نتایج جستجو برای: upper permian

تعداد نتایج: 207735  

Journal: :Minerals 2022

The Carboniferous–Triassic period was an important stage of global sea–land transformation, with coal formation in the Carboniferous, biological extinction at end Permian, and drought Triassic. MS-1 well Mosuowan High Junggar Basin is deepest drilled Northwestern China. In this paper, we investigate sedimentary environment climate evolution area central during Late Carboniferous–Early Permian b...

2005
Jonathan L. Payne

—A global database of gastropod sizes from the Permian through the Middle Triassic documents trends in gastropod shell size and permits tests of the suggestion that Early Triassic gastropods were everywhere unusually small. Analysis of the database shows that no specimens of unambiguous Early Triassic age larger than 2.6 cm have been reported, in contrast to common 5– 10-cm specimens of both Pe...

2017
Andrew T. Jones Tracy D. Frank Christopher R. Fielding

A suite of ice-rafted dropstones and glendonites throughout the Permian succession of eastern Australia indicates the cold climate associated with the late Paleozoic ice age persisted longest in this part of Gondwana. Paradoxically, these cold climate indicators are preserved in transgressive and highstand facies and formed at mid to high latitudes at a time when paleofloral and sedimentologica...

2000
Evelyn S. Krull Gregory J. Retallack

Stable carbon isotopic analyses of organic carbon (d13C) in individual paleosol profiles from Permian–Triassic sequences of Antarctica reveal systematic isotopic variations with profile depth. These variations are in many cases analogous to those in modern soils, which are functions of redox conditions, soil development, and degree and type of microbial decay. In modern soils, these isotopic de...

Journal: :Proceedings. Biological sciences 2006
Marcello Ruta Peter J Wagner Michael I Coates

Although numerous studies have examined morphological diversification during major radiations of marine taxa, much less attention has been paid to terrestrial radiations. Here, we examine rates of character change over phylogeny and over time for Palaeozoic limbed tetrapods. Palaeozoic tetrapods show significant decreases in rates of character change whether the rate is measured per sampled cla...

2015
Vartika Singh Sundeep K. Pandita Rajni Tewari Peter J van Hengstum Suresh S. K. Pillai Deepa Agnihotri Kamlesh Kumar G. D. Bhat Thierry Smith

Exceptionally well-preserved organic remains of thecamoebians (testate amoebae) were preserved in marine sediments that straddle the greatest extinction event in the Phanerozoic: the Permian-Triassic Boundary. Outcrops from the Late Permian Zewan Formation and the Early Triassic Khunamuh Formation are represented by a complete sedimentary sequence at the Guryul Ravine Section in Kashmir, India,...

2017
T. B. Leonova

The history of the appearance and evolution of the suture, one of the major structural elements of the shells of ammonoids (a subclass of Cephalopoda), is briefly discussed. Its morphology is considered in the Devonian Anarcestida, the first members of which are very similar to the ancestral Bactritoidea, in the Late Devonian Clymeniida, the Devonian–Permian Tornoceratida, the Carboniferous–Per...

2016
Felipe L. Pinheiro Marco A. G. França Marcel B. Lacerda Richard J. Butler Cesar L. Schultz

Birds, dinosaurs, crocodilians, pterosaurs and their close relatives form the highly diverse clade Archosauriformes. Archosauriforms have a deep evolutionary history, originating in the late Permian, prior to the end-Permian mass extinction, and radiating in the Triassic to dominate Mesozoic ecosystems. However, the origins of this clade and its extraordinarily successful body plan remain obscu...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Christian A Sidor Daril A Vilhena Kenneth D Angielczyk Adam K Huttenlocker Sterling J Nesbitt Brandon R Peecook J Sébastien Steyer Roger M H Smith Linda A Tsuji

In addition to their devastating effects on global biodiversity, mass extinctions have had a long-term influence on the history of life by eliminating dominant lineages that suppressed ecological change. Here, we test whether the end-Permian mass extinction (252.3 Ma) affected the distribution of tetrapod faunas within the southern hemisphere and apply quantitative methods to analyze four compo...

2016

Strata exposed near Tabbowa Tank, Tabbowa Basin, western Sri Lanka have yielded the first representatives of the distinctive Permian Glossopteris flora from that country. The assemblage includes gymnosperm foliage attributable to Glossopteris raniganjensis, roots referable to Vertebraria australis, seeds assigned to Samaropsis sp., sphenophyte axes (Paracalamites australis) and foliage (Sphenop...

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