Re: Dromomeron and Lagerpeton query

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message ----- 
From: "David Peters" <davidrpeters@charter.net>
Sent: Tuesday, July 14, 2009 9:36 PM

> Seeking an opinion here.
>
> Since Dromomeron and Lagerpeton are known principally from hind limb 
> materials, its not surprising that the recent matrices of Nesbitt et al. 
> 2009 (JVP) based on Irmis et al. 2007 (Sciene) had a larger than typical 
> number of characters devoted to the hind limb.
>
> Is that a bad thing? I'm thinking of Bennett's rejection of hind limb 
> characters in a similar matrix in 1996.

I haven't read that paper. Can you find any that are correlated?

> BTW, if you add Tropidosuchus, Chanaresuchus, Cosesaurus and 
> Huehuecuetzpalli to the Irmis et al. matrix, these all end up as 
> Ornithodires. What can we do to fix this?

Ehem...

*cough cough*

Did you keep *Euparkeria* as the outgroup? Because that's what the outgroup 
is in the Nesbitt et al. paper (Irmis is the 2nd author). If you run an 
analysis where *Allosaurus* and *Huehuecuetzpalli* are part of the ingroup 
and *Euparkeria* is the outgroup, you have to _expect_ getting random 
garbage as a result. Especially if there are no characters in the matrix 
that are informative for large-scale diapsid phylogeny.

Remember: if you don't explicitly specify an outgroup, PAUP* uses the first 
(topmost) OTU as the outgroup.

In this case, you'd either have to use *Huehuecuetzpalli* as the outgroup or 
add a non-crown-diapsid outgroup to the matrix.