RE: Mesozoic roots of parrots and passerine birds

[evelyn sobielski <koreke77@yahoo.de>]

>   It was my interest when it came out to plug this into
> several large avian morph matrices. Problematically, those
> matrices do not include the diversity of sampling nonavian
> dinosaurs that would be required. There simply isn't an
> analysis that covers both bases, because for the most part,
> there needn't be at this time. Obviously, a super-sized
> matrix sampling all of the stem of *Aves* and many members
> of *Aves* itself would be grand (using the crown=total clade
> definition for that taxon), and the only reasonable way to

The Livezey/Zusi matrix might also be interesting if you want to work closer to 
the crown.

> test it. Otherwise, I'd use Cau and Mortimer's various
> matrices for their sampling size when it comes to
> nonavialaean theropods and avialaeans separately to test one
> aspect. Combining the two would be a project I do not think
> any one group could attempt, and would have to be done by
> greatly expanding and sampling one of these to include the
> data in the other. 

This'll be a problem for the LZ matrix too (of course). I'm presently right 
there, and it's not really nice. Anyone trying such a thing better get the 
material/taxa the original authors sampled for comparison, because it's often 
not clear where to draw the line between character scorings, and character 
descriptions are bound not to be 100% clear in any large matrix (the *authors* 
know what it means, having sampled dozens of taxa. But to readers it is 
sometimes not quite as obvious from the description alone). 

Sometimes you can only say "OK they defined this here feature as character # 
state x, nonwithstanding what the actual description seems to suggest" and work 
with that.
When integrating matrices, it is also easier to compare scorings of common taxa 
alongside the integration, rather than just working from character 
descriptions. In Livezey (1982) - the "Gruiformes" paper - some characters are 
equivalent but (from the description alone) not well comparative to those in LZ.

Regards,

Eike