Hasil untuk "Paleontology"

Markéta Harazim, Lubomír Piálek, Hana Bandouchova et al.

Hibernation profoundly alters host–pathogen dynamics by suppressing metabolism and immune function, posing unique challenges for infection control. In this study, we examined how genomic variation modulates infection and physiological traits in temperate bats during hibernation. We combined infection screening, haematology, blood biochemistry, and whole-genome sequencing across five vespertilionid species, identifying over 170,000 single nucleotide variants (SNVs) and assessing their associations with 23 health-related variables. Using the phylogenetically informed treeWAS framework, we detected 515 significant SNVs linked to traits including fungal, protozoan and bacterial infections, acid–base balance, and blood cell indices. These SNVs mapped to 137 unique genes, which were enriched for functional domains related to cytoskeletal dynamics, membrane trafficking, and intracellular signalling (e.g., SH3, C2, BAR, semaphorin). Notably, canonical immune effector genes were underrepresented, and several trait-associated SNVs appeared in blocks across multiple scaffolds, pointing to regulatory loci as key modulators of hibernator health. Our findings support the hypothesis that bats rely on infection tolerance rather than resistance during hibernation, with genomic variation in regulatory and signalling pathways shaping their physiological responses to infection under energy-limited conditions.

Yangui Li, Chunbo Yan, Chuanshang Wang et al.

Abstract Silurian strata are well-developed in the northwest margin of Yangtze Platform. A total of 117 densely spaced argillaceous samples were taken from the Shenxuanyi Member, upper Ningqiang Formation to the lowermost Chejiaba Formation of the Majia section in northern Sichuan Province. The main aim of this study is to obtain chitinozoans to test whether Wenlock deposits are preserved here. A highly diverse and abundant chitinozoan assemblage is documented, including 21 species from six genera. This assemblage was then compared to contemporaneous chitinozoan assemblages reported from adjacent areas. This study proposes that Eisenackitina venusta (corresponds to the Pterospathodus celloni conodont Biozone) is of chronostratigraphical significance for discussing the Telychian of the Yangtze region. It is suggested that the Silurian upper red bed (lower part of the Shenxuanyi Member) in the study area is younger than the Xiushan Formation and can be correlated with the Huixingshao Formation of the Central Yangtze Platform. There are no index chitinozoan species near the Llandovery–Wenlock boundary that have been found in the upper part of the Shenxuanyi Member, and the updated chronostratigraphic framework suggests that it is Telychian-aged deposits.

H. Hess, C. Messing, W. Ausich

Mark T. Young, Julia A. Schwab, David Dufeau et al.

During major evolutionary transitions, groups develop radically new body plans and radiate into new habitats. A classic example is cetaceans which evolved from terrestrial ancestors to become pelagic swimmers. In doing so, they altered their air-filled sinuses, transitioning some of these spaces to allow for fluctuations in air capacity and storage via soft tissue borders. Other tetrapods independently underwent land-to-sea transitions, but it is unclear if they similarly changed their sinuses. We use computed tomography to study sinus changes in thalattosuchian crocodylomorphs that transformed from land-bound ancestors to become the only known aquatic swimming archosaurs. We find that thalattosuchian braincase sinuses reduced over their transition, similar to cetaceans, but their snout sinuses counterintuitively expanded, distinct from cetaceans, and that both trends were underpinned by high evolutionary rates. We hypothesize that aquatic thalattosuchians were ill suited to deep diving by their snout sinuses, which seem to have remained large to help drain their unusual salt glands. Thus, although convergent in general terms, thalattosuchians and cetaceans were subject to different constraints that shaped their transitions to water. Thalattosuchians attained a stage similar to less pelagic transitional forms in the cetacean lineage (late protocetid-basilosaurid) but did not become further specialized for ocean life.

Yuzhi Hu, Ajay Limaye, Jing Lu

3D visualization and segmentation are increasingly widely used in physical, biological and medical science, facilitating advanced investigative methodologies. However, the integration and reproduction of segmented volumes or results across the spectrum of mainstream 3D visualization platforms remain hindered by compatibility constraints. These barriers not only challenge the replication of findings but also obstruct the process of cross-validating the accuracy of 3D visualization outputs. To address this gap, we developed an innovative revisualization method implemented within the open-source framework of Drishti, a 3D visualization software. Leveraging four animal samples alongside three mainstream 3D visualization platforms as case studies, our method demonstrates the seamless transferability of segmented results into Drishti. This capability effectively fosters a new avenue for authentication and enhanced scrutiny of segmented data. By facilitating this interoperability, our approach underscores the potential for significant advancements in accuracy validation and collaborative research efforts across diverse scientific domains.

