نتایج جستجو برای: mesozoic refractory sand

تعداد نتایج: 88414  

2013
Ke CHEN Charles GUMIAUX Romain AUGIER Yan CHEN Qingchen WANG Shengli WANG

The Tian Shan range offers a natural laboratory to study orogenic processes. Most of the previous studies focused on either the Paleozoic evolution of the range or its Cenozoic intracontinental evolution linked with the India-Asia collision. In this study, detailed field investigations on the relationship between sedimentary cover and basement constrain the Mesozoic evolution of the northern Ti...

2015
Min Wang Xiaoting Zheng Jingmai K. O'Connor Graeme T. Lloyd Xiaoli Wang Yan Wang Xiaomei Zhang Zhonghe Zhou

Ornithuromorpha is the most inclusive clade containing extant birds but not the Mesozoic Enantiornithes. The early evolutionary history of this avian clade has been advanced with recent discoveries from Cretaceous deposits, indicating that Ornithuromorpha and Enantiornithes are the two major avian groups in Mesozoic. Here we report on a new ornithuromorph bird, Archaeornithura meemannae gen. et...

Journal: :Molecular phylogenetics and evolution 2000
B M Wiegmann C Mitter J C Regier T P Friedlander D M Wagner E S Nielsen

Compared to the number of genes available for study of both younger and older divergences, few genes have yet been identified that can strongly resolve phylogenetic splits of Mesozoic age ( approximately 65-250 mya). Thus, reconstruction of Mesozoic-age phylogenies, exemplified by basal divergences within the major orders of holometabolous insects, is likely to be especially dependent on combin...

Journal: :Current Biology 2015
Roger A. Close Matt Friedman Graeme T. Lloyd Roger B.J. Benson

A series of spectacular discoveries have transformed our understanding of Mesozoic mammals in recent years. These finds reveal hitherto-unsuspected ecomorphological diversity that suggests that mammals experienced a major adaptive radiation during the Middle to Late Jurassic. Patterns of mammalian macroevolution must be reinterpreted in light of these new discoveries, but only taxonomic diversi...

2015
Jostein Starrfelt Lee Hsiang Liow

14 The fossil record is a rich source of information about biological diversity in the past. However, the fossil 15 record is not only incomplete but has inherent biases due to geological, physical, chemical and biological 16 factors. Our knowledge of past life is also biased because of differences in academic and amateur interests 17 and sampling efforts. As a result, not all individuals or sp...

2017
Ola Fredin Giulio Viola Horst Zwingmann Ronald Sørlie Marco Brönner Jan-Erik Lie Else Margrethe Grandal Axel Müller Annina Margreth Christoph Vogt Jochen Knies

In-situ weathered bedrock, saprolite, is locally found in Scandinavia, where it is commonly thought to represent pre-Pleistocene weathering possibly associated with landscape formation. The age of weathering, however, remains loosely constrained, which has an impact on existing geological and landscape evolution models and morphotectonic correlations. Here we provide new geochronological eviden...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2016
Jostein Starrfelt Lee Hsiang Liow

The fossil record is a rich source of information about biological diversity in the past. However, the fossil record is not only incomplete but has also inherent biases due to geological, physical, chemical and biological factors. Our knowledge of past life is also biased because of differences in academic and amateur interests and sampling efforts. As a result, not all individuals or species t...

2014
Zhengshi Wang Shan Ren Ning Huang

Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the...

2015
Tze-Kei Tse Michael Pittman Mee-mann Chang

We describe a Mesozoic fish Paralycoptera sp. (Teleostei: Osteoglossoidei), on the basis of a postcranial skeleton collected from the volcaniclastic mudstones of the Lai Chi Chong Formation of Hong Kong, China. The new finding-representing the city's first Mesozoic fish-extends the geographical distribution of Paralycoptera from eastern mainland China into Hong Kong, demonstrating a wider distr...

Journal: :Systematic biology 2012
Martín D Ezcurra Federico L Agnolín

Late Mesozoic palaeobiogeography has been characterized by a distinction between the northern territories of Laurasia and the southern landmasses of Gondwana. The repeated discovery of Gondwanan lineages in Laurasia has led to the proposal of alternative scenarios to explain these anomalous occurrences. A new biogeographical model for late Mesozoic terrestrial ecosystems is here proposed in whi...

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