Swedish Museum of Natural History
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Constraining the exhumation history of the northwestern margin of Tibet with a comparison to the adjacent Pamir
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New rare and threatened species of Peponidium and Pyrostria (Rubiaceae, Vanguerieae) from the drylands of Madagascar
No full textFour new species of the tribe Vanguerieae (Rubiaceae) from southern, southwestern and western Madagascar are described and illustrated. Two species belong to the genus Pyrostria Comm. ex Juss.: P. costata Klack. & Razafim. with small leaves and distinctly ribbed pollen presenters and fruits, and P. macrocarpa Klack. & Razafim. characterized by its large, obconical, 5 – 6-lobed fruits. The other two species belong to the Malagasy subendemic genus Peponidium Ar.nes: P. leroyi Klack. & Razafim., characterized by hairy leaves with ciliate margins, sparsely pubescent flowers and ribbed pollen presenters, and P. sessile Klack. & Razafim., distinct by its cordate almost sessile leaves and double-tipped corolla lobes. Risk of extinction assessments for all four species are presented, as well as the respective distribution maps
Long-term dataset for contaminants in fish, mussels, and bird eggs from the Baltic Sea
No full textWidespread persistent contaminants are a global environmental problem. In the Baltic Sea, wildlife contamination was first noticed in the 1960s, prompting the Swedish Environmental Protection Agency to establish a comprehensive Swedish National Monitoring Programme for Contaminants in Marine Biota (MCoM) in 1978 run by the Swedish Museum of Natural History. Eight species have been analysed, four fish species (Atlantic herring, Atlantic cod, European perch, viviparous eelpout), one bivalve species (blue mussel), and egg from three bird species (common guillemot, common tern, Eurasian oystercatcher). Here, we present a dataset containing MCoM data from its start until 2021. It includes 36 sets of time-series, each analysed for more than 100 contaminants. The longest time-series is for common guillemot and starts in 1968. We describe the structure of MCoM including historic changes to the number of stations, sample treatment, analytical methods, instruments, and laboratories. The MCoM data is available at the Bolin Centre repository and on GitHub through our R package mcomDb. The latter will be updated yearly with new MCoM records
Eocene Shark Teeth From Peninsular Antarctica: Windows to Habitat Use and Paleoceanography
No full textEocene climate cooling, driven by the falling pCO2 and tectonic changes in the Southern Ocean, impacted marine ecosystems. Sharks in high‐latitude oceans, sensitive to these changes, offer insights into both environmental shifts and biological responses, yet few paleoecological studies exist. The Middle‐to‐Late Eocene units on Seymour Island, Antarctica, provide a rich, diverse fossil record, including sharks. We analyzed the oxygen isotope composition of phosphate from shark tooth bioapatite (δ18Op) and compared our results to co‐occurring bivalves and predictions from an isotope‐enabled global climate model to investigate habitat use and environmental conditions. Bulk δ18Op values (mean 22.0 ± 1.3‰) show no significant changes through the Eocene. Furthermore, the variation in bulk δ18Op values often exceeds that in simulated seasonal and regional values. Pelagic and benthic sharks exhibit similar δ18Op values across units but are offset relative to bivalve and modeled values. Some taxa suggest movements into warmer or more brackish waters (e.g., Striatolamia, Carcharias) or deeper, colder waters (e.g., Pristiophorus). Taxa like Raja and Squalus display no shift, tracking local conditions in Seymour Island. The lack of difference in δ18Op values between pelagic and benthic sharks in the Late Eocene could suggest a poorly stratified water column, inconsistent with a fully opened Drake Passage. Our findings demonstrate that shark tooth bioapatite tracks the preferred habitat conditions for individual taxa rather than recording environmental conditions where they are found. A lack of secular variation in δ18Op values says more about species ecology than the absence of regional or global environmental changes.The project analyses, GLC, and AA were supported by the National Science Foundation (NSF) Awards 1842049 and 1842059 to SLK and MH, respectively. Fieldwork was supported by the Swedish Research Council (VR) Grant 2009‐4447 and the Carl Tryggers Foundation (CTS) Grant 20:300 to TM. The study of the chondrichthyan remains was supported by the Austrian Science Fund (FWF) Grant P 26465 to JK. We would like to acknowledge high‐performance computing support from the Derecho system (https://doi.org/10.5065/qx9a‐pg09) provided by the NSF National Center for Atmospheric Research (NCAR), sponsored by the National Science Foundation.</p
