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Michael Lovejoy wrote:

> The main thing all (more or less!) theropods and
> birds have in common is the
> furcula. 
> So, try to imagine a Coelophysis, running after
> prey. Flat out, short on
> breath and overheating, it flaps it's arms, so
> getting mechanical help with
> breathing and heat loss, and catches it's dinner!

Let's extend this scenario to other "ceratosaurs" like
_Carnotaurus_. Would flapping those itty bitty nubbins
help it recooperate during or after chasing a small
ornithopod or young sauropod? Heh. Nice image.   

> Thus we have a flight stroke, used not just once for
> predation, but as a
> regular part of high speed running.

I'm curious whether it would truly help in
respiration. While it might help ventilate the lungs
and air sacs, the oxygen consumption by those brachial
muscles might do more harm than good. You are taking
fuel that could be used to power the legs and feeding
it to the arms. Do ostriches do it? Not that I'm aware
of. Flying birds do, but they aren't utilizing *both*
sets of appendages like your _Coelophysis_ is.  

> Jump forward in the Mesozoic, to a time when a small
> Microraptor/Sinornithosaurus-type creature is
> clambering about in the trees.
> It's arms have lengthened for climbing, and they are
> covered with feathers
> (brooding/ insulation/ display/ basal to
> Archosauria/ whatever). 

Wouldn't the evolution of long feathers on the arm
make it difficult to flap during a chase? 

> Okay, I know it makes a lot of assumptions (air sacs
> in basal theropods, for
> one.) Feel free to criticise in the harshest manner
> possible.....
> Regards,
> Michael Lovejoy

I remain unconvinced, but it was a good thought.

W. Rowley 

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