Swedish Museum of Natural History
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Alternative and legacy flame retardants in marine mammals from three northern ocean regions
No full textFlame retardants are globally distributed contaminants that have been linked to negative health effects in humans and wildlife. As top predators, marine mammals bioaccumulate flame retardants and other contaminants in their tissues which is one of many human-imposed factors threatening population health. While some flame retardants, such as the polybrominated diphenyl ethers (PBDE), have been banned because of known toxicity and environmental persistence, limited data exist on the presence and distribution of current-use alternative flame retardants in marine mammals from many industrialized and remote regions of the world. Therefore, this study measured 44 legacy and alternative flame retardants in nine marine mammal species from three ocean regions: the Northwest Atlantic, the Arctic, and the Baltic allowing for regional, species, age, body condition, temporal, and tissue comparisons to help understand global patterns. PBDE concentrations were 100–1000 times higher than the alternative brominated flame retardants (altBFRs) and Dechloranes. 2,2′,4,5,5′-pentabromobiphenyl (BB-101) and hexabromobenzene (HBBZ) were the predominant altBFRs, while Dechlorane-602 was the predominant Dechlorane. This manuscript also reports only the second detection of hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO) in marine mammals. The NW Atlantic had the highest PBDE concentrations followed by the Baltic and Arctic which reflects greater historical use of PBDEs in North America compared to Europe and greater industrialization of North America and Baltic countries compared to the Arctic. Regional patterns for other compounds were more complicated, and there were significant interactions among species, regions, body condition and age class. Lipid-normalized PBDE concentrations in harbor seal liver and blubber were similar, but HBBZ and many Dechloranes had higher concentrations in liver, indicating factors other than lipid dynamics affect the distribution of these compounds. The health implications of contamination by this mixture of compounds are of concern and require further research
Graphic and statistical overview of temporal trends and spatial variations within the Swedish National Monitoring Programme for Contaminants in Freshwater Biota (until 2021 year’s data)
No full textGenome sequencing of 2000 canids by the Dog10K consortium advances the understanding of demography, genome function and architecture
No full textBackground The international Dog10K project aims to sequence and analyze several thousand canine genomes. Incorporating 20 × data from 1987 individuals, including 1611 dogs (321 breeds), 309 village dogs, 63 wolves, and four coyotes, we identify genomic variation across the canid family, setting the stage for detailed studies of domestication, behavior, morphology, disease susceptibility, and genome architecture and function. Results We report the analysis of > 48 M single-nucleotide, indel, and structural variants spanning the autosomes, X chromosome, and mitochondria. We discover more than 75% of variation for 239 sampled breeds. Allele sharing analysis indicates that 94.9% of breeds form monophyletic clusters and 25 major clades. German Shepherd Dogs and related breeds show the highest allele sharing with independent breeds from multiple clades. On average, each breed dog differs from the UU_Cfam_GSD_1.0 reference at 26,960 deletions and 14,034 insertions greater than 50 bp, with wolves having 14% more variants. Discovered variants include retrogene insertions from 926 parent genes. To aid functional prioritization, single-nucleotide variants were annotated with SnpEff and Zoonomia phyloP constraint scores. Constrained positions were negatively correlated with allele frequency. Finally, the utility of the Dog10K data as an imputation reference panel is assessed, generating high-confidence calls across varied genotyping platform densities including for breeds not included in the Dog10K collection. Conclusions We have developed a dense dataset of 1987 sequenced canids that reveals patterns of allele sharing, identifies likely functional variants, informs breed structure, and enables accurate imputation. Dog10K data are publicly available
Komlopteris: A persistent lineage of post-Triassic corystosperms in Gondwana
