منابع مشابه
The end-Permian extinction
The end Permian extinction was the greatest mass extinction of the Phanerozoic Era. It impacted marine and terrestrial plants and animals. Although the rate of the extinction has been controversial in the past, recent evidence suggests that the extinction progressed in two pulses approximately 5-12 million years apart. The second pulse of the extinction is marked by a sharp temperature spike an...
متن کاملEthnobotanical Studies in Lahul and Spiti, Himachal Pradesh
The paper presents 41 folklore claims collected from the tribes Gaddi, Swangla, Bhot and other local inhabitants residing in the district of Lahul and spiti in Himachal Pradesh. 41 taxa belonging to 39 genera and 24 families have been described. Botanical name of the plant, family, local name, place of collection, altitude, collection number and mode of administration have been given. Uses of m...
متن کاملThe Permian bacterium that isn't.
There is growing evidence for the presence of viable microorganisms in geological salt formations that are millions of years old. It is still not known, however, whether these bacteria are dormant organisms that are themselves millions of years old or whether the salt crystals merely provide a habitat in which contemporary microorganisms can grow, perhaps interspersed with relatively short peri...
متن کاملPermian ancestors of Hymenoptera and Raphidioptera
The origin of Hymenoptera remains controversial. Currently accepted hypotheses consider Hymenoptera as the first side branch of Holometabola or sister-group to Mecopteroidea. In contrast, fossils confirm the idea of Martynov that Hymenoptera are related to Megaloptera and Raphidioptera. Hymenoptera have descended along with Raphidioptera from the earliest Megaloptera, the Permian Parasialidae. ...
متن کاملPetrophysical Characterization of Permian Shallow-Water Dolostone
The complex interplay between depositional facies and diagenesis in dolostones presents numerous challenges for calculating petrophysical properties from wireline logs. Complex pore geometries and mineralogies control rock petrophysical properties, and equations for calculating porosities and saturations must therefore be tailored to specific pore geometry-mineralogy combinations. The complex m...
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ژورنال
عنوان ژورنال: Nature
سال: 1989
ISSN: 0028-0836,1476-4687
DOI: 10.1038/341379b0