Re: Haplocheirus and Gregory S. Paul

[Tim Williams <tijawi@yahoo.com>]

Mark Pauline <markpauline@rocketmail.com> wrote:

 
> Wouldn't you agree that, since a 4-winged configuration is
> now seen in the basalmost and/or oldest members of the
> dromaeosaurs (Microraptor) and troodontids (Anchiornis), and
> since their sister group is the Avialae, that it is far more
> likely that they all three inherited aerodynamic behaviors
> from the ancestral paravian than that they each acquired
> them independently? I know that we must hold out the
> possibility that Microraptor and Anchiornis didn't glide,
> but the body masses are so small, the arms are so long, the
> sterna are so big and ossified, and the feathers are so long
> and form such large wings  that it really seems more
> likely than not that they glided.


Try as I might, I can't find anything to disagree with here.  ;-)


I suspect a great deal of experimentation in aerial locomotion went on in the 
Paraves (perhaps deeper), by various lineages, including basal birds.  


> If you do agree, then aren't the larger, more derived
> deinonychosaurs secondarily glideless?


Yep.


> If so, aren't "neoglideless" deinonychosaurs the most
> parsimonious explanation?


Yep again.  Though I baulk at the prefix "neo" in this context.  Not your fault 
at all, but the term 'neoflightless' makes me wince.  


I'd say things like _Velociraptor_ and _Deinonychus_ shed the gliding abilities 
of their basal paravian ancestors, and focused on using their forelimbs for 
prey capture.


Cheers
Tim