Re: Mesozoic birds made insects shrink

[Tim Williams <tijawi@gmail.com>]

David Marjanovic <david.marjanovic@gmx.at> wrote:

> But that's a crab. It doesn't breathe the way insects do. Insects are
> (probably) limited by diffusion and thus by O2 levels. Crabs, and spiders
> for that matter, aren't.


A Science paper from 2003 (Westneat et al.) describes evidence for
tracheal expansion and compression in pterygote insects, analogous to
respiration by vertebrate lungs.  So respiration in insects is not
wholly dependent upon diffusion.



Tom Yazbeck <tyazbeck@comcast.net> wrote:

> Hey, don't diss David Peters. If he didn't insist on clinging to his fringe 
> pet theories, he would be more Greg Paul than Greg Paul.


Ummm... this is a good thing?     ;-)


> And i'm not
> denying that ptero-fuzz isn't well-established, I just was trying to say that 
> some artists go overboard and liberally apply that kind of stuff to their
> illustrations.


The pterosaur integument ( "ptero-fuzz") offered a potential medium
for ornamentation, like the plumage of modern birds. So it would be
surprising if at least some pterosaurs were not brightly colored, and
perhaps even exotic.  So depicting pterosaurs (and contemporary
Mesozoic coelurosaurs) as drab, or even 'naked', would now be
considered unorthodox.







Cheers

Tim