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Cretaceous (Albian–Coniacian) dinoflagellate biostratigraphy of the Vomb Trough, southern Sweden
No full textWe document diverse and well-preserved dinoflagellate cyst assemblages from Cretaceous successions in the Kullemölla 1 drill core (640.0 m–590.0 m), Vomb Trough, southern Sweden. Palynology reveals a nearshore marine environment. Dinoflagellate index taxa indicate an Albian to Coniacian age, thus spanning the Early–Late Cretaceous boundary. The lower part of the core is Albian, based on the presence of the index dinocyst taxa Pareodinia and Callaiosphaeridium asymmetricum. The First Appearance Datum (FAD) of Oligosphaeridium prolixispinosum, together with the presence of Achomosphaera ramulifera, Heterosphaeridium difficile and Oligosphaeridium pulcherrimum, reveals a Cenomanian age for the interval 635– m–617 m. The Turonian interval is characterized by an increase in the dinocysts Chatangiella spectabilis and Florentinia spp., in combination with the FAD of Senoniasphaera rotundata, whereas the youngest samples are dated to the Coniacian as defined by the appearance of Glaphyrocysta sp. We show that Cenomanian and Turonian strata are indeed represented by a relatively condensed section between 635 m and 612 m in the Kullemölla 1 core showing that the apparent hiatus recorded by calcareous microfossils elsewhere is likely a result of post-depositional dissolution of calcareous tests and limestone, a process that did not affect the organic-walled plankton. This is further supported by the presence of hardgrounds and dissolution features. This updated, detailed biostratigraphical assessment based on dinoflagellates provides a framework for correlation with zonations based on other marine fossil groups, useful, for e.g., correlating aquifers in subsurface successions and, further, provides opportunities for linking marine and continental biotas.This work was supported by Swedish Foundation for Strategic Research, grants for Ukrainian scientists 2022 [grant number UKR22-0020].</p
Plant colonization of isolated palaeoecosystems: Palynology of a Middle Jurassic extinct volcanic island (Camarena, Teruel, eastern Spain)
No full textPalynological assemblages from palaeo-islands are scarce in the fossil record and represent an opportunity to explore plant dispersal patterns and colonization strategies in isolated ecosystems. We present a palynological study of a Middle Jurassic volcanic island located in a shallow epicontinental sea, c. 150 km from the palaeomainland. The study is based on a 2-m thick succession of calcareous marlstones in the El Pedregal Formation in the eastern part of the Iberian Basin, and the palaeo-island is termed Camarena Island after the village nearest to the fossil site. Eleven samples yielded equivalent assemblages that are here treated as a single palynological suite containing 47 fossil-species belonging to 36 fossil-genera. The abundance of Araucariacites australis and Klukisporites variegatus, together with accessory Cycadopites spp. and the scarcity of Callialasporites turbatus, Manumia irregularis, Staplinisporites caminus and Kekryphalospora distincta, suggest a Toarcian–Aalenian age. Additional stratigraphical data resolve the likely age for the Camarena Island as lower–middle Aalenian. Many palynomorphs in this assemblage have apparent anemophilous and hydrophilous adaptations facilitating long distance transport. On this basis, some parent plants probably derive from the adjacent mainland or neighbouring islands. Marine palynomorphs or pollen and spores with few adaptations for dispersal may have derived from plant groups that evolved in situ on the volcanic island. The palynological assemblage has some differences from coeval palynofloras from the central Iberian Peninsula, but there are also some similarities with assemblages from post-volcanic deposits and other oceanic islands. It is likely that the seaway separating the volcanic island from the mainland acted as a biological filter enabling colonization by only a selected range of plant groups.This research was supported by the project PGC2018-094034-B-C22 of the “Ministerio de Ciencia, Innovaci´on y Universidades” of Spain and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB26000000) for support. AAS is supported by a postdoctoral fellowship from the UNAM (Mexico, ref.: UNAM-DGAPA 2023-2024) and a subsequent fellowship funded from the Swedish Research Council Grant VR 2022-03920 to SM. AAS and IRB were supported by predoctoral fellowships from the Xuntade Galicia (Spain) and the European Social Fund-European Union (ref.:ED481A-2020/175). This report also contributes to the University of Valencia Research Group GIUV2017-395.</p
Fossil and modern penguin tarsometatarsi: cavities, vascularity, and resilience
