Re: Pelecanimimus and Sinosauropteryx

[Thom Quinn <swo@execpc.com>]

First, I am going to say the most parts of an animals body are being
acting on by many forces at once, so breaking them down is hard to do. 

Feather today are used mainly for thermoregulation, locomotion, and
communication today.

It is likely that all three of these forces were involved in feather
evolution---and still are! 

IT is obvious the very first feather would have not been much use for
locomotion...half a feather or ones with the wrong shapes would not do
much for flying or swimming or even running.

The significance of thermoregulation in feather evolution all depends on
when these animals became "warm-blooded"...was it after or before
feather evolution...

It is very possible that the initial thrust into feather evolution could
have been communication. Birds are very susceptible to super-stimulus
objects (i.e. birds will sit on large white soccer balls instead of eggs
if given a choice) and I think we can all see the possible use of
enlarged scales...I will not be so bold to suggest what these would be
used for (perhaps sexual, perhaps defensive, perhaps for species
identification to prevent hybridization). 

The first "function" feathers could have been nothing more than
modified, elongated scales.

Without better fossils of feathers and protobird, it will be hard to
sort it all out!