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The early land plant Cooksonia bohemica from the Pridoli, late Silurian, Barrandian area, the Czech Republic, Central Europe
No full textCooksonia bohemica Schweitzer (= Aberlemnia bohemica (Schweitzer) Sakala, Pšenička et Kraft) from Přídolí strata of the Barrandian area in the Czech Republic is revised, and its morphology is documented in detail. The holotype bears sporangia that, although reniform, do not possess a slit that would allow valvate opening as assumed in earlier studies. Its axes do not show consistent shortening of segments towards the distal portion of the plant as is typical for Aberlemnia Gonez et Gerrienne. The axes contain tubular structures interpreted here as cells of conducting tissues. Masses of subtriangular trilete spores with equatorial crassitudo and finely microgranulate sculpture are of the Ambitisporites type. Cooksonia bohemica is compared with all species of Cooksonia Lang described previously. Additionally, comparisons are made with the related genus Aberlemnia. Based on studies of the type material of both taxa, we suggest retaining the species in Cooksonia. Cooksonia bohemica is differentiated from other taxa based on a combination of branching pattern, sporangial shape, and spore morphology. The remains are interpreted to be the sporophyte of an early land plant referable to tracheophytes based on the presence of vascular strands in its axes. A general radiation of cooksonioids away from a core region around the Rheic Ocean is proposed for the Silurian–Devonian transition.This work was supported by the Czech Science Foundation [21-10799S], and the research plan of the Institute of Geology of the Czech Academy of Sciences, v.v.i., [RVO67985831]. SM is funded by a grant from Vetenskapsrådet [2018-04527]. </p
Emendment to the term complex in: “Guide for geological nomenclature in Sweden” (Kumpulainen 2016)
No full textSince the publication of Kumpulainen (2016), the Committeehave been alerted by the investigation and subsequent changesto the North American Stratigraphic Code concerning thelithodemic unit“complex”(Easton et al.2016; North Ameri-can Commission on Stratigraphic Nomenclature (NACSN)2017). These changes concern the introduction of the nomen-clature unit“Intrusive Complex”. In the original version(NACSN1983), as well as in the Swedish Guide for nomencla-ture (Kumpulainen2016), the unit“complex”is defined ascontaining at least two genetic classes of rocks, i.e., igneous,sedimentary, or metamorphic
Seals, whales and the Cenozoic decline of nautiloid cephalopods
No full textNautilus and Allonautilus, last members of the once widespread nautiloid cephalopods, are today restricted to the deep central Indo-West Pacific Ocean, for reasons that remain unclear. Cephalopod evolution is generally considered as being driven by vertebrate predation; therefore, we investigated the role of whales and seals in the decline of nautiloids through the Cenozoic.Financial support to SK was provided by the Swedish Research Council (Vetenskapsrådet) through grant 2016-03920, and to CHT by the Taiwan Ministry of Science and Technology through grant MOST 108-2621-B-002-006-MY3.</p
Paleovegetation and paleoclimate inferences of the early late Sarmatian palynoflora from the Gleisdorf Fm. at Gratkorn, Styria, Austria
No full textThe Gleisdorf Formation (Fm.) deposits in the clay pit at Gratkorn, Styria, Austria, are dated to 12.2–12 Ma,and are of late Middle Miocene age (late Serravallian or Sarmatian). To reconstruct the paleovegetation and estimate the paleoclimate at this important vertebrate site, the palynoflora close to the boundary between the vertebrate-bearing layers of the Gratkorn Fm. and the overlying limnic clay deposits of the Gleisdorf Fm. was investigated. Using the single-grain method, 140 palynomorphs were identified. The palynoflora suggests that the paleovegetation was characterised by well-drained lowland and upland forests, riparian forest, and swamp forests. Depending on the dominating tree species, lowland and upland forests might have had closed or more open canopies. Open habitats included wet meadows and shrublands. In addition, conifers were present in theswampy lowlands and the forested uplands. The most prominent paleoclimatic signatures of the palynoflora indicate a fully humid warm temperate climate, with hot to warm summers and cool winters (Cfa-, Cfb-climate), and a seasonal climate with cool and drier winters and hot to warm and wetter summers (Cwa-, Cwb-climate). Our results align with existing studies bordering the Styrian Basin and support the presence of subtropical to warm-temperate vegetation around Gratkorn during the Sarmatian
Speciation and population divergence in a mutualistic seed dispersing bird
No full textBird-mediated seed dispersal is crucial for the regeneration and viability of ecosystems, often resulting in complex mutualistic species networks. Yet, how this mutualism drives the evolution of seed dispersing birds is still poorly understood. In the present study we combine whole genome re-sequencing analyses and morphometric data to assess the evolutionary processes that shaped the diversification of the Eurasian nutcracker (Nucifraga), a seed disperser known for its mutualism with pines (Pinus). Our results show that the divergence and phylogeographic patterns of nutcrackers resemble those of other non-mutualistic passerine birds and suggest that their early diversification was shaped by similar biogeographic and climatic processes. The limited variation in foraging traits indicates that local adaptation to pines likely played a minor role. Our study shows that close mutualistic relationships between bird and plant species might not necessarily act as a primary driver of evolution and diversification in resource-specialized birds
Paleobotanical research in Ukraine
