نتایج جستجو برای: triassic boundary

تعداد نتایج: 162654  

2005
Charles Marshall

In a groundbreaking paper, Ward et al. (1) provided both the stratigraphic context and a quantitative description of the terrestrial vertebrate fossil record across the PermianTriassic (P-T) boundary from the Karoo basin in South Africa. They drew three primary conclusions: (i) that there was an accelerated gradual decline in diversity prior to the P-T boundary (in the Dicynodon Zone); (ii) tha...

2012
Roger B. J. Benson Mark Evans Patrick S. Druckenmiller

Invasion of the open ocean by tetrapods represents a major evolutionary transition that occurred independently in cetaceans, mosasauroids, chelonioids (sea turtles), ichthyosaurs and plesiosaurs. Plesiosaurian reptiles invaded pelagic ocean environments immediately following the Late Triassic extinctions. This diversification is recorded by three intensively-sampled European fossil faunas, span...

Journal: :Biology letters 2015
Guang-Hui Xu Li-Jun Zhao Chen-Chen Shen

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 ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2016
Claudia A Marsicano Randall B Irmis Adriana C Mancuso Roland Mundil Farid Chemale

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...

2017
Tomasz Szczygielski

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...

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 ...

2014
Jun Liu Shi-xue Hu Olivier Rieppel Da-yong Jiang Michael J. Benton Neil P. Kelley Jonathan C. Aitchison Chang-yong Zhou Wen Wen Jin-yuan Huang Tao Xie Tao Lv

The presence of gigantic apex predators in the eastern Panthalassic and western Tethyan oceans suggests that complex ecosystems in the sea had become re-established in these regions at least by the early Middle Triassic, after the Permian-Triassic mass extinction (PTME). However, it is not clear whether oceanic ecosystem recovery from the PTME was globally synchronous because of the apparent la...

2007
ADRIAN P. HUNT SPENCER G. LUCAS

Triassic tetrapod tracks have long been studied, including classic ichnofaunas such as those of the lower Newark Supergroup of eastern North America and the Bundsandstein of central Europe. They are known from all seven continents and encompass five archetypal vertebrate ichnofacies for nonmarine environments (Chelichnus, Grallator, Batrachichnus, Brontopodus, Characichnos), all of which are pr...

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