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Re: origin of bats/reply 2 to TMK
David Marjanovic writes:
----- Original Message -----
From: "Erik Boehm" <email@example.com>
Sent: Wednesday, June 25, 2008 2:13 AM
While the presence of what appear to be wings does not prove they were
used for flight, it is the best explanation.
Well... *Velociraptor* had wings, too, yet it clearly didn't fly.
Perhaps not as an adult. Has anyone ever tested the 'Juvenile Volancy'
theory for larger dromaeosaurids?
Sparrows seem to get by on stubby little wings, although if you scaled them
up non-allometrically they'd be land-lubbers. Perhaps the smaller mass and
larger relative forelimb size of a very young *Velociraptor* may have enable
some degree of volancy, which it grew out of as an adult. Certainly many
modern animals spend more time in the trees as juveniles than as adults
(Komodo monitors for instance). Just exchange 'trees' for 'trees and/or air'
in the case of dromaeosaurids.
Feathered forelimbs would have still been useful in adults, although for
non-volant activities such as display or brooding. Juveniles however
generally don't need to perform sexual displays or to protect eggs. Lions
don't grow manes until they're old enough to need them, and juvenile
peacocks don't have large tails, since these are expensive structures to
grow and maintain (too expensive on juveniles anyway, who have no immediate
need for them). So the presence of fully developed 'wings' on juvenile
dromaeosaurids like 'Dave' the *Sinornithosaurus* tends to suggest other
functions are more likely (at least initially).
GIS / Archaeologist http://geo_cities.com/dannsdinosaurs
Melbourne, Australia http://heretichides.soffiles.com