Re: DINOSAUR digest 3384

[Jorge Dichenberg <jorgedich@yahoo.com>]

--- K and T Dykes <ktdykes@arcor.de> wrote:

> <<I agree there were large scale fires in K/T, but
> they cannot explain
> extinction-survival pattern.>>
> 
> A global burst of heat delivered by infrared
> radiation caused by masses of
> debris returning to Earth might, should we restrict
> ourselves to terrestrial
> communities.
> 
> Robertson DS, McKenna MC, Owen BT, Hope S &
> Lillegraven JA, 2004, Survival
> in the first hours of the Cenozoic, Geological
> Society of America Bulletin,
> 116 (5/6), p.760-768.
> http://www.ugcs.caltech.edu/~presto/cenozoic.pdf

I would first ask some meteorologist/astronomer. How
would real atmosphere react? Would falling microscopic
ejecta indeed deliver single heat pulse? I suggest
atmospheric currents would produce uneven fall and
evaporating water would quickly block radiation from
reaching ground. This I don't know. Nor I see
discussed there.

Theory has most of gaps in reasoning of wildfire
theory. I pointed why this could not be true. This
article repeats:

They themselves say that thermal radiation was "except
where Earth surface was shielded by very thick cloud
cover". In the scale of Earth, hundreds of thousands
of km2 are covered by thick clouds every day.  

They accept that sheltering in water would protect
large animal. Even animal submerging with legs
touching bottom would dissipate heat. They try to
defend it surprisingly: "no evidence exists that (...)
non-avain dinosaurs could (...) swim or dive (...)".
It exists. 

They fail to explain selective extinction. They
propose that all Cretaceous mammals were burrowers or
entered water. No evidence of that, especially
together with 
suggestion that no small or young non-avian dinosaurs
behaved similarily.

They cannot explain why birds survived, which mostly
don't shelter - including ratites, numerous
waterbirds, shorebirds etc. 

In fact, most birds react to stress by taking off and
flying - this would burn them immediatley. No mention
of vulnerability of birds to smoke.

They state "that smallest noavian dinosaurs hay have
survied is possible". 

They state that dinosaur eggs and young would survive.
They propose obligatory parental care in all non-avian
dinosaurs - no evidence of that.

Shortly, gaps in reasoning, not present in feeding
ecology and Eden theories.

Jerzy Dyczkowski



                
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