No full textPenguin tarsometatarsi are shortened and flattened, and studies devoted to the internal characteristics of these composite bones are very limited. Therefore, we present here a comprehensive, x-ray-microscopy-based analysis based on tarsometatarsi of Eocene stem Sphenisciformes from Seymour Island (Antarctic Peninsula) as well as recent Aptenodytes forsteri, A. patagonicus, and Pygoscelis adeliae penguins. Our study focuses on four aspects: size variability of the medullary cavities, vascularization patterns with emphasis on diaphyseal vessels, cross-sectional anisotropy, and diaphyseal resistance to bending forces. Small-sized Eocene penguins (Delphinornis and Marambiornopsis) show well-developed tarsometatarsal medullary cavities, whereas the cavities of “giant” early Sphenisciformes are either smaller (Palaeeudyptes) or show a conspicuous intermetatarsal size gradient (Anthropornis). Extant penguins exhibit a decrease in cavity dimensions as their body size increases. Distributional tendencies of primary diaphyseal nutrient foramina are quite similar in the smaller Delphinornis, Marambiornopsis, and extant Pygoscelis on one side and in Palaeeudyptes and extant Aptenodytes on the other. Anthropornis shows a unique, plesiomorphic pattern with a prevalence of plantar blood supply to the metatarsals. The diaphyseal nutrient canals diverge in orientation, some obliquely away from the proximal part, others with disparate trajectories. Cross-sectional anisotropy along the tarsometatarsal shaft generally appears to be rather low. Clustering of coherency curves along certain tarsometatarsal segments may reflect a selection process that exerts a significant influence within biomechanically crucial sections. Diaphyseal resistance to mediolateral bending forces is explicitly more efficient in extant penguins than in Eocene Sphenisciformes. This can be interpreted as an adaptation to the waddling gait of extant penguins. XRM data acquisition was supported by a grant to the Stockholm University Brain Imaging Centre (SU FV-5.1.2-1035-15). Financial support for XRM scanning was provided by Vivi Vajda (Swedish Museum of Natural History)</p
The palaeobotanical heritage of Ukraine and its endangered status following the Russian military invasion
No full textUkraine has a rich Proterozoic to Quaternary fossil record of photosynthetic microbes and plants. Particularly rich and scientifically important fossils of early multicellular organisms have been documented from the Ediacaran, early land plants from the Silurian–Devonian, coal-forming floras from the Carboniferous, typical post-extinction recovery vegetation and coal swamp forests from the Triassic and Jurassic, and well-preserved angiosperms and conifers from the Cretaceous and Cenozoic. These fossil floras help elucidate the temporal changesin the vegetation at the junction of Europe, Asia and the Tethyan microcontinental terranes and highlight biogeographic linkages between various floral provinces through deep time. The rich and variably preserved floras offer great scope for further taxonomic, palaeoecological, palaeoclimatic and biogeographic research. Extensive fossil collections are stored in several major institutional repositories scattered across Ukraine. Some of these institutions have now been occupied by Russian forces, and others have been damaged and remain under threat, risking potential loss for future research. The impact of the war on Ukrainian museums and scientific collections has implications for how fossil specimens are stored and what procedures are enacted to preserve collections in other parts of the world in the event of war, civil disturbance, or natural disasters.Olena Shevchuk is a recipient of a Swedish Foundation for Strategic Research (SSF) individual research grant (2022–2024). She also acknowledges funding from a 2022 Sepkoski Grant of the American Union of Paleontologists for the implementation of scientific work on the topic: “Palynostratigraphy of the Triassic–Jurassic transition of the north- western outskirts of Donbas”. Olena Shevchuk, Natalia Boyarina, Oleg Sukhov are additionally supported by the Institute of Geological Sciences of the National Academy of Sciences of Ukraine, Kyiv, Ukraine. Funding is also acknowledged from the Knut and Alice Wallenbergs stiftelse KAW 2020.0145 (to V.V.), and Swedish Research Council VR grants 2019–4061 (to V.V.) and 2022–03920 (to S.M.). The authors declare no other competing interests. This paper is part of ongoing work to enhance stratigraphic correlation and strengthen research collaboration between Swedish and Ukrainian geoscientists. Olena Shevchuk is a recipient of two Swedish Foundation for Strategic Research (SSF) individual research grants (2022–2025). She also acknowledges funding from a 2022 Sepkoski Grant of the American Union of Paleontologists for the implementation of scientific work on the topic: “Palynostratigraphy of the Triassic–Jurassic transition of the north-western outskirts of Donbas”. Olena Shevchuk, Natalia Boyarina, Oleg Sukhov are additionally supported by the Institute of Geological Sciences of the National Academy of Sciences of Ukraine, Kyiv, Ukraine. Funding is also acknowledged from the Knut and Alice Wallenbergs stiftelse KAW 2020.0145 (to V.V.), and Swedish Research Council VR grant 2022-03920 (to S.M.).</p
European pollen reanalysis, 1980–2022, for alder, birch, and olive
No full textThe dataset presents a 43 year-long reanalysis of pollen seasons for three major allergenic genera of trees in Europe: alder (Alnus), birch (Betula), and olive (Olea). Driven by the meteorological reanalysis ERA5, the atmospheric composition model SILAM predicted the fowering period and calculated the Europe-wide dispersion pattern of pollen for the years 1980–2022. The model applied an extended 4-dimensional variational data assimilation of in-situ observations of aerobiological networks in 34 European countries to reproduce the inter-annual variability and trends of pollen production and distribution. The control variable of the assimilation procedure was the total pollen release during each fowering season, implemented as an annual correction factor to the mean pollen production. The dataset was designed as an input to studies on climate-induced and anthropogenically driven changes in the European vegetation, biodiversity monitoring, bioaerosol modelling and assessment, as well as, in combination with intra-seasonal observations, for health-related applications
