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A new species of Anthocotyle (Polyopisthocotyla: Discocotylidae) from the gills of the European hake Merluccius merluccius (Teleostei, Merlucciidae) with a revision of the composition of the genus
No full textThis study revisits the taxonomy of Anthocotyle merluccii, originally described from the European hake Merluccius merluccius in the northeast Atlantic, addressing discrepancies in clamp morphology across populations. The original description from Belgium noted near-equal anterior clamp sizes, contrasting with populations from Plymouth (Atlantic) and the Mediterranean, which show marked size differences, questioning their conspecificity. We describe A. radkeaminorum n. sp. from M. merluccius in the western Mediterranean (off Algeria), distinguished from A. merluccii (Belgium) by differing anterior clamp size, genital atrium spine number, and overall anterior clamp dimensions. Populations from Plymouth, previously attributed to A. merluccii, are herein assigned to A. aff. merluccii based on differences in morphometrical traits pending further investigations. Additionally, A. radkeaminorum n. sp. differs from A. americanus in body and clamp size, atrial spine count, and hosts. Based on analysis of morphological and molecular data, we refute the synonymy of A. merluccii and A. americanus, and we reinstate the latter as a valid species. The distinction between A. merluccii and A. americanus was further supported by divergence in cox1 gene sequences analyzed from GenBank (10–11%). Finally, inconsistencies in terminal lappet hook morphology are discussed, cautioning against its use in species delineation. This work highlights the need for continued research to resolve species relationships within this genus.Systematics and integrative taxonomy of Monogenea parasitizing fishes of Swede
Introducing the akrochordite mineral group, with the new mineral vargite from the Långban Mn-Fe deposit, Filipstad, Värmland, Sweden
No full textVargite, ideally MnCu2Mn2(OH)4(H2O)4(AsO4)2 ? named after the Swedish miner Erik Gustaf Varg (1886?1970), who collected the type specimen ? was found in the Långban Fe-Mn deposit. It occurs in open cavities in a brecciated and later hydrothermally leached carbonate groundmass, in association with hausmannite, calcite, rhodochrosite, baryte, a serpentine-group mineral, and galena. Additional minor phases are hedyphane, phlogopite and yarrowite. Paragenetically, it is a late-stage mineral, formed as a result of the interaction between an As-rich hydrothermal fluid and Mn-oxide(s) and Cu-sulphide, under low P- and T-conditions. Vargite forms bright green, semi-spherical aggregates up to 0.5 mm across, consisting of numerous thin, lath-shaped crystals, elongated along [100] and with a maximum length of 200 µm. Mohs hardness is ≈ 3 and Dcalc?=?3.49(1)?g·cm?3. The empirical chemical formula obtained from electron probe micro-analyses analyses and based on 16 anions is (Cu1.77Mg0.33)Σ2.10(Mn2.94Ca0.04Pb0.01)Σ2.99(As1.95Si0.02)Σ1.97O8(OH)4.03·3.98H2O. The crystal structures of vargite and the isotypic mineral akrochordite [MnMn2Mn2(OH)4(H2O)4(AsO4)2] have been refined in the space group P21/c from single-crystal X-ray diffraction data to R1?=?3.07% and 2.46%, respectively, giving the following sets of unit-cell parameters: a?=?5.6251(14), 5.6832(11) Å, b?=?17.452(5), 17.631(5) Å, c?=?6.905(2), 6.8417(19) Å, ??=?100.21(5)°, 99.51(4)°, and V?=?667.2(3), 676.1(3) Å3, with Z?=?2. A Raman spectrum of vargite, with major bands at 3510, 1610, 850, 780, 476, 428, 389, and 308?cm?1, strongly resembles that of isotypic guanacoite, [MgCu2Mg2(OH)4(H2O)4(AsO4)2]. Vargite, akrochordite, and guanacoite constitute the newly established akrochordite group
Mat-forming lichens support contrasting micro-arthropod density
