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Re: Microraptor ate birds



Erik Boehm <erikboehm07@yahoo.com> wrote:


> Of course, Microraptor's use of its wings for aerodynamic purposes is not 
> necessarily the same use that lead to to bird wings.


Very true.  However, taxa such as _Microraptor_, _Archaeopteryx_ and
_Jeholornis_ all had large wings composed of asymmetrical feathers -
and none of these forms seem to have been capable of powered flight.
The aerodynamic purposes of their wings might therefore be relevant to
the ancestry of bird flight, even if these individual taxa had very
different ecologies.


> I'm sure the transitional uses for wings in Bats, Pterosaurs, insects, etc 
> were all different.


In the absence of direct fossil evidence, bats are assumed to have
evolved from gliders.  For bats, the shape of the wings in the
stem-chiropteran _Onychonycteris_  points to undulating gliding
(fluttering alternating with 'passive' gliding) being ancestral for
bats.  It is possible that this flight style was ancestral to bird
flight, with sapeornithids representing the transitional phase.  It
all depends on the shape of sapeornithid wings.


> Just because the "pouncing proavis" model fits with what we know of 
> microraptor, doesn't mean it fits for the ancestors of Microraptor's
> bird prey(or scavenged meals?)


Again, very true.  The Pouncing Proavis model actually proposed
_Caudipteryx_ as exemplifying the incipient flight behavior - even if
_Caudipteryx_ itself occurred too late in time.


> - I still want to know if "wings" are ancestral to dromeosaurs- are 
> microaptors wings a case of parallel evolution, or were wings present
> at the split from birds and dromeosaurs?
> Its a particularly attractive idea to me for some reason (ie: I want it to be 
> true, I admit my bias)


Wings appear to be ancestral to the bird+deinonychosaur clade (Paraves).





Cheers

Tim