No full textPalaeobotanical research in Ukraine has a history of more than one hundred and fifty years, which is calculated from the time of publication (1872) of the work of A.V. Gurov “Fossil organic remains of Donetsk coal deposits”. The research was conducted by scientists from Kyiv, Lviv, Luhansk, Chernihiv, Dnipropetrovsk, Artemivsk. The most numerous was the team of palaeobotanists of the Institute of Geological Sciences of the National Academy of Sciences of Ukraine, headed by the corresponding member E.O. Novik. The stratigraphy of carbonaceous deposits, patterns in the development of the coal flora, and issues of coal accumulation were the areas that were developed under her leadership by experts, such as O.I. Anisimova, T.A. Ishchenko, O.P. Fisunenko and O.K. Shchogolev. Mesozoic and Cenozoic floras were studied by E.E. Mihacheva, F.А. Stanislavsky, Yu.V. Teslenko, N.Ya. Shvaryova and others. The great work of the academician of the USSR, A.M. Kryshtofovych, is the book “Paleobotany”, which includes numerous discoveries of fossil plants from Ukrainian sections. A significant contribution to the development of palaeobotany in Ukraine, its theoretical foundations, and methodology was made by professors O.P. Fisunenko and O.K. Shchogolev. O.P. Fisunenko dealt with the theory and methodology of stratigraphy, analysis of the natural-philosophical problem of time in geology, in seeing the path of detailed development of stratigraphy through the Phanerozoic, taking into account the general laws of evolution of the biota and crust. O.K. Shchogolev initiated a new synthetic biological-geological-geographical scientific direction in palaeobotany–paleophytogeocenology. O.P. Gubskaya studied the plant communities of the Bashkirian and Moscovian (Carboniferous) stages of Donbas. A.A. Ishchenko studied the Silurian algae flora and the Kuksonia flora of Volyn-Podillya. F.A. Stanislavsky’s works on the Triassic leaf flora and middle Jurassic of the north-western outskirts of Donbas have received worldwide recognition. Yu.V. Teslenko studied the flora of the Jurassic and Cenozoic, developed the concept of phased development of the Earth’s vegetation depending on changes in the chemical composition of the atmosphere. He established the vertical botanical and geographical zonation of the eastern regions of the Tethys and Paratethys in the Miocene and Pliocene. The Cenomanian flora near the town of Kaniv (Ukrainian Shield, Central Ukraine) was studied in 1939 by N.V. Pimenova. Later, M.P. Doludenko, E.I. Kostina and I.A. Shilkina attributed this flora to the late Albian. Also, notable are the achievements of Ukrainian paleobotanists L.T. Malyshko and S.O. Molchanov, who studied the Eocene, Oligocene and Neogene floras of the western territory of Ukraine. Today palaeobotanists of the Institute of Geological Sciences of the National Academy of Sciences of Ukraine are working actively. This team includes N.I. Boyarina, who studies the flora of the Palaeozoic and A.I. Martyshyn, who studies the Ediacaran biota. Also, V.P. Hrytsenko has made great achievements in the study of the Ediacarian algae of Podillya (southwestern Ukraine) from the National Science and Natural History Museum of the National Academy of Sciences of Ukraine. Currently, the Paleontological Museum of the Taras Shevchenko National University, namely the Institute of Geology, has a collection of late Albian–Cenomanian plants from the outskirts of Kaniv. This collection is replenished and studied by teachers and students during their annual research internships in this region (Popova, Moroz, 2010). We have recently launched a comprehensive palaeobotanical and palynological research program in Ukraine. Thus, the Bathonian deposits of the north-western outskirts of Donbas (Shevchuk, Slater, Vajda, 2018), the upper Albian-Cenomanian deposits from central part of the Ukrainian Shield (Shevchuk, 2021) were studied
Mitogenomics and hidden‐trait models reveal the role of phoresy and host shifts in the diversification of parasitoid blister beetles (Coleoptera: Meloidae)
No full textChanges in life history traits are often considered speciation triggers and can have dramatic effects on the evolutionary history of a lineage. Here, we examine the conse-quences of changes in two life history traits, host-type and phoresy, in the hypermeta-morphic blister beetles, Meloidae. Subfamilies Nemognathinae and Meloinae exhibit a complex life cycle involving multiple metamorphoses and parasitoidism. Most gen-era and tribes are bee- parasitoids, and include phoretic or nonphoretic species, while two tribes feed on grasshopper eggs. These different life strategies are coupled with striking differences in species richness among clades. We generated a mitogenomic phylogeny for Nemognathinae and Meloinae, confirming the monophyly of these two clades, and used the dated phylogeny to explore the association between diver-sification rates and changes in host specificity and phoresy, using state-dependent speciation and extinction (SSE) models that include the effect of hidden traits. To account for the low taxon sampling, we implemented a phylogenetic-taxonomic ap-proach based on birth-death simulations, and used a Bayesian framework to integrate parameter and phylogenetic uncertainty. Results show that the ancestral hypermet-amorphic Meloidae was a nonphoretic bee- parasitoid, and that transitions towards a phoretic bee- parasitoid and grasshopper parasitoidism occurred multiple times. Nonphoretic bee- parasitoid lineages exhibit significantly higher relative extinction and lower diversification rates than phoretic bee-and grasshopper- parasitoids, but no significant differences were found between the latter two strategies. This suggests that Orthopteran host shifts and phoresy contributed jointly to the evolutionary suc-cess of the parasitoid meloidae. We also demonstrate that SSE models can be used to identify hidden traits coevolving with the focal trait in driving a lineage's diversifica-tion dynamics