Francesc Pérez-Peris, Jonathan M. Adrain, Allison C. Daley

Abstract Cheiruridae is one of the most diverse families of trilobites known from the Ordovician with 453 species assigned. Within Cheiruridae eight subfamilies (Acanthoparyphinae, Cheirurinae, “Cyrtometopinae”, Deiphoninae, Eccoptochilinae, Heliomerinae, Pilekiinae, and Sphaerexochinae) have historically been recognised. Insights about the evolution of the family and the relationships within and between subfamilies have been published. However larger scale phylogenetic hypotheses are needed in order to explore the monophyly, the basal structure, the deep nodes and the relationships of the subfamilies. Cheirurinae, Deiphoninae and “Cyrtometopinae” have historically been defined by various morphological features (e.g., anteroposterior constriction of the thoracic pleura, pleural furrow morphology, pygidial morphology) that differentiate them from the rest of Cheiruridae. However, the phylogenetic status of “Cyrtometopinae” is unclear owing to a lack of obvious synapomorphies. Here, we present phylogenetic analyses of Cheirurinae, Deiphoninae, and “Cyrtometopinae”. The results indicate that both Cheirurinae and Deiphoninae are monophyletic. “Cyrtometopines” are resolved as a paraphyletic grade at the base of Deiphoninae and Cyrtometopinae should be considered a junior subjective synonym of Deiphoninae. The new phylogenetic hypothesis reveals that paedomorphosis plays an important role in the evolution of Deiphoninae. Within Cheirurinae two major clades are identified, the ‘Ceraurus-like’ clade and the ‘Ceraurinella-like’ clade.

Yan‐Da Li, Jiří Kolibáč, Zhen‐Hua Liu et al.

Abstract Beetles have a remote evolutionary history dating back to the Carboniferous, with Mesozoic fossils playing a pivotal role in elucidating the early evolution of extant families. Despite their exceptional preservation in amber, deciphering the systematic positions of Mesozoic trogossitid‐like beetles remains challenging. Here, we describe and illustrate a new trogossitid‐like lineage from mid‐Cretaceous Kachin amber, Foveapeltis rutai Li, Kolibáč, Liu & Cai, gen. et sp. nov. Foveapeltis stands out within the Cleroidea due to the presence of a significant large cavity on each hypomeron. While the exact phylogenetic placement of Foveapeltis remains uncertain, we offer a discussion on its potential affinity based on our constrained phylogenetic analyses.

G. Wefer, W. Berger

Case Vincent Miller, Michael Pittman, Xiaoli Wang et al.

Summary: The diet of Mesozoic birds is poorly known, limiting evolutionary understanding of birds’ roles in modern ecosystems. Pengornithidae is one of the best understood families of Mesozoic birds, hypothesized to eat insects or only small amounts of meat. We investigate these hypotheses with four lines of evidence: estimated body mass, claw traditional morphometrics, jaw mechanical advantage, and jaw finite element analysis. Owing to limited data, the diets of Eopengornis and Chiappeavis remain obscure. Pengornis, Parapengornis, and Yuanchuavis show adaptations for vertebrate carnivory. Pengornis also has talons similar to living raptorial birds like caracaras that capture and kill large prey, which represents the earliest known adaptation for macrocarnivory in a bird. This supports the appearance of this ecology ∼35 million years earlier than previously thought. These findings greatly increase the niche breadth known for Early Cretaceous birds, and shift the prevailing view that Mesozoic birds mainly occupied low trophic levels.

Yu Qiao, Jun Liu, Andrzej S. Wolniewicz et al.

Further evidence for an explosive marine reptile diversification event in the Early Triassic is presented via morphological analysis of a new Sclerocormus specimen.

