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RE: Of course nonavian dinosaurs could fly - duh

Gregory Paul wrote-

> It is true that cladistics does not automatically reject a dinosaur
> arboreal origin of avian flight, but most cladistics have presumed it does do 
> so.
> Why? In part because if birds evolved flight from the ground up then only
> running bipedal theropods could be their ancestors, not those quadrupedal
> arboreal thecodonts climbing about in the trees. Meanwhile birds could not be
> dinosaurs if they evolved from quadrupedal arboreal archosaurs as they
> anti-dinosaur folk think. It has been a simplistic argument of convenience on 
> both
> sides.

Honestly, the theropod+ground/thecodont+trees dichotomy might have been popular 
in the 80's and 90's, but since Microraptor's discovery most theropod workers 
and thus most cladists have abandoned it as false.  To continue pushing it as 
being a cladist agenda that has been disproven by the latest particular fossil 
is as bad as when Czerkas did the same thing in 2002 for Scansoriopteryx (which 
I criticised as being untimely then too).  I don't think cladists have ever 
posited ground-up flight specifically to be incompatible with "thecodont" 
ancestry either, especially since most never thought the BANDits' "quadrupedal 
arboreal thecodonts" ever existed (neither Longisquama nor drepanosaurids are 
archosaurs and only the latter are demonstrably arboreal and quadrupedal).  The 
reason BAD cladists were ground-up was because we never had evidence of 
arboreal theropods and parsimony suggested they did not need to exist (the BAND 
arguments for trees-down were and are based on flawed notions of "knowing" 
which way to evolve something is easiest and on misinterpretations of paravian 
anatomy you've corrected in DA and elsewhere, so even if they're right it won't 
be for the right reasons).  But few authors in the 90's and onward ever 
suggested arboreal theropods couldn't exist (that's the BAND line again, from 
the Scansoriopteryx and Cryptovolans papers), just that known examples weren't 
well adapted to it.  Even now there are good reasons to question how arboreal 
basal paravians like Microraptor, Scansoriopteryx and Archaeopteryx were, and 
how much they had to do with the origin of flight in any case.  Too much has 
been assumed from the position halluces were crushed flat in, the utility of 
single phalangeal ratios and such without broader examinations of morphology 
and diversity in recent birds.
I'm glad you've been vindicated by complexly feathered maniraptorans, but 
wouldn't want to see you fall into the BANDits' recent habit of saying the BAD 
cladists are stuck with orthodoxies from the 80's and 90's*.
* Though one way which I'd agree with you is using strict parsimony to judge 
whether aerial locomotion is basal to Paraves and/or Maniraptora and whether 
feathers are basal to Dinosauria and/or Ornithodira.  Here I think the 
lingering attempts to state convergence are unjustified and will only seem more 
strained as further examples of big winged maniraptorans and feathered 
non-coelurosaurs are discovered.
Mickey Mortimer
The Theropod Database - http://home.comcast.net/~eoraptor/Home.html