* Astronomy

Findings Rock Long-Held Assumptions about Ancient Mass Extinction

New evidence gathered from the Karoo Basin in South Africa sheds light on a catastrophic extinction event that occurred more than 250 million years ago and wiped out more than 90 percent of life in Earth's oceans and about 70 percent of animal species on land. The new evidence derives from a key volcanic ash deposit that the team discovered in rock layers, or strata, that were reported to chronicle the mass extinction. By dating the volcanic ash-bearing deposit, researchers concluded that two phases of this extinction - one on land, the other in the oceans - occurred at least 1 million years apart, as opposed to roughly at the same time, as the geoscience community has assumed for decades.
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MIT researchers find that the end-Permian extinction happened in 60,000 years - much faster than earlier estimates.

Multiple theories have aimed to explain the cause of what's now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.
Now researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years - practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.
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Oddest couple share 250mil year old burrow

Scientists from South Africa, Australia and France have discovered a world first association while scanning a 250 million year old fossilised burrow from the Karoo Basin of South Africa.
The burrow revealed two unrelated vertebrate animals nestled together and fossilised after being trapped by a flash flood event. Facing harsh climatic conditions subsequent to the Permo-Triassic (P-T) mass extinction, the amphibian Broomistega and the mammal forerunner Thrinaxodon cohabited in a burrow.
Scanning shows that the amphibian, which was suffering from broken ribs, crawled into a sleeping mammals shelter for protection. This research suggests that short periods of dormancy, called aestivation, in addition to burrowing behaviour, may have been a crucial adaptation that allowed mammal ancestors to survive the P-T extinction.
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China Deposits Point To Cause Of Earth's Deadliest Extinction

University of Cincinnati professor Thomas J. Algeo, working with a team of Chinese scientists, has established a tight link between repeated episodes of volcanic activity and environmental degradation leading up to the deadliest extinction in Earth's history.
In a paper published in the November 2012 issue of the journal Geology, Algeo and colleagues from the China University of Geosciences track patterns of carbon isotope ratios associated with volcanic ash layers preserved in southern China rock layers. In particular, the team looked at two rock successions preserving finely layered marine deposits that record volcanic activity from before the end of the Permian period (252 million years ago) through the early part of the next geologic period, the Triassic. These successions contain layers recording events during the crisis that resulted in the extinction of some 90 percent of marine species on Earth.
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