Selective extinction

[Luis Oscar Romero <legolas@abaconet.com.ar>]

Rob Meyerson wrote:

>When we look at the major theories for the late-K mass extinction, all
of=
>them point to a heavily restrictive environment.  To use the=
>haymaker-impact scenario as an example, the resulting disruption of
the=
>land food chain will mean that food will be in short supply.  Because
of=
>this, animals that can get by on small amounts of food will survive,
which=
>would include most ectotherms and smaller endotherms.  Under this=
>hypothesis, birds survived because they enhabited the "small endotherm"
end=
>of the scale, while the pterosaurs were in the "large endotherm" end.
>
>So, IMHO, birds survived simply because they were small.<

Just a layman's thoughts:

Flight was a definite advantage, not only in getting out of harm's way,
but also in searching for whatever food was available, and maybe their
very specialized feathers provide a better insulation against the hard
environmental conditions.
Are there any stats on how animals fared discriminated by skin coverings
(i.e.: naked, scales, fur, feathers, exoskeletons, etc.) ?

Of course, water (unless part of the problem due to changes in
temperature, contamination, etc.) will provide some sort of protection,
so it seem logical to me that deeper dwelling animals will stand a
better change of survival than those who live or feed near the surface.

Oscar