Marcelo Saúl de la Fuente

Las dos instituciones más relevantes dedicadas a la promoción de las ciencias naturales en el sur de la provincia de Mendoza son el Museo de Historia Natural de San Rafael (MHNSR) (Departamento de San Rafael) y el Museo Regional de Malargüe “Jorge Luna” (MRM) (Departamento de Malargüe). La primera institución fue fundada en el año 1955 mientras que la segunda se erigió en el año 1973 y ambas se incorporaron a la órbita municipal en los primeros años de la década del ‘70 del siglo pasado. Estos museos han tenido un diferente desarrollo y proyección en lo que respecta a su actividad científica. Esto también se reflejó en el desarrollo de la paleoherpotología en el MHNSR con la incorporación de investigadores y becarios del CONICET acontecida a partir del año 2002. En el año 2006 se originó el Centro Regional de Investigación y Desarrollo Cultural, institución que desarrolló actividades paleontológicas en Malargüe principalmente entre los años 2006 y 2015. Con la reciente creación del Instituto de Evolución, Ecología Histórica y Ambiente, unidad ejecutora de doble dependencia CONICET y Universidad Tecnológica Nacional, los paleontólogos continuaron su desempeño en esta unidad sin dejar el MHNSR, donde se alojan las colecciones paleontológicas. En el MRM, las colecciones se encuentran tanto en el antiguo molino del casco de la estancia “La Orteguina”, edificación colindante, y en la sala de exposición de paleontología de dicho museo. Estas instituciones resguardan pequeñas colecciones de reptiles fósiles.

STEFANO VISENTIN, ELISABETTA ERBA

Calcareous nannofossil biostratigraphy was conducted across the Toarcian Oceanic Anoxic Event (T-OAE) interval cored at Colle di Sogno and Gajum in the Lombardy Basin (Southern Alps, Northern Italy). Drilling at both sites resulted in 100% recovery of unweathered material. The Sogno and Gajum Cores consist of pelagic marly limestones, marlstone, marly claystone, and a relatively expanded black shale interval named Fish Level considered the lithostratigraphic record of the T-OAE at regional scale. Semiquantitative analyses of calcareous nannofloras allowed to achieve a high-resolution biostratigraphy of the latest Pliensbachian-early Toarcian time interval. Several nannofossil biohorizons were detected, including zonal/subzonal markers and additional events related to changes in abundance. The nannofossil biostratigraphic correlation of the Sogno and Gajum Cores indicates that, according to their paleogeographic settings, the succession recovered in the Sogno Core deposited on a pelagic plateau is continuous while a hiatus of ~600 kyrs was detected in the lowermost Toarcian in the Gajum Core located on a slope of a structural high. The NJT 5 and NJT 6 Zones of the standard nannofossil zonation for the Mediterranean Province were identified in both the Sogno and Gajum Cores. Our findings allow an implementation of the reference biozonation with the separation of the NJT 6a and NJT 6b Subzones, and age revision of some secondary events. The zonation established for the Lusitanian Basin (Portugal) is only partially reproducible in the Lombardy Basin, confirming nannoplankton paleoprovincialism during the Early Jurassic requiring different zonal schemes in various areas. Nevertheless, we underline that the T-OAE is unambiguously constrained by the FO of C. superbus crassus and the LO of M. jansae at supra-regional scale.

Ryuji Asami, Taketo Matsumori, Ryuichi Shinjo et al.

Abstract The geochemistry of calcifying marine organisms is an excellent proxy for reconstructing paleoceanographic history, but studies of hypercalcified demosponges (sclerosponges) are considerably fewer than those of corals, foraminifers, and bivalves. For this study, we first generated near-annual resolved stable carbon and oxygen isotope (δ13C and δ18O) and element/Ca ratios (Sr/Ca, Ba/Ca, Pb/Ca, U/Ca) time series for 1880–2015 from sclerosponge samples (Acanthochaetetes wellsi) collected at Miyako Island and Okinawa Island in the Ryukyu Islands of southwestern Japan. The δ13C records exhibited a typical variation of anthropogenically derived Suess effects, demonstrating that the rates of decrease of –0.0043‰/year before 1960 and – 0.024‰/year after 1960 in the northwestern subtropical Pacific were respectively similar to and about 1.4 times higher than those of the Caribbean Sea in the tropical Atlantic. Spectral analysis of the δ18O time series revealed significant periodicity of approximately 2, 3, 6.5, 7–10, and 20–30 year/cycle, indicating that sea surface conditions in the southern Ryukyu Islands had been dominated by interannual and decadal variations in temperature and seawater δ18O since the late nineteenth century. The Sr/Ca and U/Ca ratios for the species A. wellsi (high-Mg calcite) might not be a robust proxy for seawater temperatures, unlike Astrosclera willeyana and Ceratoporella nicholsoni sclerosponges (aragonite). An evident increasing Pb/Ca trend after 1950 found in the samples is probably attributable to Pb emissions from industrial activities and atmospheric aerosols in eastern Asian countries. The Ba/Ca variations differ greatly among sampling sites, which might be attributable to the respective local environments. This evidence demonstrates that more high-resolution age determinations and geochemical profilings enable delineation of secular variations in ocean environments on annual and interannual timescales. Results of our study suggest that if sclerosponges living in deeper ocean environments are collected, spatial and vertical oceanographic variations for the last several centuries will be reconstructed along with coral proxy records.