No full textMat-forming lichens are important components of tundra and alpine vegetation, and affect soil microclimatic conditions, which in turn may influence micro-arthropod communities. Here, we compare the density of Collembola and Oribatida within lichen mats and their abundance in the underlying soil across four different mat-forming lichens at Finse, southern Norway. The lichen mats consisted of Alectoria ochroleuca, Cetraria islandica, Cladonia rangiferina/stygia, or Flavocetraria nivalis. We hypothesized that lichens with high water holding capacity (WHC) create a cool and stable microclimate with few freeze-thaw cycles which sustains a high micro-arthropod density in lichen and abundance in soil. We further test how lichen monocultures affect soil element availability. The abundance of micro-arthropods differed among lichen species. Cladonia rangiferina/stygia supported the highest Collembola density, and lichens with high WHC supported higher densities, and relatively more Collembola in the lichen than the soil underneath. Oribatida were less responsive than Collembola but increased in lichen mats relative to soil with increasing WHC. Lichen mat density, soil temperature and freeze-thaw cycles did not correlate to micro-arthropod abundance. Element availability was higher in bare soil compared to soil covered with lichens driven by differences in temperature and freeze-thaw cycles, which possibly affect microbial activity. Lichen cover in boreal and tundra ecosystems is expected to decrease due to environmental change, which may significantly impact micro-arthropod communities in lichen-dominated vegetation
Seedless Land Plants: Fossil Record, Evolution and Diversification
No full textFerns, lycophytes, mosses, liverworts and hornworts (the last three collectively termed bryophytes), along with various extinct lineages, represent a paraphyletic grade of spore-producing plants that appeared early in the fossil record of the terrestrialization of life. About 32,000 extant spore-producing plant species are known and several thousand extinct forms have been documented from the fossil record. Free-sporing plants played major roles in middle and late Paleozoic terrestrial ecosystems, and their fossil remains contributed to a large proportion of the world’s coal and gaseous hydrocarbon resources. Their relative importance, compared to seed plants has diminished since the Paleozoic except for intervals of resurgence after mass extinction events, and a phase of renewed diversification with the appearance of angiosperm-dominated closed forests in the Late Cretaceous and Cenozoic. Their complex and dynamic evolutionary history poses challenges for phylogenetic reconstruction, but also illustrates how this group evolved multiple strategies for arborescent growth, construction of leaves, heterospory, and the development of new lineages through genome duplications. Their long-term evolutionary success highlights their great adaptability in a changing world
The Chinese plant fossil collections of Thore Gustaf Halle in the Swedish Museum of Natural History
No full text托勒·古斯塔夫·古斯塔夫松·赫勒（ThoreGustaf Gustafsson Halle，1884 年9 月25 日－1964 年5 月12 日；也经常被译为哈勒）是20 世纪上半叶活跃在国际古植物学界的著名瑞典古植物学家。在乌普萨拉大学完成本科学业后，他作为地质学家和古生物学家参加了 1907 － 1909 年斯科茨贝里（Carl Skottsberg）率领的考察队，前往福克兰群岛（也即马尔维纳斯群岛）、智利、阿根廷和巴西进行考察。1907 年10 月至1908 年2 月，赫勒在福克兰群岛花费了近四个月的时间，绘制了那里的地质和地貌图，收集并记录了泥盆纪、二叠纪和第四纪的化石植物。1911 年，在乌普萨拉大学赫格布姆（Arvid-Gustaf Högbom）教授的指导下，他据此进行研究完成了博士论文，获得博士学位。Thore Gustaf Gustafsson Halle (September 25, 1884 – May 12, 1964; also often translated as Halle) was a renowned Swedish paleobotanist active in the international paleobotanical community during the first half of the 20th century. After completing his undergraduate studies at Uppsala University, he participated as a geologist and paleontologist in the 1907–1909 expedition led by Carl Skottsberg, which explored the Falkland Islands (also known as the Malvinas Islands), Chile, Argentina, and Brazil. From October 1907 to February 1908, Halle spent nearly four months in the Falkland Islands, mapping its geology and topography, and collecting and recording Devonian, Permian, and Quaternary fossil plants. In 1911, under the guidance of Professor Arvid-Gustaf Högbom at Uppsala University, he completed his doctoral dissertation based on this research, earning his doctorate
