9 research outputs found

    Changes to the Fossil Record of Insects through Fifteen Years of Discovery

    Get PDF
    The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well

    The Impact of Payment Context on the Use of Mobile Payment Systems.

    No full text
    The development of the Internet and the arrival of e-commerce fostered digitalization in the payment processes by providing a variety of electronic payment options including payment cards (credit and debit), digital and mobile wallets, electronic cash, contactless payment methods etc. Mobile payment services with their increasing popularity are presently under the phase of transition, heading towards a promising future of tentative possibilities along with the innovation in technology. At this point of the development, we look at the current state of the payment services market from a literature review perspective. We review prior literature on technology adoption and analyze the various factors that impact choice of payment method, specifically mobile payment. To facilitate the analysis of literature, we propose a framework based on The Unified Theory of Acceptance and Use of Technology 2 (UTAUT2) developed by Venkatesh, Thong and Xu in 2012. Notably, we have expanded the model by introducing the impact of contextual factors such as product involvement of item purchased, time pressure and whether the purchase happens online or offline on the choice of the payment method

    Fossil insects of the middle and upper Permian of European Russia

    No full text

    EARLY HISTORY OF ARTHROPOD AND VASCULAR PLANT ASSOCIATIONS

    No full text
    corecore