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Past aridity and dust drove biodiversity crises and altered pollination in the ancient gymnosperm Ephedra (Gnetales)
No full textThe long-term effects of present-day climate change on pollination are unquantified. However, distinguishing climaticdrivers of ancient changes in pollination could provide valuable insights into biotic responses to near-future climate states.Herein, we show that pollination in a group of gymnosperm shrubs (Ephedra L., Gnetales) was irrevocably altered by theCenozoic expansion of drylands on two different continents. In Asia, increased continentality during the mid-Eocenedrove aridification and strong, dust-carrying storms that promoted a shift to prevailing wind pollination in the core cladeof Ephedra. Surface uplift in the North American interior together with global cooling caused the expansion of aeoliandeposition and placed similar evolutionary pressures on ephedras there, beginning in the latest Eocene and continuingacross the Eocene–Oligocene transition (EOT). These climatic changes fundamentally altered the abundance and evo-lution of this ancient plant lineage on both continents and determined pollination mechanisms in the core clade of Ephedratoday. Based on fossil evidence, this review demonstrates how climate change may have major and permanent impacts onplant–pollinator networks, as well as demonstrates possible evolutionary consequences of near-future climate scenariosfor which we have no modern analogue
A first Triassic insect from Antarctica (Eisenhower Range, northern Victoria Land)
No full textWe report here an isolated insect forewing from Triassic deposits of the Eisenhower Range, northern Victoria Land, Antarctica. Based on the reduced venation (e.g. well-developed pterostigma, Rs dichotomously branched, Rs and M vein with five branches each), we tentatively identify the specimen as belonging to Permochoristidae (Mecoptera). However, due to incomplete preservation of the forewing, we prefer a determination under open nomenclature until more material of this taxon is available. The new specimen represents the first insect described from the Triassic of Antarctica and the first fossil record of Mecoptera in the continent, supporting the worldwide distribution and a greater diversity of the family during Triassic times
An opalised mid-Cretaceous flora from the Griman Creek Formation at lightning ridge, eastern Australia
No full textA rich Albian–Cenomanian opalised plant fossil assemblage is described from the Griman Creek Formation at Lightning Ridge in the Surat Basin, northern New South Wales, Australia. The fossils are preserved predominantly as opal casts that retain few anatomical or micromorphological epidermal details. For this reason, most fossils are difficult to assign with higher taxonomic resolution than to plant families. Nevertheless, the assemblage appears to be dominated by scale-leafed cupressacean foliage and cones, with lesser proportions of araucariacean, podocarp and possibly cheirolepidacean conifers that likely constituted the middle and upper storeys of the palaeovegetation. Understorey ferns and sphenopsids are sparse. Angiosperms are notably absent but unusual pyramidal seeds may indicate the presence of the Bennettitales-Erdtmannithecales-Gnetales group in the palaeoflora. The plant fossils are co-preserved with a broad range of terrestrial and aquatic vertebrate and invertebrate remains that collectively attest to a coastal plain setting fringing the Surat Basin embayment of the epeiric ‘Eromanga Sea’, which flooded the epicratonic Great Artesian Basin complex during the Early Cretaceous. Several plant groups are shared with broadly coeval fossil floras from eastern Australia and New Zealand reflecting a fairly typical mid-Cretaceous middle- to high-latitude austral flora, but the Lightning Ridge assemblage notably lacks delicate and broad-leafed taxa, possibly owing to preservational and sampling biases. We highlight opportunities for the study of opalised plant fossils from various other assemblages in eastern Australia and note that analysis of future collections of carefully extracted specimens from the Lightning Ridge deposits offer the potential to yield micromorphological details
Palynofloras across the Triassic–Jurassic boundary on Qinghai-Tibetan Plateau, Southwest China
No full textThe Triassic–Jurassic boundary (TJB) of the Qinghai-Tibetan Plateau is exposed at the Germig Section in southern Xizang (Tibet), Southwest China. This marine TJB succession is well-constrained by ammonite and bivalve stratigraphy, providing a robust chronological framework. Based on the palynofloral assemblages from the Germig Section, we recognized two assemblages, one Rhaetian and one Hettangian. The Rhaetian assemblage is dominated by bisaccate pollen, which shifts across the TJB to a Hettangian Classopollis dominated assemblage, reflecting a change from a seed-fern/conifer-dominated flora to one dominated by cheirolepids. This palynofloral change has been recognized elsewhere, but appears to be diachronous across Gondwana. This is highlighted by our study, which demonstrates that the characteristic post-extinction cheirolepid forests appeared earlier at lower latitudes.This work was supported by National NaturalSciences Foundation of China (grant number 42293280); the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (20231102); the Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0706); the Swedish Research Council (VR)(grant numbers 2019-04524, 2023-03330, for S.S. and 2019-4061 for V.V.); Formas (Swedish Research Councilfor Sustainable Development; 2023-00984 for S.S.); andKnut and Alice Wallenberg Foundation (grant number KAW 2020.0145 for V.V.). We thank Anna FijałkowskaMader and one anonymous reviewer for their detailed evaluation and constructive suggestions on this manuscript.</p