PAOLO MIETTO

Three specimens of Ammonites have been newly found in the Calcari Grigi Fm. (Lower and Middle Liassic). At present the total amount of known Ammonite specimens in the western part of the Venetian Liassic Carbonate Platform is at least of six.  The occurrence of Ammonites ln an unfavourable environment suggests a post—mortem transport from the adjacent Lombardian Basin.

Emilia Le Pera, Consuele Morrone

Abstract The use of mineral interfaces, in sand-sized rock fragments, to infer the influence exerted by mechanical durability on the generation of siliciclastic sediments, has been determined for plutoniclastic sand. Conversely, for volcaniclastic sand, it has received much less attention, and, to our knowledge, this is the first attempt to make use of the volcaniclastic interfacial modal mineralogy of epiclastic sandy fragments, to infer mechanical durability control at a modern beach environment. Volcaniclastic sand was collected along five beaches developed on five islands, of the southern Tyrrhenian Sea (Alicudi, Filicudi, Salina, Panarea and Stromboli) from the Aeolian Archipelago, and one sample was collected near the Stromboli Island volcanic crater. Each sample was sieved and thin sectioned for petrographic analysis. The modal mineralogy of the very coarse, coarse and medium sand fractions was determined by point-counting of the interfacial boundaries discriminating 36 types of interfaces categories, both no-isomineralic and/or no iso-structural (e.g., phenocrystal/glassy groundmass or phenocrystal/microlitic groundmass boundaries) and iso-mineralic interfaces, inside volcanic lithic grains with lathwork and porphyric textures. A total of 47,386 interfacial boundaries have been counted and, the most representative series of interfaces, from the highest to the lowest preservation, can be grouped as: a) ultrastable interfaces, categorized as Pl (Plagioclase)/Glgr (Glassy groundmass) > > Px (Pyroxene)/Glgr > > Ol (Olivine)/Glgr > > Op (Opaque)/Glgr > > Hbl (Hornblende)/Glgr> > Bt (Biotite)/Glgr > > Idd (Iddingsite)/Glgr > > Rt (Rutile) / Glgr; b) stable interfaces, categorized as Pl/Migr (Microlitic groundmass) > > Op/Migr > > Px/Migr > > Ol/Migr; c) moderately stable interfaces, categorized as Op/Px > > Op/Hbl > > Px/P > > Ol/Pl> > Bt/Op; and d) unstable interfaces, categorized as Pl/Pl > > Px/Px > > Ol/Ol > > Op/Op > > Hbl/Hbl > > Bt/Bt. Grains, eroded from the volcanic bedrock, if affected solely by abrasion, developed a rounded and smoothed form, with prevailing no-isostructural interfaces such as Plagioclase/Glassy groundmass, Pyroxene/Glassy groundmass and Olivine/Glassy groundmass interfaces. Grains that during transport suffered fracturing and percussion have a sharp and angular form: these combined transport mechanisms produce mainly volcanic sandy grains with iso-structural interfaces, such as Pl/Pl, Px/Px, Hbl/Hbl, and, to a lesser extent, Bt/Op and Bt/Glgr interfaces.

Can Wang, Houyuan Lu, Houyuan Lu et al.