SNP‐based analysis of European Thymallus spp. (Salmonidae) reveals extensive mito‐nuclear discordance relevant for biogeographic inferences, taxonomy and conservation
No full textAn evaluation of the usefulness of morphological characters to infer higher-level relationships in birds by mapping them to a molecular phylogeny
No full textThe use of genetic data to reconstruct systematic relationships has revolutionized our understanding of avian evolution. Morphology-based classifications were often in conflict because of different opinions among scholars about the relative importance of certain phenotypes. The considerable morphological variation observed among birds was codified into phylogenetic characters by Livezey and Zusi (2006) who also scored them for 150 extinct and extant taxa. Herein we have evaluated the phylogenetic signal of 1860 of these characters by mapping them to a molecular phylogeny including 102 taxa that represent all extant birds (with the underlying assumption that this tree topology is a good estimate of the evolutionary relationships among birds). The characters fit the molecular tree with a mean consistency index (CI) of 0.38. Muscle characters are the most homoplasious (CI 0.32), while characters related to integument, feathers, intestinal, respiratory, syrinx, urogenital, nervous, and reproductive organs show a considerably better fit (mean CI 0.49). We also explored what characters may unambiguously support certain basal clades that are well-supported by molecular data. We found only a few clades (e.g. Galloanserae, Procellariimorphae) being supported by unambiguous apomorphies, while many well-established clades (e.g. Pelecaniformes, Charadriiformes, Accipitriformes, Coraciiformes) lack such support entirely
A new species of nightjar (Caprimulgus) from Timor and Wetar, Lesser Sunda Islands, Wallacea
No full textThe nightjars of the Caprimulgus macrurus complex are distributed from Pakistan to Australia and comprise six morphologically similar but vocally distinct species. Fieldwork on Timor and Wetar, Lesser Sunda Islands, has resulted in the discovery of a seventh species in the complex, which we describe as a new species. This species has previously been confused with Caprimulgus macrurus, Caprimulgus celebensis and Caprimulgus manillensis but it differs from these and all other species in the complex by at least 13 vocal characters. Discriminant function analysis correctly classified all recordings in the complex to species. Caprimulgus ritae is known from five adult museum specimens, which are the smallest in the complex and which differ from other species in the complex in several morphological characters. A molecular phylogenetic analysis indicated that C. ritae is sister to C. meesi from Flores and Sumba, and that these species together are sister to C. macrurus. C. ritae is a tropical forest specialist occurring from sea level to at least 1500 m (probably mostly below 1000 m). Lowland and montane forests on Timor are threatened. Wetar is one of the least developed islands in Indonesia, and retains >95% natural vegetation, dominated by Eucalyptus woodlands, with tropical forests in river gorges and slopes in upland areas. Pressure for development is accelerating throughout the range of C. ritae, and a detailed assessment of its conservation status is urgently needed
Tubule system of earliest shells as a defense against increasing microbial attacks
No full textThe evolutionary mechanism behind the early Cambrian animal skeletonization was a complex and multifaceted process involving environmental, ecological, and biological factors. Predation pressure, oxygenation, and seawater chemistry change have frequently been proposed as the main drivers of this biological innovation, yet the selection pressures from microorganisms have been largely overlooked. Here we present evidence that calcareous shells of the earliest mollusks from the basal Cambrian (Fortunian Age, ca. 539–529 million years ago) of Mongolia developed advanced tubule systems that evolved primarily as a defensive strategy against extensive microbial attacks within a microbe-dominated marine ecosystem. These high-density tubules, comprising approximately 35% of shell volume, enable nascent mineralized mollusks to cope with increasing microbial bioerosion caused by boring endolithic cyanobacteria, and hence represent an innovation in shell calcification. Our finding demonstrates that enhanced microboring pressures played a significant role in shaping the calcification of the earliest mineralized mollusks during the Cambrian Explosion.This study was funded by the National Natural Science Foundation of China (grants 41930319, 41890845, 42121005, 41890844, 42202001, and 42072003); the China Postdoctoral Science Foundation (grant 2022M712987); and the Swedish Research Council (grants VR2016-04610, VR2017-05183, and VR2021-04295). </p
