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Re: SVP Details II
Mickey wrote: "Hartman concludes that lengthening of primary and caudal
feathers in maniraptorans provided pitch control and stability to short
duration leaps on to prey (as has been hypothesized for dromaeosaurids). He
thinks this shows that wing and caudal feathers may have evolved in a
First of all, I want to thank Mickey for taking the time to provide a
SVP summary to the list. Since he was covering such a large quantity of
talks, this is certaainly not meant as a criticism of his explanation of my
presentation. I did, however, want to clarify the logic in my arguement.
The anti-bird/dino types have often cited hypothetical models of
evolutionary pathways to flight that state in-effect that it is impossible
for flight to have evolved from terrestrial cursors. They also argue that
known theropods are not arboreal, ergo birds could not have evolved from
See my other post, or Gishlick's analysis, for evidence on why
theropods could not have been arboreal scansors. It may well be that we
will find arboreal theropods (yes, I know of the long fingered critter, and
no, it is NOT arboreal, unless it brachiates). My main thesis was that
there is no barrier to evolving flight within a terrestrial context, so
other hypothetical models should not be used to critique phylogenetic
analyses unless their is unambiguous fossil evidence for a particular mode
of evolving flight.
In fact, my talk did not actually deal with the change-over to flight,
but rather with pre-adaption to flight by evolving aerodynaimc surfaces.
The model does in fact cover this change-over, but my talk was long enough
as it was, so everyone will just have to wait for it to be published.
After highlighting some functional aspects of my aerodynamic model, I
presented a couple converging lines of evidence that suggest that this _may_
have been the evolutionary pathway that maniraptorans took on the way to
I had also made some phylogeneticly based predictions on future finds
as well as unstudied anatomy on known taxa, but alas, I had already taxed
the time my excellent moderators could alot me, and I had to skip this
Until these predictions are published and there has been time for other
workers to confirm whether any of the predictions are accurate, I will not
claim that birds leanred to fly "from the ground up." I do hope, however,
to counter the use of other models of flight evolution to critique the
excellent phylogenetic analyses currently be done.
That's it, thanks,
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