In the last decade, our understanding of rice domestication has improved by new archaeological findings using advanced analytical techniques such as morphological and morphometric analyses on rice grains, spikelet bases and phytoliths, and ancient DNA analysis on rice remains. Previous studies have considered the size of rice bulliform phytoliths as a proxy for tracking the domestication process. These phytoliths are often abundant and well preserved in sediments, and their shape is under the control of numerous genes, which may shift toward larger sizes by genetic mutation in domestication. Therefore, it has been assumed that the bulliforms of domesticated rice are usually larger than those of wild ones; however, morphometric data supporting this assumption are lacking in the literature, thereby requiring additional evidence to test its veracity. In this study, the vertical and horizonal lengths of bulliform phytoliths were measured in four rice species (domesticated Oryza sativa and wild Oryza rufipogon, Oryza officinalis, and Oryza meyeriana) from different regions of southern China. We found that the bulliform morphometric data of wild and domesticated rice overlapped and that there was no statistically significant difference between them. Therefore, bulliform size could not be used as a diagnostic indicator to distinguish domesticated rice from wild species and is a supporting rather than conclusive proxy for determining the domesticated status of rice in archaeological research. We further found that larger rice bulliform sizes likely occurred at the locations with higher temperature, precipitation, and water levels, indicating hydrothermal environment is an alternative factor influencing the size of rice bulliform phytoliths. For further archaeological use of an increasing size trend of bulliform phytoliths to reveal the process of rice domestication, we present some suggestions for controlling the influence of hydrothermal factors. Even so, the combination of bulliform phytolith size with other established criteria is strongly suggested to provide precise identification of wild and domesticated rice in future research.

Mohammad Taghi Badihagh, Dieter Uhl

Abstract The coal horizons of the Middle Jurassic Hojedk Formation of East-Central Iran are fossiliferous, bearing numerous well-preserved fossil plants, comparable to the Shemshak Group/Formation in the Alborz Mountains in Northern Iran. Here we present two recently discovered fossil taxa from the Middle Jurassic Hojedk Formation of the Tabas Block (Central Iran). Based on their distinct morphologies, impression/compression specimens can be assigned to Phlebopteris dunkeri (Schenk) Schenk (Palaeontographica 23: 157–163, 1875) and P. woodwardii Leckenby (Quarterly Journal of the Geological Society 20 (1–2): 74–82, 1864), belonging to Matoniaceae. This is the first record of these two taxa in Iran. Taxa belonging to Equisetaceae, Marattiaceae, Dipteridaceae, Schizaeaceae, Dicksoniaceae, Caytoniales, Bennettitales, Cycadales and Podozamitaceae were observed as accompanying taxa in the studied section. Ecology comparison of the Hojedk Formation plant fossils with the extant relatives of the fossil plant taxa occurring in these deposits indicates accumulation of the host strata under a moist warm (tropical to subtropical) climate during the Middle Jurassic.

DONALD ALEXANDER BANKIER MACFARLAN

Terebratulides, a minor group in New Zealand and New Caledonian Triassic faunas, become second in prominence only to rhynchonellides in the Jurassic.  In this study, a total of seven genera and twelve species are recognised and eight new species are described. Lobothyris simesi n. sp. is present throughout the Sinemurian to middle Toarcian.  Loboidothyris fordycei n. sp. is common in the late Sinemurian to Pliensbachian of the Hokonui Hills, and a few specimens are recorded from scattered Pliensbachian-Toarcian localities elsewhere. Zeilleria spiculata MacFarlan and Campbell is found in a narrow zone along the Triassic-Jurassic boundary in the Hokonui Hills. Z. terezowae n. sp. is found throughout most of the Early Jurassic, while Z. recessa n. sp. and Z. sacciformis n. sp. have more restricted ranges.  The Sinemurian Aulacothyris stevensi n. sp. is known from the Hokonui Hills, and the coast north of Marokopa. Two further forms of Aulacothyris are present. Linguithyris agerorum Manceñido was described from Port Waikato, and is here recorded from New Caledonia. Tegulithyris? plencnerae n. sp. is known from the Sinemurian to Toarcian of Kawhia, and Rugithyris hasibuani n. sp. from the Awakino area. Lobothyris, Aulacothyris and Zeilleria are cosmopolitan and widely distributed. Loboidothyris is also cosmopolitan, but has a Tethyan aspect. Tegulithyris and Rugithyris are Tethyan. Linguithyris is also known from southern Europe, North Africa and western Asia. The highest Early Jurassic brachiopod faunas occur at or just above the Dactylioceras band near Kawhia, which is correlated with the top of the early Toarcian and lies above the Toarcian event in Western Europe.

R. F. Kay

Maoyan Zhu, L. Babcock, S. Peng