Branched Setae or Attached Macroalgae: A Case Study of an Exceptionally Preserved Brachiopod from the Early Cambrian Chengjiang Lagerstätte
No full textThe remarkable conservation of soft tissues within Cambrian fossils has significantly enhanced our comprehension of the origins and evolutionary trajectories of animals, in addition to the progression of ecological intricacy. Here, we report an exceptionally preserved specimen of the lingulid brachiopod Xianshanella haikouensis from the lower Cambrian Chengjiang Lagerstätte, exhibiting branched fringes along the distal ends of its marginal setae. These structures may represent either branched setae or attached macroalgae. The diameter of the branched fringes is slightly larger than that of the marginal setae, and they exhibit third- or fourth-order bifurcations, forming a complex structure comparable in length to the shell. Both the branched fringes and marginal setae are preserved as iron oxides, as revealed by SEM and Micro-XRF analyses, a characteristic preservation mode in Chengjiang fossils. The results of Micro-CT scanning suggest that these branched fringes are preserved along almost the entire distal end of marginal setae. Comparable branched fringes are reminiscent of those found in annelids, and such structural analogs between annelid and brachiopod setae support the homology of brachiopod and annelid setae, representing a lophotrochozoan synapomorphy. An alternative explanation involving attached macroalgae is proposed, given that branched setae have never been documented in either extinct or extant brachiopod taxa. If these structures represent macroalgae, this association could represent a mimicry strategy to deceive predators, although comparable macroalgal fossils remain undocumented in the Chengjiang Lagerstätte. Our research highlights the potential for brachiopod setae to serve roles in sensory function or ecological interactions, offering a new perspective on early animal adaptation and community dynamics.This contribution was funded by research projects from the National Key Research and Development Program of China (2023YFF0803601), the National Natural Science Foundation of China (42302010, W2441016), the China Postdoctoral Science Foundation (2023M732836), the Postdoctoral Fellowship Program of CPSF (GZB20230590), Department of science and technology of Shaanxi Province (2022TD-11), and 111 Project (D17013). Research of L.E. Holmer is supported by the Swedish Research Council (VR2018-03390) and by a Zhongjian Yang Scholarship from the Department of Geology, Northwest University. Research of T.P. Topper is supported by the Swedish Research Council (VR2021-04295).</p
Results from Reindl et al . (2025) support rather than challenge the sequence hypothesis
No full textGraphicand statistical overview of temporal trends and spatial variations within the Swedish National MonitoringProgramme for Contaminants in Marine Biota (including data through 2024)
No full textAncient life in the Koonwarra Fossil Beds
No full textIn our recent work, published in the journal Review of Palaeobotany and Palynology (Vajda et al. 2025) we have been exploring one of the most extraordinary fossil sites in Australia, the Koonwarra Fossil Bed in Victoria. This site has long fascinated scientists because it captures, in remarkable detail, the life that thrived in a polar ecosystem during the Early Cretaceous. Thanks to the long-term research efforts of the scientists Tom Rich and Patricia Vickers-Rich and other colleagues including John Talent, Mary Dettmann, Peter Jell, Andrew Drinnan, amongst others, the astonishing diversity of life represented in the fossil assemblages have been revealed. The successions hide shoals of small fish, beetles and dragonflies, ginkgo forests, delicate early flowers (angiosperms). Feathers, preserved with microscopic details of their structure, remain among the most thrilling clues of ancient bird and dinosaur life in the Southern Hemisphere
