نتایج جستجو برای: early triassic

تعداد نتایج: 688914  

2005
G. J. RETALLACK A. H. JAHREN N. D. SHELDON R. CHAKRABARTI C. A. METZGER R. M. H. SMITH

The Permian ended with the largest of known mass extinctions in the history of life. This signal event has been difficult to recognize in Antarctic non-marine rocks, because the boundary with the Triassic is defined by marine fossils at a stratotype section in China. Late Permian leaves (Glossopteris) and roots Vertebraria), and Early Triassic leaves (Dicroidium) and vertebrates (Lystrosaurus) ...

2013
Sterling J. Nesbitt Richard J. Butler David J. Gower

BACKGROUND Archosauria and their closest relatives, the non-archosaurian archosauriforms, diversified in the Early and Middle Triassic, soon after the end-Permian extinction. This diversification is poorly documented in most Lower and Middle Triassic rock sequences because fossils of early groups of archosauriforms are relatively rare compared to those of other amniotes. The early Middle Triass...

2007
ADRIAN P. HUNT SPENCER G. LUCAS JUSTIN A. SPIELMANN ALLAN J LERNER

Coprolites are the least studied and most under-sampled vertebrate trace fossils. They are very common in some Triassic localities. We recognize six new coprolite ichnotaxa: Alococopros triassicus, A. indicus, Saurocopros bucklandi, Liassococopros hawkinsi, Malericopros matleyi and Falcatocopros oxfordensis. The distribution of coprolite ichnotaxa is: Permian Hyronocopros amphipolar and Heterop...

2007

This issue of Palaeogeography Palaeoclimatology Palaeoecology is devoted to papers on the Permian– Triassic boundary crisis and Early Triassic biotic recovery. It is an outgrowth of the Symposium on Early Triassic Chronostratigraphy and Biotic Recovery that was held in Chaohu, China, on May 21st–23rd, 2005 under the auspices of IGCP Project 467 and attended by about 200 Earth scientists with a ...

2006
Daniel J. Lehrmann Jahandar Ramezani Samuel A. Bowring Mark W. Martin Paul Montgomery Paul Enos Jonathan L. Payne Michael J. Orchard

Four volcanic-ash beds bracket the Early-Middle Triassic boundary, as defined by conodont biostratigraphy, in a stratigraphic section in south China. High-precision U-Pb dates of single zircons allow us to place the Early to Middle Triassic (Olenekian-Anisian) boundary at 247.2 Ma. Magnetic-reversal stratigraphy allows global correlation. The new dates constrain the Early Triassic interval char...

Journal: :Proceedings. Biological sciences 2003
Sterling J Nesbitt

The Moenkopi Formation has yielded partial and isolated remains of important archosaurs including rauisuchian skull fragments and isolated poposaur centra and pelvic girdle elements. A recently discovered skeleton referable to Arizonasaurus babbitti shows that most of these archosaurian remains belong to one taxon. Characteristics of the skeleton of Arizonasaurus show that it belongs to a poorl...

2017
Arnaud Brayard L J Krumenacker Joseph P Botting James F Jenks Kevin G Bylund Emmanuel Fara Emmanuelle Vennin Nicolas Olivier Nicolas Goudemand Thomas Saucède Sylvain Charbonnier Carlo Romano Larisa Doguzhaeva Ben Thuy Michael Hautmann Daniel A Stephen Christophe Thomazo Gilles Escarguel

In the wake of the end-Permian mass extinction, the Early Triassic (~251.9 to 247 million years ago) is portrayed as an environmentally unstable interval characterized by several biotic crises and heavily depauperate marine benthic ecosystems. We describe a new fossil assemblage-the Paris Biota-from the earliest Spathian (middle Olenekian, ~250.6 million years ago) of the Bear Lake area, southe...

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 2004
Jonathan L Payne Daniel J Lehrmann Jiayong Wei Michael J Orchard Daniel P Schrag Andrew H Knoll

High-resolution carbon isotope measurements of multiple stratigraphic sections in south China demonstrate that the pronounced carbon isotopic excursion at the Permian-Triassic boundary was not an isolated event but the first in a series of large fluctuations that continued throughout the Early Triassic before ending abruptly early in the Middle Triassic. The unusual behavior of the carbon cycle...

2005
ANDREW B. HECKERT SPENCER G. LUCAS ADRIAN P. HUNT

The Triassic System in Arizona has yielded numerous world-class fossil specimens, including numerous type specimens. The oldest Triassic vertebrates from Arizona are footprints and (largely) temnospondyl bones from the Nonesian (Early Triassic: Spathian) Wupatki Member of the Moenkopi Formation. The Perovkan (early Anisian) faunas of the Holbrook Member of the Moenkopi Formation are exceptional...

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