End-Permian Mass Extinction Reexamined

[Oxytropidoceras]

End-Permian mass extinction was not so massive

By Belinda Smith, Cosmos Magazine

https://cosmosmagazine.com/palaeontology/mass-extinctions-were-not-so-massive-study

 

"US paleontologists states once the dust settled

following the 'great dying' around 250 million

years ago, nearly 20% of species remained – not

4%. Belinda Smith reports."

 

Paleontologist suggests 'great dying' 252 million

years ago wasn't as bad as thought, October 4, 2016

http://phys.org/news/2016-10-paleontologist-great-dying-million-years.html

 

The paper is:

 

Stanley, S. M., 2016, Estimates of the magnitudes

of major marine mass extinctions in earth history.

Proceedings of the National Academy of Sciences,

US, vol. 113 no. 42 E6325-E6334

http://www.pnas.org/content/113/42/E6325

 

Yours,

 

Paul H.

[tmaier]

This change from ~95% mortality to ~80% mortality is found by theoretical calculation, and not by empirical evidence, so it a change in accounting methods, rather than direct evidence.

From the first article:

"Taking Signor-Lipps into account, Stanley calculated the extinction at the end of the Permian, around 250 million years ago, killed off 81% of marine species – fewer than the oft-quoted 96%"

They used a correction factor for Signor-Lipps probability.

It all depends on how you want to calculate this.