RE: Jinfengopteryx elegans the troodontid

[Tim Williams <twilliams_alpha@hotmail.com>]

Mickey Mortimer wrote:

> I'll save my final judgement until I get the data matrix of Ji et al. 
> (since
> they include Sinovenator, and Jinfengopteryx does not clade with it), but 
> it
> seems we have the most complete troodontid known, and the only one with
> preserved feathers.

Ji Qiang and Ji Shu'an (who were part of the team that described 
_Jinfengopteryx_) were also the first scientists to describe 
_Sinosauropteryx_.  In 1996, these same authors regarded _Sinosauropteryx_  
as a bird on account of its feathery body covering.

The _Jinfengopteryx_ specimen also contains small oval structures "reddish 
yellow in color" within the body cavity.  Ji et al. (2005) offer no firm 
conclusions on what they are; they could be ova, but the authors do not seem 
too enthusiastic about that conclusion.  They could be "seeds or nuts".  
(Warning: Rampant speciulation ahead...)  If _Jinfengopteryx_ is a 
troodontid, and if the things in its belly are indeed seeds or nuts, it 
would offer the first evidence for the diet of a troodontid.  Some authors 
have suggested that troodontids were omnivores or herbivores, not dedicated 
carnivores like their velociraptorine relatives.  The feet of 
_Jinfengopteryx_ (although poorly preserved) lack the raptorial refinements 
of other deinonychosaurs and _Rahonavis_, but are more like _Tochisaurus_ or 
_Borogovia_.


Tim