The saltmarsh area varied between seasons, being denser and taller in the dry season. A total of 38 macrobenthic taxa were recorded, of which 11 were exclusively found in the dry season. The macrobenthic faunal structure varies among seasons, with higher density and richness in the dry season. Overall, higher densities and richness were found at near-surface layers in both seasons. We suggest that the vertical distribution of the macrobenthic fauna depend on the vegetation density in Amazon saltmarshes, since this vertical distribution is more prominent in the dry season where we observed higher Spartina density and most of the fauna is concentrated near the surface. Therefore, this study provides novel insights into macrobenthic distribution patterns, reinforcing that Amazonian saltmarshes have unique characteristics that strongly influence their distribution.

Genome size (GS) is thought to be a key life-history trait and important for controlling plant distributions and evolutionary dynamics, but a full understanding of GS variation through evolutionary history requires proxy measurements from fossils. Here, we compare two potential GS proxies: guard cell length (GCL) and sporomorph size. We generated GCL and pollen size data from angiosperms growing in the University of Münster Botanical Garden, compiled sporomorph size data from the literature, and related these to GS using phylogenetic regression models. We also fit evolutionary models to the botanical garden data and used a published dataset to validate GCL as a GS proxy. The majority of the analyses conducted revealed a positive relationship between GS and sporomorph size, but in most cases, the explanatory power of the regressions was low. GCL showed a stronger and more consistent relationship with GS, and independent validation of the relationship showed a generally good match between predicted and observed GS. Sporomorph size is not suitable as a cross-taxon GS proxy, but some specific taxa (e.g., Pinus) may contain useful GS information. GCL has much more potential for measuring paleo-GS, but requires further research for us to better understand possible environmental controls on cell size variation.

Four new hemipteran insects are described from the Triassic (Norian) Cow Branch Formation of Virginia and North Carolina (USA), including one pair of isolated wings belonging to Hylicellidae (Hylicelloidea: Cicadomorpha), one complete specimen assigned to a distinctive new genus of Ipsviciidae (Scytinopteroidea: Cicadomorpha), and two heteropterans belonging to unknown families. Only the ipsviciid is preserved with enough morphological detail for systematic study and is herein described as Solitivicia reducta new genus new species due to its highly reduced forewing venation. The peculiar distribution of hemipterans in the Cow Branch Formation, namely the paucity of cicadomorphans and coleorrhynchans which are both otherwise abundant in Triassic deposits, is discussed.

UUID: http://zoobank.org/dbc44e2c-6e3d-4ec6-9912-7b041d6ca2fd

The new damselfly family Shundeagrionidae is proposed for Shundeagrion cheni n. gen. n. sp. from the Paleocene of the Sanshui Basin, South China. This new family is unique in a combination of wing venation characters that are separately encountered in other extant and fossil groups. Together with the extinct groups Dysagrionidae, Sieblosiidae, Whetwhetaksidae, Menatlestidae, Latibasaliidae, Euarchistigmatinae, and Eodysagrioninae, the Shundeagrionidae n. fam. is the eighth major group of Paleogene damselflies with large wings, very long postnodal area, and nodus relatively basally recessed. It confirms that an important diversification occurred worldwide among the damselflies during the Paleocene and Eocene. These relatively ancient groups were progressively replaced by the modern families of large calopterygoid damselflies during the Oligocene and the Miocene, leading to the modern faunas.

UUID: http://zoobank.org/e18cf9dc-c438-484c-b97e-dcc6d63986bd

A previous study of the altitudes of the lowest part of the Upper Cretaceous–Eocene stratigraphic ensemble evidenced for the first time the existence of an east-west elongated dome between N53° and N54° Lat. on the western slope of the Southern Urals. This ridge which is superimposed on the remnants of the Sernovodsk–Abdullino Aulacogen and with the Belaya tear fault was the result of the rejuvenation of these deep basement features; it has been interpreted as a positive flower structure. Slightly to the north, the Southern Urals display a clear bend towards the East. In front of it, detailed microstructural studies show that this curvature was associated with a stress pattern typical of an indentation. Field studies concentrating on the intersection between the flower structure and the Belaya River Valley show (1) that there are two riverbeds more or less superimposed in the same valley, (2) that the older watercourse is offset by small east-west shear zones, (3) that the shear zones are in continuity with the flower structure and (4) that the recent riverbed is not affected by similar offsets. The vertical movements recorded along the Belaya River by geodetic measurements don’t support the existence of a recent activity of the indenter because they are always of a limited extent and associated with karst collapses. This conclusion is supported by the stratigraphic evolution of the fluvial sediments and confirms that the indentation of the Southern Urals did not continue after 10 ka.