Evolutionarily ancient deep‐water seep communities in the Eocene Tethys: examples from Buje (Croatia)
No full textWe report a newly discovered hydrocarbon seep deposit from the Eocene bathyal flysch, exposed in the town of Buje in Istria, Croatia. Molecular fossils of methane-oxidizing prokaryotes and abundant banded botryoidal cements indicate strong fluid flux at this site. We systematically describe the fauna of this and another seep deposit previously reported from Buje. The faunal assemblages are composed of eight species, these being an unidentified solemyid protobranch bivalve, the nuculid Nucula bowerbanki?, the nuculanid Nuculana? sp., the mytilid Brachidontes? amanoi sp. nov., the two thyasirids Channelaxinus dinaricus sp. nov. and Thyasira histriaensis sp. nov., the lucinid bivalve Amanocina bujensis sp. nov., and a possible provannid gastropod. The two assemblages are of low diversity (4 and 5 species, respectively), and are dominated by chemosymbiotic species whose occurrence is largely restricted to seeps. Despite their spatial and stratigraphic proximity, the two deposits share only a single species, Channelaxinus dinaricus, probably due to different fluid flux regimes at both seeps. The Buje seep assemblages are among the very few Late Cretaceous to Palaeogene chemosynthesis-based faunal assemblages from the Tethys Ocean (the others being Late Cretaceous vent assemblages from Cyprus). From an evolutionary perspective, the Buje seep communities consist of genera with Mesozoic origins but lack Cenozoic novelties such as bathymodiolin mussels and vesicomyid clams, which are known from coeval deposits from the Pacific and dominate vents and seeps today. Thus, the Buje seep fauna support previous assertions that the Eocene Tethyan seep faunas preserved an ancient aspect, whereas evolutionary novelties arose in the Pacific.This research was funded by NCN grant 2014/15/B/ST10/04886 to KH and AK, and by the Swedish Research Council (Vetenskapsrådet) through grant 2016-03920 to SK.</p
Checklists of the Ceraphronoidea, Cynipoidea, Evanioidea, Stephanoidea and Trigonalyoidea (Hymenoptera) of Canada, Alaska and Greenland
No full textDistributional checklists of the extant, described species of five superfamilies of Hymenoptera of Canada, Alaska and Greenland are presented. In total, 296 species in 79 genera in 12 families are recorded: 55 species of Ceraphronoidea, classified in 10 genera in 2 families, 205 species of Cynipoidea in 58 genera in 5 families, 30 species of Evanioidea in 5 genera in 3 families of Evanioidea, 2 species of Stephanoidea in 2 genera in 1 family and 4 species of Trigonalyoidea in 4 genera in 1 family. Of the reported species, 281 (in 79 genera in 12 families) are listed from Canada, 31 (in 16 genera in 6 families) from Alaska, and 7 (in 5 genera in 2 families) from Greenland. The list includes 8 new generic records for Canada (1 Ceraphronoidea, 6 Cynipoidea and 1 Evanioidea) and 43 new Canadian species records (13 Ceraphronoidea, 28 Cynipoidea and 2 Evanioidea). For each species in Canada, distribution is tabulated by province or territory, except the province of Newfoundland and Labrador is divided into the island of Newfoundland and the region of Labrador. These checklists are compared with previous Nearctic and Palaearctic surveys, checklists and catalogues. Kleidotoma minima Provancher, 1883 (Figitidae) is moved from this genus to Hexacola Förster, 1869 to form H. minimum (Provancher, 1883), comb. nov. Amblynotus slossonae Crawford, 1917 (Figitidae) is moved from Melanips Walker, 1835 to Amphithectus Hartig, 1840 forming A. slossonae (Crawford, 1917), comb. nov.
