Re: Meteroic Evidence For Permian-Triassic Extinction

[Jeff Hecht <jeff@jeffhecht.com>]

I believe the canonical 90-95% figure comes from the work of David 
Raup and Jack Sepkoski on marine invertebrates, which are extremely 
well-represented in the fossil record. That data must be about 15 
years old, and has been quoted so often it's become part of the folk 
wisdom.

I don't know what other analyses have been done more recently, or if 
anyone has attempted to average the effects over all species at the 
time. It's quite possible that marine invertebrates suffered 
disproportionately from the marine anoxia and sea-level change at the 
time. -- Jeff Hecht

At 2:15 PM +1100 11/22/03, Phil Hore wrote:
> I'm boning up (exscuse the pun) on the start of the Triassic for a 
> peice I'm writting and what I find odd is I'm finding no 'extinction 
> of 95%' of all life happening. There is certainly a lot going on and 
> many species are disapearing, but 95% just doesn't seem to be the 
> figure I'm seeing...maybe more 65-70 %...to be fair I've only just 
> started my research so I have a lot more to look through. I just 
> find it odd and am thinking that if there was an impact at the end 
> of the permian, it was a lot more localised then the global killer 
> of the KT impact.
>
>
>
>
> Phil Hore
>
> National Dinosaur Museum
>
> Canberra, Australia
>
> ph (02) 62302655

--
Jeff Hecht, science & technology writer
jeff@jeffhecht.com; http://www.jeffhecht.com
Boston Correspondent: New Scientist magazine
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