نتایج جستجو برای: upper triassic diversification

تعداد نتایج: 228621  

2016
Christian Pott Johan van der Burgh

Premise of research. During the ongoing investigation of Upper Triassic–Lower Cretaceous plant macrofossils from Svalbard, Norway, some ginkgoalean leaf fossils were found from Carnian and Aptian deposits of Spitsbergen and Edgeøya that represent new ginkgophyte species. One new species is described asBaiera aquilonia sp. nov., and one ginkgophyte leaf is assigned to Ginkgoites sp. Along with t...

Journal: :Atlantic Geology 2021

Triassic successions of the present-day Arctic contain abundant and diverse assemblages nonmarine palynomorphs that have provided important biostratigraphic information. Dinoflagellate cyst are biostratigraphically useful in marine intervals Upper Triassic. Based on published records, we present a compilation 78 last occurrences (LOs), first (FOs), some abundance events anticipated to correlati...

Journal: :Geochemistry Geophysics Geosystems 2022

Abstract Calcium isotopes (δ 44/40 Ca) are particularly useful in palaeo‐environmental studies due to the key role of carbonate minerals continental weathering and their formation seawater. The calcium isotope ratio can provide hints on past changes fluxes, environmental shifts, ecological factors alternatively diagenesis rocks. investigation Late Triassic record offers a great opportunity eval...

1997
William A. Christiansen Daniel Pace

The relaxation of the Glass-Steagall Act (GSA), the Act which separates commercial and investment banking, is currently under debate. Central to this debate is the potential risk reduction of commercial banks due to diversification. This paper, through a thorough and complete examination of the diversification potential, establishes an upper bound of diversification benefits. The results do sup...

2010
ANDREW B. HECKERT

Six localities in the lower Chinle Group of central New Mexico yield a tetrapod fauna consisting of the diminutive metoposaurid cf. Apachesaurus sp., and indeterminate large metoposaurids (probably Buettneria sp.), the phytosaur Rutiodon sp., indeterminate phytosaurs, the aetosaurs Desmatosuchus sp. and cf Stagonolepis sp., a probable theropod, and other, indeterminate archosaurs. Five of these...

Introduction In economy structure of rural districts in different countries, agriculture is considered as the main source of livelihood. The most important characteristic of this structure is lack of diversification for economic contexts and job opportunities, especially for the increasing number of people in the villages which is almost the result of attitude toward the village and government...

2001
ANDREW B. HECKERT

Ornithischian dinosaur body fossils are extremely rare in Triassic rocks worldwide, and to date the majority of such fossils consist of isolated teeth. Revueltosaurus is the most common Upper Triassic ornithischian dinosaur and is known from Chinle Group strata in New Mexico and Arizona. Historically, all large (>1 cm tall) and many small ornithischian dinosaur teeth from the Chinle have been r...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2017
Jason D Pardo Bryan J Small Adam K Huttenlocker

The origin of the limbless caecilians remains a lasting question in vertebrate evolution. Molecular phylogenies and morphology support that caecilians are the sister taxon of batrachians (frogs and salamanders), from which they diverged no later than the early Permian. Although recent efforts have discovered new, early members of the batrachian lineage, the record of pre-Cretaceous caecilians i...

2017
Max C. Langer Átila A.S. da Rosa Felipe C. Montefeltro

The upper Triassic deposits of the Selous Basin in south Tanzania have not been prospected for fossil tetrapods since the middle of last century, when Gordon M. Stockley collected two rhynchosaur bone fragments from the so called "Tunduru beds". Here we present the results of a field trip conducted in July 2015 to the vicinities of Tunduru and Msamara, Ruvuma Region, Tanzania, in search for sim...

Journal: :Historical Biology 2021

The phylogeny of coelacanths (Devonian-Recent) has been a matter discussion at least since 1940s following the discovery Latimeria chalumnae, and it remains as revisited issue in most recent works. In this contribution, an updated phylogenetic analysis based on new consensual data matrix is presented, merging emendations proposed over past two decades, including completely reviewed character sc...

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