Pterotheca Salter, 1853 is an unusual but readily identifiable bellerophontoid gastropod that occurs in the Upper Ordovician to the Llandovery of the lower Silurian in many parts of North America and Europe. Recently, a large collection of Pterotheca was obtained for the first time from the Xiushan Formation of middle Telychian (Llandovery) age in the Hunan Province of South China. This is also the first record of the genus in the low-latitude peri-Gondwanan region. On the basis of the collection, two new species of Pterotheca—P. yongshunensis and P. xiushanensis—were identified and are described herein. The morphologic analysis suggests that close relatives of these new species may be Pterotheca species from the Telychian of Scotland. The new species show continuous variations of marginal apex to submarginal apex, implying that one of the Pterotheca species may be ancestral to the Devonian Aspidotheca Spriesterbach, 1919. The Pterotheca species from South China possibly lived a slowly crawling life on a soft substrate, feeding on algae and/or detritus, and were adapted to a shallow-water setting with substantial terrigenous input. Given that all the known Silurian Pterotheca species occurred in siliciclastic settings, most of which represent sea-level fall and lowstand periods, we demonstrate that geographic isolation and enhanced ocean circulation during the early Silurian regression facilitated the speciation of Pterotheca globally, and the connection of a sea pathway during the Rhuddanian transgression after the end-Ordovician glaciation could have led to the primary dispersal of Silurian Pterotheca.

The rapid advancement of large language models (LLMs) has enabled their integration into a wide range of scientific disciplines. This article introduces a comprehensive benchmark dataset specifically designed for testing recent LLMs in the hydrology domain. Leveraging a collection of research articles and hydrology textbooks, we generated a wide array of hydrology-specific questions in various formats, including true/false, multiple-choice, open-ended, and fill-in-the-blank. These questions serve as a robust foundation for evaluating the performance of state-of-the-art LLMs, including GPT-4o-mini, Llama3:8B, and Llama3.1:70B, in addressing domain-specific queries. Our evaluation framework employs accuracy metrics for objective question types and cosine similarity measures for subjective responses, ensuring a thorough assessment of the models’ proficiency in understanding and responding to hydrological content. The results underscore both the capabilities and limitations of artificial intelligence (AI)-driven tools within this specialized field, providing valuable insights for future research and the development of educational resources. By introducing HydroLLM-Benchmark, this study contributes a vital resource to the growing body of work on domain-specific AI applications, demonstrating the potential of LLMs to support complex, field-specific tasks in hydrology.

Specimens of Tulaneia amabilia Runnegar and Horodyski n. gen n. sp. (previously Ernietta plateauensis Pflug) discovered by RJH in 1991 at a site in the Montgomery Mountains near Johnnie, Nevada, are described for the first time. All of the material from the original locality was from float, but its stratigraphic position within the lowest siliciclastic to dolostone interval of the lower member of the Wood Canyon Formation (LMWCF) was confirmed by subsequent discoveries. Because the upper part of the LMWCF contains Treptichnus pedum (Seilacher), the Ediacaran–Cambrian boundary has long been drawn at its first appearance. However, in the Esmeralda Member of the Deep Spring Formation in the White-Inyo Mountains, California, and at Mount Dunfee, Nevada, another Cambrian ichnofossil, ‘Plagiogmus’, which is now Psammichnites gigas arcuatus (Roedel), is found just beneath the nadir of the basal Cambrian isotope excursion (BACE). Because the nadir of the BACE excursion is older than ca. 539 Ma in Mexico, the oldest occurrences of Treptichnus pedum in the LMWCF are latest—not earliest—Fortunian in age, and there is no need to reduce the age of the eon boundary from ca. 539 to ca. 533 Ma. Tulaneia resembles Ernietta and other erniettomorphs in being composed of tubular modules with planar common surfaces, but its overall shape was tabular and unidirectional rather than sack or frond shaped. We also illustrate and briefly describe other trace and body fossils from the LMWCF and re-illustrate previously published specimens of Psammichnites gigas arcuatus in order to document its earliest occurrence in the Great Basin.

UUID: http://zoobank.org/117efe63-c3b8-4c42-8a27-83af05630f48