RE: Ornithomimus had feathers and "display" winglike forelimbs

[Brad McFeeters <archosauromorph2@hotmail.com>]

I'm not 100% convinced that Ornithomimus had pennaceous feathers or 
pennibrachia, even though the distribution and orientation of the markings on 
the arm is suggestive of that.  Zelenitsky et al. (2012) described the markings 
as evidence of "type 3 feathers or higher," but since there are no barbs 
preserved, all that can really be said is that they do not resemble the type 2 
feathers.  The morphology of the individual markings on the adult Ornithomimus 
forearm also seems consistent with the non-pennaceous type 1/EBFF display 
feathers of the new Beipiaosaurus (Xu et al. 2009), for example.  Beipiaosaurus 
is a basal maniraptoran yet has no evidence of pennaceous feathers, so perhaps 
this is the more conservative interpretation on phylogenetic grounds?

  

> Date: Sat, 27 Oct 2012 17:00:56 +1100
> From: tijawi@gmail.com
> To: dinosaur@usc.edu
> Subject: Re: Ornithomimus had feathers and "display" winglike forelimbs
> 
> I'm surprised! For me, this discovery was unexpected. I fully
> expected ornithomimids to be feathered - but NOT to have long
> pennaceous feathers sticking out of their arms! It's nice to be
> surprised.
> 
> Before this discovery, I had deluded myself into thinking that large
> proto-wings (pennibrachia) were unique to Maniraptora, and probably
> originally evolved for aerial locomotion (parachuting/gliding). So
> much for that hypothesis! But it's fun to have an hypothesis that can
> be tested - even if it's refuted.