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RE: Evidence For a Feathered Velociraptor...



Even leaving aside phylogenetic bracketing, there is more than one way of
approaching the question of flight behavior in fossil taxa.  The following
criteria may be those most commonly used: 

Does the animal sport an ample suite of features that would appear to
optimize it for aerial locomotion?  Are there no features or aspects of the
animal that would preclude aerial locomotion?     

On the other side of the coin there is the following question:

Is its body plan most simply explained in terms of flight adaptation?

I bring this up because I presume that this latter reasoning weighs into the
apparently universal assumption that pterosaurs were flying animals.  In
other words, because pterosaurs don't appear to be optimized for doing much
else, and they sure do look like they were adapted for flight, they must
have flown.  

It's a matter of relative commitment.  I understand that pterosaurs walked,
and I imagine they probably were considerably more agile on land than they
appeared in "Walking with Dinosaurs" (_Ornithocheirus_ in that case).  I
also understand that animals that fly can be fully capable of other means of
locomotion.  But perhaps it is the most derived body plan that is considered
most persuasive -- the anatomy of a creature that has "burned its bridges"
so to speak.     

In this light, when I consider the diminutive _Microraptor gui_, with its
many bird-like characters and its lengthy hindlimb primaries reaching down
to its toes, I wonder how it would have arrived at such a body plan but in
the context of some kind of aerodynamic behavior!  I'm not pretending to
understand how it used its "hindwings," mind you.       

Dino Guy Ralph
Docent at the California Academy of Sciences
Dinosaur and Fossil Education
Member of the Society of Vertebrate Paleontology