RE: Feathers on dromie's digits and Shoehorning (Augury and Alva rezsauria)

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

Luc Bailly wrote: 

> And it's always the same discussion: either _Archaeopteryx_ was rather 
> a seaside bird (as on HP Dan Bensen's paintings), or it was capable of 
> perching on trees - 

The thing is, at this primordial stage of avian evolution, a specialized
perching foot may not have been all that important.  _Archaeopteryx_ and
friends had a functional manus (though, as Alan Gishlick has found, the
hands of Archie and dromies alike probably had limited mobility, at least
compared to the ancestral theropod condition.)  This means that locomotion
up trees, or roosting behavior, may have been quadrupedal for the first
birds.  Again, this is just like juvenile hoatzins.


Ken Kinman wrote:

> The point is that "Alvarezsauria" should probably have never been 
> proposed to begin with.  I regard it was a form of *shoehorning* to
> group genus Alvarezsaurus with mononykiforms.

And that specialized claw on the manus... ?

> More recently Sinovenator was shoehorned into Family Troodontidae.

Go tell the authors of the _Sinovenator_ paper.

> I don't think this is a good practice, and when it affects 
> formal nomenclature, it just adds to the confusion once the premature 
> assignment is overturned.

The confusion may be yours alone.  And I would not regard a shift in
_Sinovenator_'s position as resulting in (or from) "confusion".  Like very
other taxon, _Sinovenator_ goes where ever the data take it - and data sets
improve with every new discovery.


Tim

------------------------------------------------------------ 

Timothy J. Williams 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 3163