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Re: Copeing with mammals



On Sun, 21 Nov 2004, David Marjanovic wrote:

> >> Nothing dead or alive can compete with a
> >> pteranodontid or azhdarchid.
> >
> > Albatrosses.
>
> 1. Too small. Won't eat food of the same size class.
> 2. The only evidence for albatrosses before the late Oligocene is a
> Maastrichtian furcula (!!!) from the arguably wrong hemisphere.

Pterosaurs clearly had issues.  As a clade, their extinction was long and
slow.  This argues against a long series of accidental extinction events.
It argues _for_ some kind of deficit relative to other clades.  I have
proposed a reasonable problem--that juveniles (or adults, for that
matter) were not as agile in the air as neornithines, and were therefore
more susceptible to predation/general harrassment.  Competition is seldom
a head-to-head race to see who can eat the resources the fastest.  It is
often an indirect cause that leads to inability to compete.  So,
I'm not talking about albatrossess being direct competitors to pteros,
only that they can survive in a competitive environment that pteros could
not.  I don't _know_ this.  It is just what I think.

> > It is conceivable that their juveniles are better than
> > pteros at avoiding long range aerial predators (e.g., frigate birds?).
> > If so, they are better competitors.
>
> Not if big pterosaurs, like neornithine birds, grow first and learn to fly
> later.
>
> I think you are grasping for straws in this case.

You seem to be arguing that flying ability doesn't enhance
competitiveness; or that even if neornithines _were_ better fliers they
somehow gave the pteros a free pass.
But what are you arguing?  That each pterosaur species extinction was
unrelated, caused by a separate environmental whim?