No full textKomlopteris is a genus that includes the youngest representative of the so-called ‘seed ferns’, an informal group of gymnosperms that were prevalent during the Mesozoic but largely went extinct at the end of the Cretaceous. New fossil material, morphological data, and an extensive literature review allowed us to clarify the systematics of Gondwanan post-Triassic leaves of the Komlopteris lineage that were formerly assigned to diverse genera. Trends in diversity and distribution were identified. Ten species of Komlopteris were recognized in Jurassic to Eocene strata across Gondwana. Earliest records of the genus derive from South America soon after the end-Triassic extinction event. The genus reached its peak diversity and range in the Late Jurassic and Early Cretaceous and declined markedly after the Aptian. Its youngest representation is in mid-Cretaceous to Eocene deposits of southeastern Gondwana. Although never dominant, Komlopteris represents an important subsidiary component of austral Jurassic–Paleogene plant fossil assemblages. Striking morphological similarities to Dicroidium and Kurtziana, and co-occurrence with low concentrations of Alisporites/Falcisporites-type pollen, suggest that Komlopteris was a gymnosperm belonging to Umkomasiales (=Corystospermales) that survived the end-Triassic and end-Cretaceous biotic crises in climatically buffered humid habitats of high southern latitudes. Arthropod induced leaf damage was rare on Komlopteris foliage and recognized only in two Late Jurassic–Early Cretaceous species.This work was supported by the University of Adelaide, Gostralia! [PhD scholarship to MS], the Australasian Systematic Botany Society [Hansjörg Eichler Scientific Research Fund to MS], and the Swedish Research Council (VR grant numbers 2018-04527 and 2022-03920 to SM).</p
The Koonwarra Fossil Fish Beds Konservat-Lagerstätte: an Update
No full textThe Koonwarra Fossil Fish Beds located in South Gippsland, Victoria, Australia is renowned for the quality and quantity of the Early Cretaceous fossil plants, arthropods and fish recovered from this ancient lake deposit.Funding is acknowledged from the Knut & Alice Wallenbergs stiftelse KAW 2020.0145 (V. Vajda), Swedish Research Council VR grants 2019-4061 (V. Vajda), and a Swedish Strategic Research Fund fellowship to O.S.</p
Dormice (Rodentia, Gliridae) from the Middle Miocene of Hambach 6C, Northwest Germany
No full textGlirid dental material is described from the Middle Miocene channel fill of the Hambach open-cast lignite mine in northwestern Germany. The fauna Hambach 6C shows a high diversity with seven species in six genera: Glirudinus undosus, Muscardinus thaleri, Muscardinus sansaniensis, Miodyromys aegercii, Paraglirulus werenfelsi, Microdyromys koenigswaldi, and Paraglis astaracensis, which are characteristic taxa in Middle Miocene European localities. Regarding the faunal composition and high diversity, the Hambach 6C assemblage is closest to that of the MN 5 locality Schönenberg in southern Germany, but also shares many taxa with late Middle Miocene faunas. The species richness of glirids, combined with other vertebrate remains in Hambach 6C indicates a warm, humid forested environment during the Mid-Miocene Climate Optimum (MCO).We are very thankful to the mining company RWE POWER AG (Cologne) for the continuous support during fieldwork in the Hambach mine. ZY.L. received support from the National Natural Science Foundation of China (NSFC 42172010) and Chinese Government Scholarship (CSC 202106970018). T.M. was funded by the Deutsche Forschungsgemeinschaft (DFG) Special Research Project SFB 350.</p
Fibrous or Prismatic? A Comparison of the Lamello-Fibrillar Nacre in Early Cambrian and Modern Lophotrochozoans
No full textThe Precambrian–Cambrian interval saw the first appearance of disparate modern metazoan phyla equipped with a wide array of mineralized exo- and endo-skeletons. However, the current knowledge of this remarkable metazoan skeletonization bio-event and its environmental interactions is limited because uncertainties have persisted in determining the mineralogy, microstructure, and hierarchical complexity of these earliest animal skeletons. This study characterizes in detail a previously poorly understood fibrous microstructure—the lamello-fibrillar (LF) nacre—in early Cambrian mollusk and hyolith shells and compares it with shell microstructures in modern counterparts (coleoid cuttlebones and serpulid tubes). This comparative study highlights key differences in the LF nacre amongst different lophotrochozoan groups in terms of mineralogical compositions and architectural organization of crystals. The results demonstrate that the LF nacre is a microstructural motif confined to the Mollusca. This study demonstrates that similar fibrous microstructure in Cambrian mollusks and hyoliths actually represent a primitive type of prismatic microstructure constituted of calcitic prisms. Revision of these fibrous microstructures in Cambrian fossils demonstrates that calcitic shells are prevalent in the so-called aragonite sea of the earliest Cambrian. This has important implications for understanding the relationship between seawater chemistry and skeletal mineralogy at the time when skeletons were first acquired by early lophotrochozoan biomineralizers
