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Re: Dromomeron and Lagerpeton query

----- 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?


*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.