نتایج جستجو برای: early permian

تعداد نتایج: 688457  

2016
Da-Yong Jiang Ryosuke Motani Jian-Dong Huang Andrea Tintori Yuan-Chao Hu Olivier Rieppel Nicholas C. Fraser Cheng Ji Neil P. Kelley Wan-Lu Fu Rong Zhang

Contrary to the fast radiation of most metazoans after the end-Permian mass extinction, it is believed that early marine reptiles evolved slowly during the same time interval. However, emerging discoveries of Early Triassic marine reptiles are questioning this traditional view. Here we present an aberrant basal ichthyosauriform with a hitherto unknown body design that suggests a fast radiation ...

2017
Tomasz Szczygielski Dawid Surmik Agnieszka Kapuścińska Bruce M Rothschild

We report the first occurrence of congenital scoliosis in an early Permian aquatic parareptile, Stereosternum tumidum from Paraná state, Brazil. The spine malformation is caused by a congenital hemivertebra. These observations give insight into the biomechanical aspects of underwater locomotion in an axial skeleton-compromised aquatic amniote. This is the oldest record of a hemivertebra in an a...

2004
NEIL J. TABOR CRAYTON J. YAPP ISABEL P. MONTAÑEZ

Pedogenic goethites in each of two Early Permian paleosols appear to record mixing of two isotopically distinct CO2 components—atmospheric CO2 and CO2 from in situ oxidation of organic matter. The C values measured for the Fe(CO3)OH component in solid solution in these Permian goethites are 13.5‰ for the Lower Leonardian ( 283 Ma BP) paleosol (MCGoeth) and 13.9‰ for the Upper Leonardian ( 270 M...

2004
E. S. KRULL

Carbon isotopic studies from marine organic matter of the Permian-Triassic Maitai Group, New Zealand, reveal a significant 5Corg shift toward more negative values within the Little Ben Sandstone Formation. These isotopic data chemostratigraphically define the previously debated position of the Permian-Triassic boundary in the Maitai Group. The Permian-Triassic record of the Maitai Group is also...

2015
Ryosuke Motani Xiao-hong Chen Da-yong Jiang Long Cheng Andrea Tintori Olivier Rieppel

Traditional wisdom holds that biotic recovery from the end-Permian extinction was slow and gradual, and was not complete until the Middle Triassic. Here, we report that the evolution of marine predator feeding guilds, and their trophic structure, proceeded faster. Marine reptile lineages with unique feeding adaptations emerged during the Early Triassic (about 248 million years ago), including t...

Journal: :Science 2005
Peter D Ward Jennifer Botha Roger Buick Michiel O De Kock Douglas H Erwin Geoffrey H Garrison Joseph L Kirschvink Roger Smith

The Karoo basin of South Africa exposes a succession of Upper Permian to Lower Triassic terrestrial strata containing abundant terrestrial vertebrate fossils. Paleomagnetic/magnetostratigraphic and carbon-isotope data allow sections to be correlated across the basin. With this stratigraphy, the vertebrate fossil data show a gradual extinction in the Upper Permian punctuated by an enhanced extin...

2010
Rose Prevec Robert A. Gastaldo Johann Neveling Samuel B. Reid Cindy V. Looy

In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: An autochthonous glossopterid flora with latest Permian palynomorphs and its depositional setting in the Dicynodon Assemblag...

2006
Gregory J. Retallack Tara Greaver

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...

2016
M O Clarkson R A Wood S W Poulton S Richoz R J Newton S A Kasemann F Bowyer L Krystyn

The end-Permian mass extinction, ∼252 million years ago, is notable for a complex recovery period of ∼5 Myr. Widespread euxinic (anoxic and sulfidic) oceanic conditions have been proposed as both extinction mechanism and explanation for the protracted recovery period, yet the vertical distribution of anoxia in the water column and its temporal dynamics through this time period are poorly constr...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2017
Georg Feulner

The bulk of Earth's coal deposits used as fossil fuel today was formed from plant debris during the late Carboniferous and early Permian periods. The high burial rate of organic carbon correlates with a significant drawdown of atmospheric carbon dioxide (CO2) at that time. A recent analysis of a high-resolution record reveals large orbitally driven variations in atmospheric CO2 concentration be...

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