نتایج جستجو برای: triassic
تعداد نتایج: 3848 فیلتر نتایج به سال:
An ophiuroid assemblage from Rhaetian dark shales in a subrosion pipe (or sinkhole) penetrating middle Triassic (Muschelkalk) strata, and, outside the subrosion pipe, disconcordantly overlying middle Triassic strata, east of Winterswijk, the Netherlands, is described, discussed and assessed taxonomically. The material consists of nearly intact and articulated as well as wholly disintegrated ske...
Crocodylomorphs originated in the Late Triassic and were the only crocodile-line archosaurs to survive the end-Triassic extinction. Recent phylogenetic analyses suggest that the closest relatives of these generally gracile, small-bodied taxa were a group of robust, large-bodied predators known as rauisuchids implying a problematic morphological gap between early crocodylomorphs and their closes...
The Newark-APTS established a high-resolution framework for the Late Triassic and Early Jurassic. Palaeomagnetic polarity correlations to marine sections show that stage-level correlations of continental sequences were off by as much as 10 million years. New U–Pb ages show the new correlations and the Newark basin astrochronology to be accurate. Correlation of Newark-APTS to the Chinle Formatio...
Gliding adaptations in thoracopterid flying fishes represent a remarkable case of convergent evolution of overwater gliding strategy with modern exocoetid flying fishes, but the evolutionary origin of this strategy was poorly known in the thoracopterids because of lack of transitional forms. Until recently, all thoracopterids, from the Late Triassic of Austria and Italy and the Middle Triassic ...
Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age contro...
Introduction: The age of the ~23 km in diameter Rochechouart impact structure, France, hosted by Precambrian to Paleozoic (Variscan) crystalline rocks of the northwestern French Massif Central, has long time been a matter of debate. Previous studies, including K-Ar, Rb-Sr, apatite and glass fission track, as well as paleomagnetic dating (see [1] for summary of ages), resulted in a broad (Middle...
All derived turtles are characterized by one of the strongest reductions of the dorsal elements among Amniota, and have only 10 dorsal and eight cervical vertebrae. I demonstrate that the Late Triassic turtles, which represent successive stages of the shell evolution, indicate that the shift of the boundary between the cervical and dorsal sections of the vertebral column occurred over the cours...
Introduction: Cosmic spherules are subspherical to spherical particles of <1 mm diameter which are produced by melting of interplanetary dust and large objects during atmospheric entry. Although cosmic spherules are known principally from the ice sheets of polar regions and Cenozoic deep-sea sediments [1-3], a few spherules older than Mesozoic were recovered from the sedimentary rocks of pelagi...
Coalsack Bluff was the first discovery site in Antarctica for the latest Permian to earliest Triassic reptile Lystrosaurus. This together with discovery of Permian Glossopteris leaves during the heroic age of Antarctic exploration, indicated not only that Antarctica was part of Gondwanaland, but also that Antarctic rocks recorded faunas from the greatest of all mass extinctions at the Permian–T...
Article history: The Permian–Triassic Boun Received 16 August 2008 Received in revised form 3 February 2009 Accepted 11 February 2009 Available online 19 March 2009 Editor: M.L. Delaney
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید