[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Phil: Meteor May Not Have Destroyed Dinosaurs Afterall?
- To: firstname.lastname@example.org
- Subject: Re: Phil: Meteor May Not Have Destroyed Dinosaurs Afterall?
- From: "E.P. Grondine" <email@example.com>
- Date: Thu, 7 Oct 1999 11:47:04 -0700 (PDT)
- Old-X-Envelope-To: <firstname.lastname@example.org>
- Resent-Date: Thu, 7 Oct 1999 14:47:25 -0400 (EDT)
- Resent-From: email@example.com
- Resent-Message-ID: <gagKLD.A.nZD.HpO_3@mu.pair.com>
- Resent-Sender: firstname.lastname@example.org
Hello Phil -
--- Phil Bagnall <email@example.com> wrote:
> The extinction pattern of plant life is confusing.
> Kirk Johnson, of the Denver Museum of Natural
> History, has undertaken a study of fossilized
> plants which shows that 85% vanished at the end of
> the Cretaceous. However, pollen shows an extinction
> rate of just 30%. Denver USGS researcher Doug
> Nichols has found that palms and screw pines, which
> are easily killed off by frost, survived across
> the K-T boundary as far north as Saskatchewan,
> indicating that any post-impact cold/dark period
> lasted only a few months at most. In New Mexico the
> extinctions occur exactly at the K-T boundary
> without showing the gradation from north to south
> expected from progressive cooling. Western North
> America shows the highest extinction rates while New
> Zealand suffered far fewer losses.
At this time most of the Earth's plants reproduced by
spore, not seed. The Earth's surface was set on fire,
so the spores did not survive in most places. There
was also an acid rain and climatic collapse, but seeds
could survive flames, acid rain, and climatic collapse
lying below ground in a dormant state.
I don't know how nickel affects spores.
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com
Archives located at:
For help, FAQ's and sub. info. visit: