نتایج جستجو برای: late cretaceous

تعداد نتایج: 201920  

N. Naimi Ghassabiyan

The study area is situated in the Middle part of the Tabas Block. It contains outcrops of rocks that formed along longitudinal faults in Early Cimmerian orogenic phase. The basin subsided along these faults from the Late Triassic to Early Cretaceous, which include two sedimentary cycles. A sedimentary cycle, related to Upper Triassic to Bajocian is known as Shemshak group. Another sedimentary c...

2018
Nicholas R Longrich David M Martill Brian Andres

Pterosaurs were the first vertebrates to evolve powered flight and the largest animals to ever take wing. The pterosaurs persisted for over 150 million years before disappearing at the end of the Cretaceous, but the patterns of and processes driving their extinction remain unclear. Only a single family, Azhdarchidae, is definitively known from the late Maastrichtian, suggesting a gradual declin...

Journal: :Proceedings. Biological sciences 2014
Sebastián Apesteguía Raúl O Gómez Guillermo W Rougier

Rhynchocephalian lepidosaurs, though once widespread worldwide, are represented today only by the tuatara (Sphenodon) of New Zealand. After their apparent early Cretaceous extinction in Laurasia, they survived in southern continents. In South America, they are represented by different lineages of Late Cretaceous eupropalinal forms until their disappearance by the Cretaceous/Palaeogene (K/Pg) bo...

Journal: :Anais da Academia Brasileira de Ciencias 2011
Haruo Saegusa Yukimitsu Tomida

Sauropod teeth from six localities in Japan were reexamined. Basal titanosauriforms were present in Japan during the Early Cretaceous before Aptian, and there is the possibility that the Brachiosauridae may have been included. Basal titanosauriforms with peg-like teeth were present during the "mid" Cretaceous, while the Titanosauria with peg-like teeth was present during the middle of Late Cret...

2010
Emmanuelle Puceat Christophe Lecuyer Yannick Donnadieu Philippe Naveau Gilles Ramstein Brian T. Huber Juergen Kriwet

The oxygen isotope composition of fossil fish teeth, a paleoupper ocean temperature proxy exceptionally resistant to diagenetic alteration, provides new insight on the evolution of the lowto middlelatitude thermal gradient between the middle Cretaceous climatic optimum and the cooler latest Cretaceous period. The new middle Cretaceous low to middle latitude thermal gradient agrees with that pre...

2014
Thomas E. Williamson Stephen L. Brusatte

Studying the evolution and biogeographic distribution of dinosaurs during the latest Cretaceous is critical for better understanding the end-Cretaceous extinction event that killed off all non-avian dinosaurs. Western North America contains among the best records of Late Cretaceous terrestrial vertebrates in the world, but is biased against small-bodied dinosaurs. Isolated teeth are the primary...

2011
Hussam Zaher Diego Pol Alberto B. Carvalho Paulo M. Nascimento Claudio Riccomini Peter Larson Rubén Juarez-Valieri Ricardo Pires-Domingues Nelson Jorge da Silva Diógenes de Almeida Campos

Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-...

2014
L. Colli I. Stotz H.-P. Bunge M. Smethurst S. Clark G. Iaffaldano A. Tassara F. Guillocheau

The South Atlantic region displays (1) a topographic gradient across the basin, with Africa elevated relative to South America, (2) a bimodal spreading history with fast spreading rates in Late Cretaceous and Eo-Oligocene, and (3) episodic regional uplift events in the adjacent continents concentrated in Late Cretaceous and Oligocene. Here we show that these observations can be linked by dynami...

2011
Eduardo Puértolas José I. Canudo Penélope Cruzado-Caballero

BACKGROUND The earliest crocodylians are known primarily from the Late Cretaceous of North America and Europe. The representatives of Gavialoidea and Alligatoroidea are known in the Late Cretaceous of both continents, yet the biogeographic origins of Crocodyloidea are poorly understood. Up to now, only one representative of this clade has been known from the Late Cretaceous, the basal crocodylo...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Nicholas R Longrich Tim Tokaryk Daniel J Field

The effect of the Cretaceous-Paleogene (K-Pg) (formerly Cretaceous-Tertiary, K-T) mass extinction on avian evolution is debated, primarily because of the poor fossil record of Late Cretaceous birds. In particular, it remains unclear whether archaic birds became extinct gradually over the course of the Cretaceous or whether they remained diverse up to the end of the Cretaceous and perished in th...

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