A 75,000-y-old Scandinavian Arctic cave deposit reveals past faunal diversity and paleoenvironment
No full textDuring the last glacial period (~118 to 11.7 ka), the Arctic has been characterized bya major redistribution of flora and fauna as a consequence of extreme climatic fluctua-tions, with associated glacial advances and retreats, sea-level changes, and shifting seaice extent. In the high- latitude regions of Northern Europe that are currently subject torapid climate warming, we lack a comprehensive understanding of faunal biodiversityin the last glacial period due to the extreme rarity of preserved organic remains. Here,we present a stratified sediment deposit with a diverse faunal composition preservedin a bone- bearing layer in Arne Qvamgrotta, part of the Storsteinhola cave system(68.10° N 16.38° E) in Northern Norway. Chronological analyses of sediments andbones including radiocarbon, optically stimulated luminescence, uranium–thorium, andphylogenetic dating place the faunal assemblage in Marine Isotope Stage 5a (MIS 5a,Odderade interstadial, ~85 to 71 ka). Combining comparative osteology and bulk-bonemetabarcoding, we identify 46 taxa, including mammals, birds, and fish, with sev-eral species not previously found in Fennoscandia. The fauna implies a nonanalogouscold- adapted coastal community, with close proximity to sea ice and nearby freshwaterbodies. Mitogenome analyses of a subset of taxa identify extinct lineages which attestto a lack of habitat tracking and the absence of a local refugium during the subsequentfully glaciated periods. This faunal record demonstrates long-term faunal dynamics andcoastal environmental conditions during MIS 5a in the European Arctic
Osteometry of Duck Species in Northwestern Europe—A Reassessment of Woelfle's (1967) Dataset
No full textThis study revisits and expands upon Elisabeth Woelfle's (1967) foundational analysis of bone morphology and osteometry,which has long been a key reference for zooarcheological identification of duck species in northwestern Europe. By examiningWoelfle's unpublished measuring protocols and incorporating 523 newly measured specimens, we evaluate the reliability of traditionalskeletal measurements. Our results highlight significant inconsistencies in inter-andintra-observerreproducibility ofseveral commonly used metrics. We identify nine problematic measurements and propose revised definitions to improve standardizationand recommend abandoning poorly defined metrics. This revision aims to refine osteometric practices for ducks andpotentially other avian taxa, to ensure greater accuracy in zooarcheological identifications. All measurement data, including digitizedversions of Woelfle's original data, are made publicly available to support further morphological and comparative studies
Exploring the unusual occurrence, chemistry, and structural topology of åsgruvanite-(Ce), Ce16Ca5Al(SiO4)6(AsO3)8(CO3)2Cl3(ClF3)(OH)2 , a new rare earth element (REE) mineral from Västmanland, Sweden.
No full textÅsgruvanite-(Ce), ideally Ce16Ca5Al(SiO4)6(AsO3)8(CO3)2Cl3(ClF3)(OH)2, is a new mineral species (IMA–CNMNC 2025-004), from the Åsgruvan Fe-skarn deposit, Norberg, Västmanland, Sweden, which is directly related to the Bastnäs-type of REE mineralisations in the Palaeoproterozoic Bergslagen ore province. Åsgruvanite-(Ce) occurs as anhedral, occasionally elongated grains up to 400 µm. It is greyish green to nearly colourless, with a white streak and a vitreous to greasy lustre. Cleavage is distinct on {001} and less so on {100}; the mineral is brittle, and its fracture is uneven. The calculated density is 4.79(1) g·cm⁻³. Åsgruvanite-(Ce) is optically uniaxial (+), with a refractive index above 1.8; the calculated average is 1.88 (Gladstone–Dale approach). Åsgruvanite-(Ce) crystallises in the trigonal system, space group P-3m1 (Z = 1), with the following unit-cell parameters: a = 10.5728(6) Å, c = 15.0899(11) Å. Åsgruvanite-(Ce) occurs in a magnetite–REE skarn, but its formation postdates the groundmass carbonate and skarn assemblage, and it is associated with late-stage calcite, dolomite, a dollaseite-like allanite-group mineral, gadolinite-(Y/Nd), and a fluorocarbonate related to bastnäsite-(Ce), with variable F contents. The structure was refined to R1 = 6.23% for 987 reflections. It is unique and consists of two alternating layers, A and B, along the c axis. Layer A (~8.4 Å) has the composition [(Ce12Ca3)AlSi6(C1.50S0.50)S2.00O30(OH)2]15+. Layer B (~6.7 Å) corresponds to the composition [(Ce4Ca2)As3+8O24Cl4F3]15–. These layers form tunnel-like features parallel to [100], which are partially occupied by Cl atoms. Spectroscopic data (infrared and micro-Raman) support the structural model
