Re: Concavenator corcovatus, a new humped carcharodontosaurid from Las Hoyas

[Tim Williams <tijawi@yahoo.com>]

"Jura" <pristichampsus@yahoo.com> wrote:

> Sad, it really just reads like the authors want these
> to be quill knobs more than anything else. Maybe the actual
> paper offers better insight.


Hmmm... I really don't see why the idea of quill knobs in a carcharodontosaur 
is so controversial.  We already know that _Velociraptor_ had them.  
_Velociraptor_ couldn't fly, and there's no compelling evidence that it evolved 
from flighted ancestors.  So _Velociraptor_ tells us that the presence of quill 
knobs cannot be assumed to indicate flight ability.  _Concavenator_ tells us 
that quill knobs can exist in non-maniraptorans.  

One possibility is that the quill knobs anchored spike-like integumentary 
structures along the ulna in _Concavenator_ and _Velociraptor_.  These spikes 
may have therefore been quite widespread among theropods, but did not always 
leave an osteological 'footprint' (= quill knobs).

This isn't my idea, but comes from Darren Naish over 10 years ago:

"Another thought it that some non-avian theropods could have modified 
their primaries into stiff, spike-like structures that could not have 
been fouled or snapped in predatory strikes."

http://dml.cmnh.org/1999Feb/msg00470.html




Cheers

Tim