Mecochirid lobsters (Glypheidea, Mecochiridae) are iconic decapod crustaceans from the Jurassic and Cretaceous. The composition of the family in terms of included genera strongly fluctuated during the twentieth century because of the lack of study of the type specimens, which are herein illustrated. On the basis of the type material of different species housed in German, French, British, and Romanian museums and universities, Eumorphia von Meyer, 1847 (type species Carcinium sociale von Meyer, 1841) is re-established as a valid mecochirid genus. Six species are considered, including the new species Eumorphia fabianmuelleri (Callovian, Germany), and the synonymization of Romaniacheiros Franţescu et al., 2018 with Eumorphia is proposed. The composition of the revised family Mecochiridae is discussed.

UUID: http://zoobank.org/6a518009-c139-4ff6-8669-c9994a698cc5

The cyclopoid family Bomolochidae Claus, 1875 is one of the most common groups of parasitic copepods infesting fishes worldwide. During a survey of marine fishes from northeast Brazil, a new species of Naricolax Ho, Do & Kasahara, 1983 was found in the nasal cavities of the littlescale threadfin Polydactylus oligodon (Günther, 1860) (Polynemidae) in the Maranhão Gulf, Brazil. Naricolax zafirae sp. nov. can be distinguished from all congeners because it has a pair of acutely pointed tines in the rostral area and an elongated last endopodal segment of leg 4, features that have never been reported in the genus. In addition, the new species differs from the closely related congeners by having a T-shaped rostral area, an outer spine on the second endopodal segment of leg 3 shorter than the segment, and by the apical seta on the last endopodal segment of leg 4 shorter than the rami. The present study provides the first report of a bomolochid parasitizing a fish of the family Polynemidae Rafinesque, 1815 as well as the first report of the genus Naricolax in the Atlantic Ocean. A dichotomous key for species of Naricolax is provided.

Documenting patterns of evolution and stasis has been a major focus of paleobiology. However, despite substantial knowledge gleaned on this topic, many questions related to the underlying environmental processes that determine the dynamics of evolution and stasis remain unresolved. Therefore, this study focuses on examining these evolutionary patterns framed within an environmental context. Specifically, we test Sheldon’s “Plus ça change” model, which predicts that morphological change is associated with more stable environments, such as in tropical latitudes or greenhouse climates, whereas stasis is linked to less stable environments, like those found in temperate latitudes or during icehouse climates. We examine the role that broadscale climatic variation exerts on evolutionary dynamics by documenting morphological change among nuculid bivalves in shallow-shelf settings from three different climate regimes: (1) the stable Late Cretaceous greenhouse climate; (2) the moderately stable Neogene transitional climate; and (3) the less stable Quaternary icehouse climate. Morphological changes over time were assessed using both bivalve size and outline shape. Comparison among changes in size and outline-shape patterns for Late Cretaceous and Neogene–Quaternary Nucula indicates that morphological change over time and stasis, respectively, dominated these different time intervals. In all cases, morphological change over time coincided with the more stable and less climatically variable greenhouse conditions, whereas stasis was associated with the more variable regimes characteristic of icehouse climates. These data provide strong support for the need to consider broad environmental factors—in this case climate—when assessing evolutionary modes. Furthermore, they point to the relevance of the Plus ça change model to explain patterns of evolution and stasis.

This paper treats new data about small mammals from the Chongphadae Cave Site, Democratic People’s Republic of Korea. Seven samples from Layers 8–10 and 12–15 included 161 tooth fossils of small mammals. The composition of small mammal assemblage is 3 orders, 5 families, and 11 species, which are 1 insectivore taxon, 1 lagomorph taxon, and 9 rodent taxa. The community development is distinguished into five stages (62.122–19.630 ka), and stage I is characterized by the dominance of xerophilous elements, including Myospalax epsilanus, Microtus brandti, and Cricetulus barabensis. Alternating between mesophilous and xerophilous elements, the last stage (stage IV) of community development is characterized by the existence of only mesophilous elements, such as Ochotona alpina and Erinaceus sp. The dynamics of small mammal communities of the Chongphadae Cave Site demonstrate that alternation between mesophilous and xerophilous elements during the Late Pleistocene contributed to the formation of the modern mosaic landscape consisting of forests, grasslands, and riverside.

The mixture of icebergs and sea ice in tidewater glacier fjords, known as ice mélange, is postulated to impact iceberg calving directly through physical buttressing and indirectly through freshwater fluxes altering fjord circulation. In this contribution, we assess the textural characteristics of ice mélange in summer and winter at the terminus of Helheim Glacier, Greenland, using high resolution (1-3 m) X-band Synthetic Aperture Radar (SAR) imagery from the ICEYE small satellite constellation. The Grey Level Co-occurrence Matrix (GLCM) and statistical variations in pixel intensity downfjord reveal structural zoning within the mélange matrix in both summer and winter. The boundary between these zones represents the transition between ice concentrations, demonstrating structural weaknesses in the mélange that may persist throughout the year. Furthermore, we compare two iceberg segmentation methods, texture-based vs the Segment Anything Model (SAM). Both techniques detect large (> 0. 1 km2) icebergs in summer when pixel variations are larger, but SAM has high iceberg detection accuracy in both seasons. The detected icebergs stabilise near concentration boundaries in the mélange, suggesting they act as the nucleus of mélange zones and control matrix stability. Our study demonstrates the potential for using high-resolution ICEYE SAR imagery for studying dynamic processes in glaciology and beyond.

