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Re: Origin of feathers (and a sting in the tail)



Norton, Patrick wrote:
>
> This seems reasonable and perfectly consistent with the theory that
> feathers first served the purpose of reducing heat transfer to the body
> by shading. Feathers are an excellent insulating material.  But unless
> Orsen is suggesting that Oviraptor was a flyer, I would not expect to see
> primary feathers--a derived flight character--on its forearm. Modern
> brooding birds protect their eggs from the sun (and the cold) with
> fluffed up body feathers. In any event, at the moment of death this
> particular Oviraptor was probably protecting its eggs against something
> other than the sun.

Some raptors (the extant variety that is) will use out-stretched wings
to shade young chicks from the sun. It can be hard to get a bunch
of squirming youngsters nestled beneath the down feathers. Skeletal
reconstructions of Oviraptors seem to indicate quite long arms
for a creature of that size, something like a dromaeosaur, so either
would have had an excellant base from which to form umbrella-like
feathered shades. As to how likely this is, especially given that
such a structure would probably impinge on a predator's ability
to grasp prey, I couldn't say. Perhaps females grew exceptionally
long arm feathers during the breeding season which moulted off
once the youngsters had left the nest (presuming the females
brooded and not the males).

Unrelated to this thread, but a question that has been bugging me
for a few days, is this: I recently bought an excellant book on
monitor lizards (Rodney Steel's "Living Dragons") which mentioned
the use of monitor lizard tails as defence. This got me thinking.
Would the stiffened and presumably strong tails of dromaeosaurs
have also made good defensive weapons?
-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia

        Dinosaur Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        Australian Dinosaurs:
        http://www.alphalink.com.au/~dannj
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