Carbon cycle perturbations and environmental change of the middle permian and Late Triassic Paleo-Antarctic circle.

During the middle Permian through the Triassic, Tasmania moved from paleo-latitudes of 78° to 69°S, wedged between Antarctica and Australia, within the paleo-South polar circle. During this time, significant global carbon cycle disturbances triggered major environmental and climatic changes and mass extinction events globally. The Bicheno-5 core from Eastern Tasmania, Australia, provides the opportunity to examine middle Permian and Upper Triassic sediments from the paleo-Antarctic, using high-resolution organic carbon isotope (δC) chemostratigraphy, pXRF, and sedimentology, combined with new palynological data integrated with the existing radiometric age model.

Parallel evolution of angiosperm-like venation in Peltaspermales: a reinvestigation of Furcula.

Leaf venation is a pivotal trait in the success of vascular plants. Whereas gymnosperms have single or sparsely branched parallel veins, angiosperms developed a hierarchical structure of veins that form a complex reticulum. Its physiological consequences are considered to have enabled angiosperms to dominate terrestrial ecosystems in the Late Cretaceous and Cenozoic.

Nitrogen isotopes reveal independent origins of N-fixing symbiosis in extant cycad lineages.

Cycads are ancient seed plants (gymnosperms) that emerged by the early Permian. Although they were common understory flora and food for dinosaurs in the Mesozoic, their abundance declined markedly in the Cenozoic. Extant cycads persist in restricted populations in tropical and subtropical habitats and, with their conserved morphology, are often called 'living fossils.

New species of Kuqaia from the Lower Jurassic of Sweden indicates a possible water flea (Crustacea: Branchiopoda) affinity.

The enigmatic acid-resistant mesofossil genus Kuqaia is emended, a new species (Kuqaia scanicus) is instituted, and three established species are described from the Lower Jurassic (lower Pliensbachian) of the Kävlinge BH-928 core, in southern Sweden. Kuqaia has a distribution across the middle northern latitudes of Pangaea and is restricted to Lower to lower Middle Jurassic strata. Morphological characters support Kuqaia being the ephippia (resting egg/embryo cases) of Cladocera (Crustacea: Branchiopoda), and a probable early stem-group taxon of the Daphnia lineage.

Traces of Ancient Life in Oceanic Basalt Preserved as Iron-Mineralized Ultrastructures: Implications for Detecting Extraterrestrial Biosignatures.

Benefiting from their adaptability to extreme environments, subsurface microorganisms have been discovered in sedimentary and igneous rock environments on Earth and have been advocated as candidates in the search for extraterrestrial life. In this article, we study iron-mineralized microstructures in calcite-filled veins within basaltic pillows of the late Ladinian Fernazza group (Middle Triassic, 239 Ma) in Italy. These microstructures represent diverse morphologies, including filaments, globules, nodules, and micro-digitate stromatolites, which are similar to extant iron-oxidizing bacterial communities.