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RE: The Men Who Stare At New Papers



> In the evolution of flight in theropods, the key word is
> "exaptation".  Many flight-related features that we see
> in birds likely evolved originally for other purposes, such
> as the furcula ("wishbone"), long forelimbs, pneumatic
> bones, enlarged breastbone (sternum), and of course
> feathers.  All these features came to be incorporated
> into the avian flight apparatus (probably in a stepwise
> fashion), but they probably didn't begin that way.
> 

I thought flight (gliding or powered) came before the enlarged breastbone, and 
that primitive birds (which clearly could at least glide) didn't have them?

>  For example,
> are these features perhaps correlated with reinforcing
> feather attachment?  It was once assumed that the
> presence of quill nodes along the ulna was an exclusively
> flight-related character - until they turned up in
> _Velociraptor_.

Unless, of course, Velociraptor had flying/gliding ancestors / was secondarily 
flightless, which appears likely.