Re: At long last! Turner, Makovicky & Norell on dromaeosaurids

[Tim Williams <tijawi@gmail.com>]

I wrote:

>  But this was difficult for cursorial animals that still had a
> fairly cranial center of mass, and hip-based stride generation, and
> needed a long tail for balance.


Oops, that should be "caudal", not "cranial".



Jaime Headden <qi_leong@hotmail.com> wrote:

> Consider at least that, if Senter's analysis is correct (as has been followed 
> since), *Incisivosaurus gauthieri* should have a postcrania much like that of 
> *Protarchaeopteryx
> robusta*: short tail, longish neck, lanky legs, and relatively long arms. 
> Compared to the body proportions of microraptorians, which have a very long 
> tail to compensate their
> total body length. I'm not quite sure about the effectiveness of even large 
> sterna when they are not fused to one another, and if we presume this is the 
> adult condition (size
> disparity may suggest this wasn't the case), the shoulder apparatus would 
> have been highly unstable for holding the limbs out for any sort of sustained 
> flapping or even
> gliding.


But is the shoulder apparatus of _Protarchaeopteryx_ any less stable
than that of _Archaeopteryx_ and _Microraptor_?  I wouldn't have
thought so.  They're all about the same.  It is isn't until the level
of _Jeholornis_ that we see any real reinforcement of the shoulder
apparatus.







Cheers

Tim