Late Cretaceous and Early Paleogene Fluid Circulation and Microbial Activity in Deep Fracture Networks of the Precambrian Basement of Western Greenland
No full textDeep fracture-hosted fluids of Precambrian bedrock cratons are relatively stagnant over long time spans compared to near-surface systems. However, episodic events, such as fracture reactivations, transgressions, and deglaciations, may introduce dilute water, replacing, and mixing with the deep continental brines, thereby sparking microbial activity. Secondary minerals that line bedrock fractures serve as important geochemical archives for such episodic events. Here we explore the fracture mineral record of Archean rocks of Western Greenland by analyzing samples from deep boreholes with the aim to trace and characterize episodic paleofluid flow and paleomicrobial activity. A sequence of hydrothermal to low temperature fluid flow events is demonstrated. For the youngest generation, microscale S-isotope analysis of pyrite reveals substantial 34S-depletion (minimum δ34S:−58‰V-CDT) compared to fracture-hosted barite (δ34S:13‰ ± 2‰) and gypsum (δ34S:2.6‰–10.6‰). This suggests the formation of pyrite following S isotope fractionation during microbial sulfate reduction. This metabolism is further indicated by several methyl-branched fatty acids preserved in calcite. A general discrepancy between calcite and groundwater δ18O-values suggests that calcite formed from water different from the presently residing glacial meltwater-influenced groundwater mix. High spatial resolution U-Pb carbonate geochronology of the youngest generation of calcite yielded ages for two samples: 64 ± 3, 75 ± 7 Ma (2σ). These ages overlap with tectonic events related to early stages, or prestages, of the opening of the Atlantic and Labrador Seas. This suggests that deep fracture networks in Western Greenland were colonized by microorganisms, such as sulfate reducers, in the course of this extensional event
Effects of livestock on arthropod biodiversity in Iberian holm oak savannas revealed by metabarcoding
No full textIncreasing food production while avoiding negative impacts on biodiversity constitutes one of the main challenges of our time. Traditional silvopastoral systems like Iberian oak savannas (“dehesas”) set an example, where free-range livestock has been reared for centuries while preserving a high natural value. Nevertheless, factors decreasing productivity need to be addressed, one being acorn losses provoked by pest insects. An increased and focalized grazing by livestock on infested acorns would kill the larvae inside and decrease pest numbers, but increased livestock densities could have undesired side effects on ground arthropod communities as a whole. We designed an experimental setup including areas under trees with livestock exclosures of different ages (short-term: 1-year exclusion, long-term: 10-year exclusion), along with controls (continuous grazing), using DNA metabarcoding (mitochondrial markers COI and 16S) to rapidly assess arthropod communities’ composition. Livestock removal quickly increased grass cover and arthropod taxonomic richness and diversity, which was already higher in short-term (1-year exclosures) than beneath the canopies of control trees. Interestingly, arthropod diversity was not highest at long-term exclosures (≥10 years), although their community composition was the most distinct. Also, regardless of treatment, we found that functional diversity strongly correlated with the vegetation structure, being higher at trees beneath which there was higher grass cover and taller herbs. Overall, the taxonomic diversity peak at short term exclosures would support the intermediate disturbance hypothesis, which relates it with the higher microhabitat heterogeneity at moderately disturbed areas. Thus, we propose a rotatory livestock management in dehesas: plots with increased grazing should co-exist with temporal short-term exclosures. Ideally, a few long-term excluded areas should be also kept for the singularity of their arthropod communities. This strategy would make possible the combination of biological pest control and arthropod conservation in Iberian dehesas