This contribution identifies biogenic structures created by modern birds foraging in marginal aquatic settings and provides descriptions to facilitate their identification in the rock record. Biogenic structures related to foraging can be separated into those created by bills, such as peck marks, probe marks, gape marks, dabble marks, sweep marks, and bill-stir marks. Biogenic structures created by feet include stir tracks and paddle pits. Peck marks are created during visual foraging and result in shallow, solitary or paired, random or clustered, circular to subcircular pits and grooves. Probe marks are created during tactile foraging but are similar to peck marks, differing solely in their greater depth of penetration. Gape marks are formed when birds open their bill in the sediment resulting in elongated grooves. Dabble marks are larger ovoid divots emplaced by broad-billed waterbirds in subaqueous settings. Bill stirring occurs when a bird swishes its bill in a narrow trend on the sediment surface. Sweep marks are arcuate grooves emplaced in the sediment when long-billed birds forage by sweeping their bill side-to-side across the sediment–water interface.

Birds shuffling their feet in soft sediment is termed ‘foot-stirring’ and results in overprinted, side-by-side trackways. Foot-paddling dewaters the sediment and produces various pit morphologies with massive fill. Trackways emplaced during foraging are commonly characterized by variable stride length, stutter steps, and sudden changes in direction. ‘Trample grounds’ are produced by gregarious foraging flocks of birds. It is anticipated that illustrating and describing the structures produced by these behaviors will facilitate recognition of these commonly overlooked traces.

The Ovatoryctocara granulata Chernysheva, 1962 assemblage is a diverse fossil fauna that is important for global biostratigraphic correlation within Cambrian Series 2, Stage 4. The assemblage includes more than 60 invertebrate species in North Greenland from Freuchen Land to western Peary Land, but systematic documentation of all the fossils from the assemblage remains to be done. Here we expand on previous work by describing new mollusks and the problematic Stenothecoides from this assemblage in North Greenland, mainly from Freuchen Land. The identified taxa include Stenothecoides sp., Capitoconus borealis, Dorispira tippik Peel and Kouchinsky, 2022, Dorispira sp., Ressericonella pipalukae Oh and Peel, 2024, Ressericonella? sp., Mellopegma georginense Runnegar and Jell, 1976, Mellopegma simesi (MacKinnon, 1985), Yochelcionella gracilis Atkins and Peel, 2004, Eotebenna arctica Peel, 1989, Pelagiella sp., and three helcionelloid species in open nomenclature. These mollusks and stenothecoids facilitate faunal comparisons of North Greenland with Stage 4 to Miaolingian strata from other paleocontinents such as Siberia, Gondwana (Australia), and peri-Gondwana (North China), as well as within Laurentia.

Assessing glacier surface mass balance (SMB) is essential for evaluating glacier response to climate change. However, traditional in situ measurement methods are labour intensive and often lack the temporal and spatial resolutions required to fully constrain SMB models. Here, we explore the potential of the Global Navigation Satellite System Interferometric Reflectometry (GNSS-IR) technique which exploits reflected satellite signals to track surface height changes for continuous SMB estimation. Using data from 13 GNSS stations operating between 2019 and 2021 on Glacier d’Argentière (French Alps), we compare GNSS-IR-derived SMB with estimates from snow pits, wooden stakes, continuous ice-melt measurements using a SmartStake device, and a degree-day model. We demonstrate that the GNSS-IR technique can reliably estimate SMB values that closely match independent in situ measurements, while also offering the advantages of spatial integration and long-term time series that capture both snowfall events and snow/ice melt. We show that glacier surface roughness and antenna height, when the glacier is snow-free, strongly influence uncertainties, which can be reduced to as little as 2 cm d−1 using a smoothing filter. Finally, we demonstrate that the GNSS-IR technique can further constrain the degree-day factor, particularly its temporal evolution throughout the ablation season.

Garnet and biotite are common minerals in and adjacent to metamorphosed massive sulphide deposits, but their trace element compositions are rarely used to explore for such ores. Both minerals are present in hydrothermal alteration zones metamorphosed to the amphibolite facies spatially related to semi-conformable massive sulphide horizons in the Paleoproterozoic Stollberg Zn-Pb-Ag-(Cu-Au) plus magnetite ore field, Bergslagen district, Sweden. The major-trace element chemistry of garnet in metamorphosed altered rocks, mafic dykes and sulphide mineralisation shows that garnet in garnet-biotite alteration (and high-grade sulphides) is Fe-rich (almandine ratio > 0.5) whereas garnet in skarn and garnet-pyroxene alteration contains significantly higher amounts of Ca and Mn and elevated concentrations of Co, Cr, Ga, Ge, Sc, Ti, V, Y, Zn and the heavy rare earth elements (HREEs). Chondrite-normalized REE patterns of garnet in all rock types are depleted in light REEs and enriched in heavy REEs. Garnet in sulphide-bearing altered rocks, including garnet-biotite and garnet-pyroxene alteration, shows a strong positive Eu anomaly and the highest concentrations of Ga, Ge, Mn, Pb and Zn. Rocks more distal to sulphide mineralisation typically contain garnet that exhibits no or negative Eu anomalies and lower mean concentrations of these elements and higher concentrations of Ti. Biotite shows variable Fe/(Fe+Mg) ratios with most centred around 0.5 and enrichments in Ga, Mn, Sn, Pb and Zn in and adjacent to sulphides. This suggests that garnet and biotite can be used as a vectoring tool to ore in the Stollberg ore field and potentially for metamorphosed massive sulphides elsewhere.